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Timing of seed starting

Posted by karin_mt 4 (My Page) on
Wed, Dec 29, 10 at 13:06

It's that time of year - every day brings a new, glossy catalog to your doorstep. Each page is bursting with mouth-watering photos of the sweetest, the freshest, the healthiest plants ever. So many possibilities!

With a greenhouse, the proposition of when to start which seeds is a bit tricky. I'm curious at what other people do. Obviously everyone's circumstances are a bit different, such as where you live and if your greenhouse is heated and what you are growing. But this forum offers a great way to learn from others.

So here's my list - please add yours!

My greenhouse is in Montana, unheated but pretty well insulated.

mid Feb: Start lettuce, spinach, mesclun, broccoli, green onions, parsley, pansies, alpine strawberries. Broccoli and green onions will be grown inside the greenhouse in ground beds.

mid March: Start tomatoes, peppers. Start basil that will grow in the GH. Plant carrot seeds in the GH ground beds. Transplant lettuces into windowboxes. Harvest first salad!

early April: transplant herbs into windowboxes or larger pots. Harvest lots of lettuce and greens.

mid April: Direct sew cucumbers that will be growing inside the greenhouse. Planted a few seed potatoes in the ground beds as an experiment. (which worked and gave us potatoes in early July). Start flowering sweet peas in 4" pots. Pot up tomatoes and peppers into 4" pots. Plant up various containers of annuals (purchased at nurseries) to get nice big pots before bringing them outside in May. Start more greens.

mid/late April: Major planting of seeds for plants that will be grown outdoors. Start lettuce, broccoli, spinach, green onions, basil, plus cutting flowers zinnias, snaps, rudbeckia.

early May: Harvest first basil for pesto! Plant tomato and pepper starts into ground beds in greenhouse. Pot up remaining tomatoes into gallon pots. Harvest carrots that were planted in GH last fall. (Harvesting the carrots frees up room to plant tomatoes and peppers.)

mid May through late May: Transplant everything outside as needed. Hardy veggies go out in early May with row covers. Tender veggies go out in late May or early June. This year will add row covers for those too. Plant root crops outside.

mid-June: Second round of greenhouse-grown lettuces are done. Switch to outdoor greens. Start heat-tolerant lettuce for outdoor growing.

early July: Harvest GH broccoli; GH tomatoes and peppers growing strong. Outdoor lettuces are at peak, time to start more. (I am terrible at getting lettuce started on time)

mid-July: Harvest first tomatoes from greenhouse! Harvest greenhouse-grown potatoes. Outdoor lettuces/spinach are bolting.

mid-Aug or early Sept: Start new seeds of lettuces, spinach, pansies and greenhouse-grown carrots for fall growing.

Sept - Oct: Spend every free moment harvesting, canning, freezing. Start one last round of lettuces, some of which will overwinter.

Nov: Keep harvesting tomatoes, peppers, cukes from inside the greenhouse, until first deep freeze puts an end to that.

Dec: Plant a few bulbs in the greenhouse ground beds. Harvest lettuces.

Jan - early Feb: Harvest greens occasionally. They grow slowly so we get about one salad every other week.

mid-Feb: Go back to the start of this list and repeat! :)

Phew! I am interested in what timing works for the rest of you. I still find myself lacking in heat-tolerant lettuces to harvest in late July-August. I'm also always seeking the earliest, best-tasting tomato to grow inside the greenhouse.


Follow-Up Postings:

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RE: Timing of seed starting

A quick follow-up.
First, some photos are always good. I've really been enjoying all the photos folks have been sharing lately.

Second - I've found a good record keeping system is key for learning from my mistakes. I have a notebook where I jot down the status of things every 2 weeks or so. I also keep track of how many plants I start and what varieties. Then I fill in notes like "don't bother with these!" and "start these earlier next time!" and "This type is the best yet!"

I rely heavily on these notes and my own editorial comments. It really helps to have the info written down from year to year because there are too many details to remember and it's those little details that can make a big difference. Plus, there is something therapeutic in writing everything down and reflecting on it.


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Anything I have to contribute is purely speculative - first year with a GH. Very appreciative of your time to give me a plan for my first year! I printed off your schedule to use as a guide. Thanks!

I did print off Johnny's Seed - Seedling starting calculator - available on their website but will have to adjust the frost date from experience with the GH - may be of help though. Martha Stewart's Seed Starting Worksheet www.marthastewart.com/seed-worksheet may be a form to use a a guide in developing my own history and notes as you suggested.

Getting started the first year in our GH with seedlings it appears we will need a seedling heat matt and not having an inventory - much - of plastic pots, decided to try the Soil Blockers - mini 3/4" and medium 2 1/4". This GH is opening a whole new world of Gardening for us in zone 3-4 (Wyoming). Mixing the soil has us somewhat concerned - thought we could just use potting soil but guess that doesn't work that well for seedlings?

It may be that the weather report (night time temperatures) is a good friend to make sure precautions are taken inside the GH to protect the seedlings? I assume a good thermometer inside the GH is important to gather data comparing - outside temp to GH temp - (our GH is not heated) in determining what precautions to take in the spring/fall when temperatures drop?

Any experience with starting seedlings is helpful to us!


