yes I would start indoors if you want blooms at a reasonable time frame. A shot of half strength fertilizer once a month and plenty of light and warmth. Giddy-up!

Hi, Zeedman. thank you for this information. The pictures are fantastic!

So are you saying that you keep the heat mats going under the seedlings the whole time they are indors? In the past, I have tried growing the plants on in my basement where the temperature tends to stay in the low to mid sixties. Too cool for good growth? I have a light set-up in the main part of my house where I could grow four flats. I can move it to my MIL's side of the house where the temperature stays at 75 or so, or in the main part of the house where we keep the temp at 68 degrees. What would you recommend?

Hi Donna,

"So are you saying that you keep the heat mats going under the seedlings the whole time they are indoors?"

I don't have enough heat mats to do that, so when I repot them from 3.25-inch pots to 5-inch pots, they are "on their own" with just the heat from the fluorescent lights, which is better than nothing.

"In the past, I have tried growing the plants on in my basement where the temperature tends to stay in the low to mid sixties. Too cool for good growth?"

Too cool for germinating zinnia seedlings. They would germinate poorly, if at all, in the 60's. Zinnias like hot weather. Mine are also in the basement in a utility room with the hot water heater and furnace, but I keep the doors at least partly open to get some heat from the furnished area of the basement. And I have quite a few fluorescent lights, so they provide some heat when they are all lit. They are on a timer to turn them on and off for a 16-hour "daylight" period. I plan to move some of my larger plants upstairs in front of south-facing windows to get some benefit from sunlight. They will still get some fluorescent light to extend their daylength to 16 hours.

"I have a light set-up in the main part of my house where I could grow four flats. I can move it to my MIL's side of the house where the temperature stays at 75 or so, or in the main part of the house where we keep the temp at 68 degrees. What would you recommend?"

The zinnias would germinate better in the warmer area. I keep mine under a humidity dome to keep the medium moist until they emerge. Then they come out from under the humidity dome, or they will get spindly.

In the absence of a humidity dome, make sure the surface of the germinating medium doesn't dry out until the zinnias emerge. One of those little "spritzer" sprayers (like an empty Windex bottle, well rinsed out) could help with that. As the seedlings get their true leaves, they would benefit from more light if you could move them and your lights in front of a sunlit window.

If that is not convenient to do, adjust the lights to keep them about two inches from the leaves, to maximize the lighting effect.

ZM

Donna, the zinnia don't need heat once the seed are all germinated. As you know, I sow all my seeds in dense rows and transplant them as soon as they are about an inch tall or so. But as soon as I see their little heads peeking up out of the potting medium....the plug to my heating cables is pulled.

The heat makes them spindly in a hurry. Cool temps is best for that growing on stage, especially under the less than perfect lighting situation found inside.

Thanks, you two! If memory serves correctly it was germination that was my biggest problem in the past. I am sure I can get them enough heat to germinate, especially now that I know I can plant them densely at first. Once I separate the seedlings and put them in individual pots I will send them to the basement to see how they do. I am so excited to learn something that will make my seed starting even better!

It is about 7 weeks until my frost free date. On the Hazzard's website, with regard to Profusions, it says "seed to sale in 7 weeks". I assume this means until blooms. Do you think that four inch pots will be large enough for a 7 week lead time or should I wait two or three more weeks to get started?

This is all such a great help! I cannot tell you how much I appreciate both of your generous sharing of your knowledge and experience.

By the way, if anyone else is watching this thread, I am going to include a link to a thread over in the Vegetable Gardening Forum. Read it all the way down and you will find some very valuable info on seed starting. Watch the "Tomato Man" video that is linked there, too.

Here is a link that might be useful: Read this and learn!

Hi Donna,

I read your linked thread with interest. I have several pots with multiple seedlings in them right now, because I planted some old seeds that had a low germination rate with as many as 9 seeds per pot. Some pots produced only one seedling from that (a few got none), but several got two or three or even four germinations. I think I will try to "re-pot" them into separate pots. I think that is a skill I need to learn. I have in past years had some success in letting zinnias grow to first bloom in that situation, and cull all but the best bloom by snipping off the rejects at the soil line, but that does "stunt" the remaining plants.

However, in the past I didn't mind doing that so much, because I do cull aggressively in order to get significant improvements in my zinnias. When I am hand pollinating my zinnias, I want to be making crosses between only "the best of the best". Knowing that I will be keeping only the best specimens at bloom time, I do set them out or sow them in-ground closer together than I would normally, knowing that I will be opening up spaces when I remove the rejects. In some cases, that leaves quite a bit of open space, but that can be a benefit to the remaining plants, like last year in the case of this spreading zinnia. This was a single plant.