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i am working on getting a greenhouse together for spring past few times i tried it was too big and i couldn't keep it heated so im going for just big enough this year. i am in Tn.
I am not going to start lettuce and cabbage and things of that nature im gonna concentrate on the main season stuff. most of that will be started in February to be put out in the end of April. hope it works this year.2 types Eggplant, 3 types tomato's, 4 types of peppers, everything els gets direct seeded. i set up a spot in my attic that is heated with lights to start some there in case the greenhouse doesn't work out. i like you pictures looks real nice. heating has been my problem in the past so i hope if i make it smaller it will be easier to keep warm. Im thinking 10x10.


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Hi 7kft,

I am certain that you will have fun and do a very thorough job in tracking your seed-starting this spring. For soil, generic "potting soil" is not worth much. After failing with the substitutes, I now only use "pro mix," which is made from peat moss, perlite and vermiculite. This is produced by Sunshine and other companies. There is also "germination mix" which is the same basic thing but with smaller particles.

The Pro Mix comes in compressed bales. They are expensive, but for us junkies there is no doubt it will all get used up in time! It is also sold in normal sized bags if you just want to try it out.

As for predicting temps in the greenhouse, you can start now by setting up a wireless thermometer that has at least two temperature probes. Make sure it records the max and min temp. Put one temperature probe in the GH and one outside. The base station goes in your house so you can monitor the temps while sipping morning coffee.

Every morning, compare the outside low with the GH low. You will quickly get a feel for how the two compare. Armed with that data, you can start to predict what your greenhouse low temp will be.

Once you've gotten seeds started, you can fine tune the temp by using heat mats on cold nights, moving flats to the floor where it's warmer, covering things, or if all else fails, bring the flats inside the house for a night or two.

Today was warm and sunny in the GH. Our cats love to hang out in there and doze in the cozy warmth. The problem is they will not come out! So I let them spend the afternoon in their own private spa. Happy cats.

Jed - if you are only using a greenhouse to start seeds you don't need too much space, so smaller sounds like a good idea. In TN you should be totally fine getting things started in Feb. If you need just a little heat, the heat mats are a good way to go without heating your entire structure.


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if i may pick your brain a little and run you through my plan real quick i would love to here your opinion. a few years back i built a 10 x 40ft. hoop house out of pvc and i think it was 9 mil plastic i don't quite remember. the end walls i built out of wood for the door frame with a piece of pvc bent in the hoop shape and covered them with plastic. i just couldnt keep the temp up and got frusturated and its been in a pile in the barn since then. so for the plants i am going to be starting i am going to use 16 32 cell flats which should all fit on a piece of ply wood. here it is. i put up this hoop house but keep it at 10x10, then i want to stack bales of straw 2 bales high in a square under the plywood in the center of that square i want to put one of those oil filled electric radiator type space heaters. thats one idea, i figure the heat from the radiator will heat the bottom of the plywood and the bales of straw hopefully heating the entire space. like i said before, previous years i have failed due to not being able to regulate temperature. i have also thrown around the idea of instead of putting the heater in the center of the straw bales, just building a compost pile in the center but for now i think i will try the heater. as for the heat mats you speak of i do not have much experience with them i have a couple but they are the type with no thermostat they just heat up a little bit warmer than the room temperature i will have to look into them a little more and see what is available. any ideas or suggestions would be greatly appreciated


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Every morning, compare the outside low with the GH low. You will quickly get a feel for how the two compare. Armed with that data, you can start to predict what your greenhouse low temp will be.

Then the next step is: if the low temp inside is too low, use water to store heat and release at night. Several calculators out there to determine how much is needed.

Dan


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RE: Timing of seed starting

Jed,

What is your outside temperature? What inside temperature are you trying to achieve? I can't imagine you need much heat to make late-February TN weather work for seed starting.

As I have learned from Dan and others here at the greenhouse forum, plastic coverings offer very little heat retention at night. If it were me, I would invest in a sturdier greenhouse covering and some black water barrels or buckets for heat retention, and then you probably won't need a heater at all.

I don't have any experience with greenhouse heaters, so maybe someone else can add some insight there. Personally, I would be very nervous about putting an oil-filled heater in the middle of a bunch of straw bales, especially with a plywood cover over it. Sounds flammable to me, but like I said, I have no experience there.

There are some great suggestions posted on recent threads. Dan and Jr slick (not sure if that is his handle, but something like that) have outlined various methods for hoop houses and cold frames.

Good luck!


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karin,
we (wife and i) lurk around here a bit. we own a geodesic dome in denver since 09 and have always started our seeds inside under lamps in the house. we're kinda newbies and to be honest we have been flailing a bit with the whole greenhouse thing. today we're going to yank everything and do a soil overhaul on all the beds. wondering what your thoughts are on using agribon inside the greenhouse as an additional cold barrier at night, to be removed over the seed beds as the greenhouse warms up during the day. also, do you do some seedlings in trays and some direct ? we've always used trays but are curious about planting directly to the beds. sorry for the book of questions, your greenhouse is picture perfect by the way.


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Hi Dudley,

I used to start seeds inside with lamps, but the greenhouse with its strong sunlight produces much stronger plants.

I use Argibon and other types of row covers exactly like you describe: on at night and off during sunny days. In the coldest parts of winter, like now, I leave the covers on for the most part unless its actually sunny. Once mid-Feb hits, the greenhouse starts to get a lot warmer and things start actively growing again, so the covers are definitely off during the day.

I start most seeds in trays but I direct seed cucumbers and carrots in the greenhouse ground beds.

I've also had great luck growing greens in window boxes inside the greenhouse. I direct seed into those, using mesclun type seed mixtures.

Good luck with your soil overhaul. That is almost always a good thing to do!


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karin
appreciate the feedback. keep you posted on our progress.


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Hi folks!

I have been organic vegetable gardening in small raised beds for 8 years, 1 year at my new home. I grow almost everything on trellises. I just received a 10 x 12 Harbor Freight GH as a gift. The gift giver's wish is to get me, my seeds, pro mix and fish emulsion out of his basement work room, so I am glad to hear that seeds can be started in an unheated greenhouse!

Once the greenhouse is up later this summer, I will start a log of min and max temps. Thank you for the tip! Minimum temps seldom get below zero here, but I am in zone 6A.
I will have electrical service to the greenhouse. I have been reading everything I can find about passive solar heated greenhouses. I plan to insulate the north wall and the foundation with foil backed insulation board. I will have black water-filled barrels on the north wall as heat sinks that will also serve as supports for the north shelf that will hold the seed starting flats.

I am hoping that heat mats under the seed starting flats and plastic covers will supply enough additional heat at night to enable me to seed start. (Are there more than one kind of heat mat? Mine do not have temperature settings.) I do not want compost in the greenhouse, because I do not want to attract vermin.

I copied the calculations for BTU's needed to heat a 10 x 12 ft polycarbonate gh in Ohio. Thank you for this info! I will research minimum temps in March here and hope for the best the first year.

My foremost worry right now is the foundation and drainage, but I haven't found the specific info I am looking for in any of the forums. We are on 30 feet of clay (verified in the well report). I will need to plan carefully for drainage, especially since I plan to grow vegetables in the floor--cold hardy greens in the winter and long season veggies and cucumbers in the summer. Does anyone have suggestions? I thought about digging out the footprint of the gh and laying perforated pipe that would drain down the hill (is this called drainage tile?). Then I would cover the floor with pea gravel. I would build the beds on top of the gravel with untreated wood and fill with good soil, and fill walking areas with more gravel.

Karin, I looked at the pics of your gh, and I love your stone flooring. I see that you have beds in the floor inside. Can you tell me more about these? How did you plan for drainage?

The county building inspector recommended a cement slab and not worrying about the frostline. There are no legal restrictions on how I may build the gh here. No requirement for a rat wall, either, but I am considering one. The property is surrounded by farm fields.

I'm sorry this post is so long, but it is my first. I was delighted to find this topic with recent posts! I hope I can be helpful to you in the future.

Pat


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Hi Pat,

Congratulations on your new greenhouse - that sounds very exciting. Good for you to be doing lots of homework and planning before you build.

We do not have quite the same drainage challenge that you do. Our subsoil is a compacted, alkaline soil that likes to bond tightly together, but it is not as impermeable as clay. I have not taken any special measures for drainage. The beds on either side of the aisle have been dug out about 18 inches down and filled with peat moss, compost and sand. The following year I added gypsum and more compost to try to break up the mineralized clumps that kept forming. So far, so good. It drains with no problems. (But again, we have OK drainage overall.)

The flooring is done with concrete pavers. They are on a bed of sand that is about 3 inches deep. The edge of the flooring is held in place with a strip of composite "trex" wood. The Trex is crzy expensive but it holds up perfectly well in the high-moisture environment of the greenhouse.

If I were you, I'd be hesitant about a concrete floor. Not only will it not drain, but it will be colder in winter than a dirt floor. Insulating the perimeter of the greenhouse is the way to go - if you do a search you will find more info on this topic.

Good luck! Let us know if you have more questions.
Karin


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  • Posted by alicate SW Michigan zone 5 (My Page) on
    Tue, Jan 10, 12 at 17:43

Karin,

You said in the coldest times of the year (January) you keep the row covers on all of the time except when it is sunny. Two questions for you: First what is the crop that is being grown for this? Second, what kinds of row covers are they?

You have me very excited to try a greenhouse!


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Hi Alicate,

My winter crops are carrots, green onions and various greens (lettuce, spinach, pak choi). Also some flowers and this year I am trying burying some pots of bulbs to see if that might get them through the winter for springtime forcing.

My covers are a thick fleecy fabric that I got at JoAnn's fabric store. It happens to be the right width to fit the width of my beds and of course it comes in any length. It's made from recycled bottles and it's white. Cost is about $5/yard last time I bought it.

I also use the heavyweight Remay type fabric, but at least at our local stores it comes in a big square shape which is not as conducive to the shape of our greenhouse. Also it is not as heavy as the fleecy stuff.

This year, with our non-winter, I have been keeping the covers off and actually harvested a salad last week! That is purely ridiculous, but at least the lack of winter has a small benefit.

Do you have a greenhouse? Or are you still in the dreaming phase?

Karin


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  • Posted by alicate SW Michigan, zone 5 (My Page) on
    Mon, Apr 30, 12 at 13:14

Hi Karin! Actually I am in between dreaming and having one. My husband is actually excited about getting me one and I am considering the Riga V and a couple of others. I like the Riga a lot and am thinking this may be the best for us. My garden is on a NE and SW orientation. I am wondering the best way to orient the greenhouse at this point. Doing lots of research! Thanks for all of the tips!


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Alicate,

Sounds like you are making good progress in forming your plan. Lots of research and thinking about it is a great idea, and getting your husband on board is essential, especially when it comes to getting the GH built.

Have fun and keep us posted!
Karin


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Hi,
I love this forum and was so happy to find the schedule that Karin posted. I also live in Montana and am starting off my first year with a greenhouse. I am wondering if you are able to start any of your warm weather plants...tomatoes, peppers, etc in the greenhouse. I am still having trouble with my transplants being very leggy. Thanks for any input!


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Hi Mull,

Oh yes, I start all my seeds in the greenhouse and they love it in there. I use heat mats in March and parts of April for the warm weather plants.

If your plants are leggy they must be not getting enough light. What is your setup like? Are you starting them inside or in the greenhouse? I used to get leggy seedlings when I started them inside under lights. But it the greenhouse they are stocky and strong.

Congrats on your first season with your greenhouse! They are especially nice in this climate. Where in MT are you?

Karin


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Hi Karin,

Thanks for the response! I start them under grow lights inside on a heat mat. I was worried it would be too cold in the greenhouse, mine was getting down to the 20s at night during March and April. I am considering starting them out there and then bringing them in at night next year.

I live in Cardwell, which is in between Butte and Bozeman. I am really excited to use this greenhouse, but I have quite a bit of learning to do. I started peas and cabbage and the like out there in March, but they seem like they got too hot before they matured so I have just moved most of those cool weather plants outside and am hoping they will take the transplant. The cool nights seem like they are going to be a problem because the greenhouse is nearly as cold as the outside temps are. How does your greenhouse fare at night?


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mull-
I start my seeds in my greenhouse in late-March when it can still get down to freezing at night. However, I have electricity in my greenhouse, and I have my seedling trays on heat mats and under propagation domes, so they remain unfazed. If you can get electricity run to your greenhouse, it will make a big difference. Large heating mats -- big enough for 4 standard trays -- only use about as much energy as a 100 watt bulb. It's also important to use a thermostat with the mats so the plants don't get cooked.


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Hi Mull,

Cool, we are nearly neighbors! :)
Our greenhouse stays pretty warm at night. I think it's pretty well frost free by late March/early April. I can usually expect the low temp in the GH to be 5-10 degrees warmer than the low temp outside. Ours is pretty well insulated (8mm twinwall polycarbonate) and we have a nicely insulated foundation. Plus it is chock full of black water buckets.

If you use the heat mats in your greenhouse you'll be fine - that is, if you have electricity in your greenhouse.

Here's a list of a few things I do to keep things warm in the spring:

- put flats on the shelves during the day (warmer there)
- move flats onto the floor at night (warmer there)
- use plastic domes over the flats and then cover the the whole thing with frost blankets. That will almost always be 10 degrees warmer than the outside low temp.
- If it is really cold you can put your flats on the floor near a couple of black water buckets and put the blankets over both the buckets and the flats. Cozy!
- take off the plastic domes during the day, unless it is really cold AND cloudy. I have cooked more plants this way!

- For the heat mats, I put a couple of sheets of styrofoam underneath the heat mat because otherwise much of that heat is lost through the bottom of the shelf.
- When all else fails, bring the flats inside at night. If I do this I try to limit myself to 1-2 flats because that gets old after a while.

Hope that helps!
Karin


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Karin-
Great point about the styrofoam. I forgot to mention that I also have my heating mats on 3/4" styrofoam sheets, and it works well, definitely saving a lot of electric energy.


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Thanks for the great ideas...any chance you guys have one more? I don't have heat to my greenhouse and it isn't really practical to tie in from my house at this point. Is there a way to get a extension cord in during those cold months without letting all the cold air in?


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RE: Timing of seed starting

mull-
First, of course, only use a heavy duty cord that is rated for outdoor use. Any kind of extension cord is only supposed to be used on a "temporary basis" according to code, so don't let this become a permanent situation by default. Also, do what is necessary to give the cord protection from accidental damage. Finally, don't overload it, especially if it's a long run.

Now, having warned you, what is your greenhouse like? Does it have plastic glazing? If so, drill a hole big enough to accommodate the plug end, or cut off a small piece of a corner. After you pass the cord through, you can patch/caulk it to seal the little hole from air leaks. Does that work?


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Hmm, that's an interesting idea! I like Kudzu's recommendations though. But I guess if it were me I would skip the heat mats and just start the warm weather plants indoors and move them out as soon as possible. I think we're talking about a pretty narrow window of time, right? If you want to start your tomato seeds in late March/early April, then it's not that long until the greenhouse ought to be warm enough to not freeze at night. And at that point you can move everything out to the greenhouse.

Do you have a wireless thermometer in there so you can see the temperature during different times of the day? That's a key thing to do so you can learn what to expect from your greenhouse during different types of weather. Then you'll be able to look at the weather forecast and know when things inside the GH may be in trouble.


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I think I am with Karin on the starting inside business...I already suggested drilling a hole in the greenhouse to my hubby who about fell over:). He has hours and hours of work into that thing and isn't about to go for that.

I do have a wireless thermometer and was a little disappointed by the amount the greenhouse cools off at night, nearly to the same as the outside temperature. It does warm up very quickly though once the sun comes back out. I have been reading about the passive solar heat and thinking about putting some black barrels out there. Does it seem to make much of a difference? I am a little hesitant to fill up the space with the barrels because all my beds are ground beds and I would lose space that way.


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mull-
Try it indoors...however, I predict in your situation that you would have much better results if you used your greenhouse for the purpose intended and had electricity. I started my seeds 2 months ago, and where I live it won't be safe to put out tomatoes for another 2 weeks. They are much faster growing and sturdier being in the greenhouse. I'm a little perplexed over why your husband would have a heart attack over one very small, neatly placed hole...but maybe he'll soften up next year when you want to get full use out of your greenhouse! Lastly, while passive heat can help a bit, it won't make a huge enough difference to be worth it for you. I wouldn't want to lose any space in my greenhouse with barrels. The no-lost-space, easy alternative is always going to be electricity.


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I had a thought about the extension cord - could you dig a hole underneath the foundation and basically tunnel it inside the greenhouse?

But kudzu is right, having electricity opens up a lot of options. Such as listening to nice music while starting seeds. :)


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Did you guys connect right to your house supply before you built? I agree that electricity would be really helpful, but our greenhouse is quite a ways from our house and the outlet we would have to use is outside...probably not a great set up.

I started looking into stand alone power sources (solar, battery with an inverter...) but that is getting quite a bit out of my comfort zone so I think next year I may try some plants inside and some outside with as much physical protection as I can figure out and compare the two results. Have either of you tried the bubble wrap around the walls or anything along those lines? Maybe not, given that you have electricity.

Thanks kudzu for the opinion about the water barrels. I have gone back and forth on that. I'll just continue on without those for now.


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We had electricity and water put in right after the GH was built. Of course ours is right next to the house so it was easy.

I haven't tried bubble wrap but lots of people have. If you search around this forum for that you'll get some more info. Same goes for water buckets/barrels.

I like your idea of trying some seeds both ways. Ultimately we all figure out the best plan for our conditions and I'm sure you will too!


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mull-
The bubble wrap would help retain heat, and its something that doesn't steal any room away. It's like having an extra layer of glazing. Also, this forum has lots of old threads about alternative heating, like solar cells, and that's an expensive thing to do that would also be too much trouble for you. Some people also use ventless propane heaters if they don't have electricity, which can work. However, I prefer the ease of heat provided by electricity and controlled precisely by a thermostat. If you check out the link below, you can read some of the GW posts about heating and heaters.

[I should also mention that karin's suggestion about running the cord under the foundation -- while clever -- is not a good solution since you don't want to be burying any part of an extension cord in the dirt or have it some place where it is in a puddle of water as that can pose a shock hazard if there is any failure in cord jacket. My wiring is underground, running from my house to the greenhouse, but I enclosed it in plastic conduit and used the required wires that are rated for this use.]

Here is a link that might be useful: Ventless heater


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I just finished my greenhouse and now I am researching/experimenting what I can grow and when. I printed off the timing post from Karin in Montana because I also live in Montana (officially in Zone 5 but really more like Zone 3 - 15F on May 15 this past spring!!). Temps are still in the 90's here but I've managed to limit the high temps in the GH to about 6-8 degrees higher than the outside temp with a misting system and solar operated fan. I just planted pelleted carrot seeds in the hope that I can germinate them with soil temps in a raised bed around 80-85F (fresh carrots in November!?). Also plan to try and grow lettuce, spinach, swiss chard and Asian bekana greens as soon as the temps moderate a bit.


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Hi Danr,

What a handsome greenhouse that is! It looks especially sturdy which will come in handy around here. And yes, I can tell by the backdrop that you are also from MT. :)

It sounds like you are off to a great start if you have been able to keep your greenhouse cool in this hot summer. I very nearly bought one of those solar fans but I opted not to in the end. How do you like yours? I love the solar-powered idea.

Your seed starting plans sound spot on to me. I am just getting lettuces going again. I planted them in windowboxes which I put on the floor where they get misted on from above. They sure do like that. It's hard to get them going this time of year but I think we are close to the Big Cooldown. You'll be able to have those greens all through the fall and maybe some will even overwinter for you.

I'm going to hold off on my carrots for another week or two. I just harvested all the carrots out of the greenhouse over the weekend and I got a huge haul of 15 lbs. Those were seeded Sept 1 last fall, and I've been pulling out a couple pounds at a time all through the summer. But now I took them all out because it's getting crowded. I agree that the pelleted seeds are the way to go. Your soil temp is really 80 degrees? That's much warmer than I'd expect, the way things cool down at night.

Good luck and keep us posted!
Karin


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Karin,

So far, the solar fan is working fine. It has a thermostat switch that kicks in when the GH temp reaches 85F. I have two 18x18 louvered vents along the floor on the west side of the GH and the fan is powerful enough to open those vents but not fully. If I have any complaint about the fan it would be its limited pulling power. It is a critical component of my cooling system (the misting system along with the air exchange lowers the temp) and a lot cheaper than running 150' of electrical line!

I am really looking forward to figuring out what will grow when in my new greenhouse. Again, having your original post gives me a great starting point.

The weather forecast looks good for later this week and next - highs in the low 80's instead of upper 90's. I am running out of non-bolting lettuce and need to start more but its been too hot!

Dan


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Hi Dan,

In the absence of an electrical line, your solar fan sounds like an ideal solution. Nice work!

If you still have any non-bolting lettuce you are doing very well. What kind did you grow?

I managed to get the next crop of lettuce up and running. I started the seeds in the house where it's cooler, then kept them in the shade for a week or two, then transplanted them both inside and outside. I'm keeping them under shade cloth and misting them once or twice a day. They seem to be over the hump and look like they'll make it now. In the meantime, we've been having "lettuceless" salads with cucumbers, sweet peppers, carrots and cherry tomatoes. Yum.

36 degrees tonight! I imagine you will have a similarly chilly night. Aren't we glad we have greenhouses! :)


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Karin,

34F predicted for us tonight. I have everything covered - nothing in the new greenhouse yet except some carrot seeds I started in the raised bed.

The two lettuce varieties I am still harvesting are Crisp Mint (which is a romaine) and Red Summer Crisp. The Crisp Mint has just bolted but I am hanging on to a few plants of Summer Crisp but it too is starting to show its age.

It's been a great year for tomatoes (compared to the past two years). I typically grow the 60-65 day varieties - Polbig and Rocky Mountain are doing very well for me this year. I am looking forward to growing a longer variety tomato in the greenhouse next year. How many extra tomato growing days do you think I might gain in the greenhouse based on your experience?

Dan


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RE: Timing of seed starting

Hi Dan,

I had good luck with summer crisp lettuce too. That was the longest-lasting type we had this summer. I can't remember the variety we had offhand, but it was durable and super crispy, almost like iceberg lettuce.

Those sound like good tomato varieties - I will have to look into them. The greenhouse must add 45-60 extra non-freezing days - it's really a lot! (all of April and most of October stay above freezing.) I still go for the early tomato varieties though because I'm impatient. My best early tomatoes have been Matina and Early Wonder. Matina did not enjoy life in the greenhouse because the misting created spots on the skin. Otherwise it was healthy and crazy productive though. They both do well outdoors here as long as they are in a warm, protected spot.

This year I have 'Goliath' growing in the greenhouse as a longer-season more beefsteak-type tomato. It is wonderfully tasty but it cracks and is very watery. So I'm not sure it's the Perfect Tomato I am always seeking. :)


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RE: Timing of seed starting

Karin,
I will have to check out Matina and Early Wonder. I too am searching for the Perfect Tomato. Polbig is at the top of my list right now but I'm always ready to try a new variety.

Tomato cracking is another gardening mystery I haven't quite figured out. Last year all my tomato varieties cracked badly toward toward the end of the season. This year I decided to change my watering schedule and wait for visible signs of wilting before I watered. That translated into a lot less watering this year compared to last. No cracks this year - growing the same varieties. I'm not sure I have it figured out but its another data set in a lifetime trial!


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RE: Timing of seed starting

Hi Dan,

How does Polbig taste? I just looked it up and Johnny's describes it as "good tasting" which is an adjective I usually avoid. I go for the ones with more impressive descriptions. :)

I'm happy to report that the new lettuce crop is off and running. We've had salads the past two nights. I'm in heaven with salads this time of year, with Buttercrunch lettuce, cherry tomatoes (Sweet Baby Girl), cucumbers (Diva), carrots (Nelson), and sweet peppers (Gypsy). These are all the most reliable, yummy vegetables I've come across and I grow them year after year. They are like old friends.

Thanks for the watering tip. I will hold back the water on Goliath. Its neighbor, San Marzano, is extra thirsty and suffers from blossom end rot. But I will just water the San Marzano and skip the Goliath. Do your tomatoes get blossom end rot and if so, have you figured out a cure?

I need to start bok choi, spinach and arugula today. Soon it will be time for those heartier fall greens. I love how the different types of veggies change with the seasons. I find it endlessly fun (and tasty)!


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Karin,

Polbig's taste is on par with all the other early season tomatoes I've tried. I grew up in PA, so none of them taste like a good old-fashioned beefstake! I'm still searching for the early variety that tastes great.

I have had blossom end rot in past years but this year only a few fruits were affected. I think watering (how much and when) is still the hardest part of gardening.


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RE: Timing of seed starting

Yes, I agree, finding the beefsteak flavor in a 60 day tomato is the holy grail, isn't it? Matina has a lovely flavor, but the tomatoes are small so you can't build a sandwich out of big ol' slabs of tomato.

I can report that Silvery Fir Tree, Beaverlodge Plum and (of course) Early Girl do not have that true tomato taste - not worth a spot in my greenhouse!

Blossom end rot is an ongoing problem for Roma-type tomatoes and being inside seems to exacerbate it. I will keep on experimenting. By the end of the season, I have never complained of a shortage of tomatoes though, so it's not exactly a crisis. :)


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RE: Timing of seed starting

Two hard freezes here this week ended a very good tomato/basil/pepper year. Unfortunately, all that hot and dry weather spawned the fires we are enduring. I rushed a few potted annuals ino the greenhouse before the freeze and now they greet me every day in their mid/summer best. I love it!! Another bonus of the cool nights - my strawberries are back in limited production.


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Wow, it got cold enough there to wipe out your tender plants? Bummer. Especially now that it's warm again.

I was out of town for the freeze but my dutiful husband got everything covered. Our outdoor tomatoes, peppers and basil are all in spots that are either covered or sheltered, so it's easy. Good for you to get your potted annuals in the greenhouse where they will last a good deal longer.

I enjoyed lots of harvesting today, which feels proper this time of year. I'm impressed you have some strawberries coming along. That is one thing I have not really been able to grow well.

Are your greenhouse carrots coming along OK? I plan to start some tomorrow.


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RE: Timing of seed starting

I too had everything covered but it got down to 26F. I live near the river bottom so our low temps are often 3-5 degrees lower than the surrounding area. This is why I built the greenhouse!

My carrots are looking good. They've been in the raised bed inside the greenhouse for four weeks. I also planted lettuce and swiss chard in the GH raised bed. They are also looking good but I noticed that the lettuce I sowed directly in the GH two weeks ago has caught up to the lettuce I started indoors a month ago and transplanted. Do you have any problems transplanting lettuce seedlings?


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RE: Timing of seed starting

Well, you are very smart to have a greenhouse then, since you will always get the cold end of cold snaps.

Transplanted lettuce seedlings seem to need some intensive care to get on their feet. Especially when I wind up with several plants per cell in their 6-packs and I tend to break them apart into individual plants. This sets them back a lot and I probably should stop doing that. I pamper the transplants with occasional misting with water and I keep them under a row cover to give them shade. They really appreciate this special treatment.

Despite the needed TLC, seeding them in 6 packs is still easier for me than direct seeding and then thinning. But when I grow lettuce in the windowboxes I think it's easier to just sow the seeds directly.


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RE: Timing of seed starting

This 3-tier seed starter purchased at Gardening Supply Company worked great this year to start our seedlings indoors before moving them out into the Greenhouse - and much less expensive than heating the GH in our climate. We started the Tomatoes in February indoors and saved substantially on the cost of the plants when compared to purchasing starts at a local nursery. We had ripe tomatoes in June and are still harvesting them.


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Karin, So far my greenhouse is staying about ten degrees warmer than the outside temp (that's without sun which is standard wintertime fare around here). I am harvesting a few varieties of lettuce and swiss chard regularly. The carrots are a week or so from being ready - they may not add much growth given the soil temp inside the GH. They are predicting arctic air by the weekend. That might be the first big test.


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RE: Timing of seed starting

Thanks for the pic Dan, it looks lovely in there!
I am watching this weekend's weather too. I still have tomatoes and cukes growing! Not much longer though.

Looks like you can cover things in your raised bed and you will soon see how you can nurse things through the cold temps.

Your petunia basket (wow is that huge and happy) may not be too happy by this weekend though. :(


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RE: Timing of seed starting

Hi Karin! I am starting to think about spring and my first season with a greenhouse. I usually start my seeds indoors under grow lights but I am thinking about using the greenhouse to start all of my seeds. I can run an extension cord (this summer I am running electricity to the greenhouse!) to connect a 4' seedling long heating pad. I'm not worried about the temps as much as I am the light. Do you think my greenhouse will provide seedlings enough light to keep them from getting leggy? Indoors I have a system where I can raise and lower the light fixtures - I keep the lights within an inch or two of the seedlings as they grow.


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Hi Dan,

Exciting to be thinking of seedlings again!
For sure the greenhouse will be light enough - it will be a lot brighter in there than grow lights.

The temps are harder but it sounds like you've got that under control. When are you thinking of getting things started?


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RE: Timing of seed starting

I may be overconfident in the temperature control department. Today I had 86F in the GH and 35 outside! I didn't have the fan on however - I will be counting on outside air ventilation to keep the highs under control. Do you start any seeds in the GH?

I will be in Hawaii until Feb 22 and plan on starting some seeds soon after I get back. I'll be paying close attention to your timetable that started this thread.


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RE: Timing of seed starting

Hi Dan,

I start nearly all my seeds in the GH. Sometimes I germinate them in the kitchen because it's warm but as soon as they germinate they go to the GH for the sake of good light.

For temperature regulation I stay pretty busy making adjustments during the day. Clear plastic covers on, then off when the sun comes out, then on again in the evening, then flats on the floor covered with a blanket at night, etc. It's not a passive method. But I like the routine of visiting the greenhouse during the day, especially in late winter when it is the only place around that is warm and green.

Late Feb sounds right to me, for the cold-tolerant plants. I am getting lulled by the warm weather we're having now, but I will wait until late Feb before I start up again.

Hawaii - nice! Have fun!


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RE: Timing of seed starting

Burpee just announced a new free Gardening app "Gardening Time". It may be an option to keep timing of seed starting and garden planning organized. Glad Burpee has taken this step to provide us gardeners with a tool for garden/GH planning. Check it out on google play or Itunes.


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RE: Timing of seed starting

Karin, Happy spring (-like weather)! I noted you start basil that you intend to grow inside the greenhouse in mid-March. My greenhouse is definitely getting warm enough during the day to make basil happy but I am guessing there will be some nights inside the GH when the temps are 35F or so. I'm wondering how you protect young basil starts during the inevitable cool nights when greenhouse temp are in the 30s?


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RE: Timing of seed starting

Hi Dan,

Hmm, interesting to look at the list I originally posted here because this year I am going to wait one more week, for the reason you mentioned. It was 31 in my GH this morning.

That said, it's not too hard to keep things warmer at night by putting the flats on the floor and covering them with a frost blanket. A seedling heat mat would easily do the trick too.

Worst case you can always bring the flats inside if its going to get really cold.

Happy planting!
Karin


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RE: Timing of seed starting

Very informative long-lived thread. GH gets built this year after nearly forty years living & gardening at the same address. Been studying Eliot Coleman's The Winter Harvest Handbook like I used to cram for final exams. He advocates the lightest row cover, Agribon 15, for continuous winter cover except for when they are harvesting during the warm part of the day. He is Zn 5 in Maine and harvests year round from mostly unheated or some minimally heated GH's (adds just enough heat to keep them above freezing.) He's tested using heavier material but found it didn't work as well because it prevented the ground from heating up during the day. Light weight covers get enough frozen condensate on the underside to mimic heavier cloth and reflect the radiated heat back into the plants at night. He does a lot of experimenting and is gracious in sharing the results.
I plan to supplement the heat for my GH from the wood stove in my shop. The GH will be attached to the SE side of the shop and there is a door that will open into the GH. I intend to put a fan in the doorway and blow heat into the shop during the day and out of the shop at night when I have a fire going. The shop is very well insulated and requires only one fire every day or two to keep it from freezing in there. Hope it works.
Karin, your original post is wonderful. A great resource for guys like me. Thank You!
The link is to my newly designed website, complete with several blogs, one being for my gardening. I live in Lively, hence the punny name.

Here is a link that might be useful: Lively Dirt - The Garden Blog


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Lively, I can tell you are going to have a great time with your greenhouse. I think that a science or engineering background really helps, as the whole thing reminds me of a big science fair project. Keep us posted as you finalize your plans.

Karin


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Karin,
I would appreciate if you could show some pics of your beds, and how you are using the fabric to warm them.
Papa Jamie


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RE: Timing of seed starting

Hi Karin! Happy spring (almost). I started my greenhouse raised beds last week. It was a cold and sunless Feb so my plans to start the greenhouse bed early were foiled once again by Montana weather. I have lettuce, radishes and spinach up but no sign of life yet from the carrots or kale. I ran electricity to my greenhouse last spring after my last post and now have a heavy duty fan on a thermostat that kicks in when the GH temp reaches 80F. It has made a huge difference in managing the hot temps in the summer. I grew longer season tomatoes and peppers inside the greenhouse without a problem. Except for the aphids I battled all summer and fall! I am pretty sure they were came in on some plants I bought from commercial greenhouse.I will be very careful in the future with anything I don't grow from seed. Live and learn. I also added a shade cloth to the south facing glazing because I had some problems with delicate seedllngs frying in the hot sun while I was away at work. I used 70% shade cloth that I can remove later in the year. How is it going in your part of the state?


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Hi Papa Jamie,

Here is a pic of the lettuce blanket. Basically it's metal hoops spaced every 3 feet or so, then blankets draped over the hoops. I've had great luck growing things in window boxes, because they are portable. So the window boxes go on the floor, covered with the blankets. When it was really cold this winter, I put about 4 layers of blankets over everything. Must've worked because all the boxes survived.

Dan! Hello to you too.
I just got my first seeds started today. I should have started earlier, but winter is very full with skiing, so time and energy are rare things to have! Nonetheless, I had a wonderful morning of getting things underway. Cleaning the greenhouse has got to be one of the best-feeling chores ever.

I agree that frying seedlings is a major hazard. It can get insanely hot, even this time of year. I have found that the plastic domes that cover the seed-starting trays can be really hazardous. Luckily I work from home so I can keep an eye on things. We use 50% shade cloth plus a misting system and fan, and that's worked well for us.

I battle aphids too. I noticed that ants "farm" them so I use borax-based ant traps in the GH and that helps a lot. Also, there are some plants that aphids love so much (spinach) that it's just not worth it to grow it in the GH.

I hope you get everything off to a good start!


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Another pic of the blankets and the beds. And the daffodils! They are always a treat when everything outside is still all snowy.


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RE: Timing of seed starting

I like the idea of the daffodils in the GH. I will throw some in next fall. I also read about the ant/aphid symbiosis. I placed the same ant traps as you described around the outside of the GH. It didn't seem to help that much. I went through a lot of neem oil last summer. I am hoping the 20 below zero temps we had this winter killed every last one of them inside my GH!


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Try the ant traps inside the GH. I don't think cold weather bothers them too much, since they seem to be here every summer regardless.


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Karin - you did post photos of your GH/plants - somehow I missed it. Your lettuce is looking good - as always! What do your tomato plants look like? When do you plan to plant them in your GH this year?


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No tomato plants quite yet Hudson. I'll get them started very soon. Actually, I am still seeking some new sauce-type tomato types, I've been reading about some with resistance to blossom end rot. We'll see.

These last few winters I am always a little late getting started in the spring. You are much more on top of it that I am! (but your photos and prompting do help shoo me along...)


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Karin,

I have had consistenty good luck with Bellstar - a short season determinate sauce variety. It looks a little suspect early in the year and then produces like crazy. I will be trying the Heinz variety from Territorial Seeds this year as well.


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Thank you for posting the pics, Karin. That really helps. My brain likes pictures, and now I get what you are doing. I have never used anything like this in my GH, so I guess I better get my little woman to start doing some sewing. Thanks for all the great tips on here.


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RE: Timing of seed starting

No need for sewing Papa Jamie. You can just cut them to size and they don't fray or anything. So your little woman is off the hook!


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