{{gwi:2619}}
That specimen was a hybrid of hybrids and seemed to be a mutation of some sort. The plant seemed to be a shrub and it spread across the ground, eventually producing dozens and dozens of blooms. I never saw anything like it before, so I designated it as a "breeder" and crossed it with other unusual specimens and selfed it as much as possible, although it produced very little pollen of its own. There are species of zinnias that are true shrubs, but this was garden variety Zinnia elegans (now referred to in academic circles as Z. violacea). I have no idea whether its unusual plant habit was an environmental response, or genetic. Perhaps this year I will know as I grow some of its progeny.

"Do you think that four inch pots will be large enough for a 7 week lead time or should I wait two or three more weeks to get started?"

I usually have my seedlings in 5-inch pots by 7 weeks. Also, following Johnny's Seeds advice to set them in-ground one week after the safe no frost date, that would be 8 weeks from now. I think you should wait two or three more weeks to actually plant the seeds, but in the meantime, you could do some preparatory work. If your pots and trays have been used, as all of mine are, you will want to wash them. I never cease to be amazed at how much time I spend washing pots and trays.

And I have a couple of fluorescent fixtures that have "died" and need to have new ballasts installed. I have several extra ballasts on-hand for just this situation, but it takes me an hour or so to refurbish a fluorescent fixture. Indoor gardening can be busy, busy.

ZM

You are so right about the time required to wash pots. Oh well, nothing in life is free. I will wait a couple more weeks before I get started with the seeds. Thank you for this valuable timing advice.

That is quite a zinnia there in that picture! It rather reminds me of a large sized Profusion in its habit. Very interesting and would be great in a border, not needing to be staked. I hope you can do something with it.

Isn't it fun to learn a new skill? I can tell you that I have read prodigiously on gardening for twenty years or more, and I don't recall ever reading anything about this re-potting technique until here on the Forums. The combined skill set of our members is truly a treasure.

Informative seedling pics, Zen - thanks! :0)

Donna, do you not use heat mats or buried cables for your potting medium? I guess, if you are sowing directly into cell packs, you'd need to use heat mats. If you grow lots of plants, that could be expensive. By using flats for germination, you'd cut back drastically on the space that required soil heating. My cable has an in-line thermostat that maintains the soil temperature at around 75F. I'll just be using two flats (trays) and plan on germinating about 600 or so plants this year. Zinnias will all germinate in a couple of days, if not overnight.

Here's my time saving tip for cleaning those pots, trays, and cell packs. At least, I 'think' it saves time, lol. The minute I am finished with any piece, it gets rinsed out with a strong spray of water so that no potting medium remains. An easy task since they are still moist. After air/sun drying, they get stacked and put away. I never wait to do them all at once. Don't forget that UV waves are great for sterilization of surfaces!

At the beginning of a new propagating season, I simply fill my kitchen sink with a 10% bleach/water solution (or stronger) and bring in the stacks of everything for a short soaking. I've also done this outside in a large plastic storage container. I also soak any small tools and utensils I may use at this time, too. No washing or scrubbing required since everything was sprayed clean immediately after using.

I've learned through experience to store everything in heavy duty plastic bags for the winter. Black widow spiders have a VERY strong affinity for stacked containers of any kind. Just saying....

Great tips, rhizo! I have done the soaking thing before and had great success with it, but was afraid to say so on GW for fear that it's "wrong". I need to be more disciplined to do the strong rinse out at the time of transplanting.

I have always sown my seeds into cells. I do have a couple of heat mats which I usually reserve for seeds that I know need pretty high heat. But the last two years I have been using the "hot spots" in my home for germination. I have one set of commercial Light stands that holds four flats at a time. It's fairly easy to move around. My mother in law lives with us and keeps her bedroom and hall at 75 degrees or more, so I have the light stand in there right now. When I started eggplants and peppers last year I took the stand into a small extra bathroom we have and set up a small space heater in there, and just kept the room at eighty degrees for a couple of days. Pretty low tech, but it worked.

BUT, now that I know that I can sow so many plants into a tray at one time, and that it's actually to their advantage to do so, that is how I will finish up my seed starting! That one heat mat will got alot further now!

In the end, I seriously doubt I will spend anymore time doing it this way than I would have meticulously sowing one seed at a time into all those cells and then having to re-sow the skips. And then, I have plenty of room for all of them to grow on down in the cooler basement.

How on earth did people learn these skills before the internet?....

Just an update to this thread. I started my zinnias five weeks ago and they are getting ready to bloom. Thanks to both of you for your help. I have had the best looking seedlings this year EVER. I started setting them out into the garden this past week. We had a good rain the day after and they all put on noticeable growth. I ended up using a blend of Uproar Rose Zinnias, Cramer's Burgundy Celosis, Purple Passion Cuphea and rose colored Cleome in the background areas of my perennial bed. Along the front edge I used yellow Profusion zinnias mised with Lavender Vinca and Evolution Salvias. Also mixed in some Cuban Gold Durantas for a pop of chartreuse. I think it will be a beautiful bed this year.

This next week I will plant my driveway beds with a mix of Yellow Profusions, Fire Profusions and the new Scarlet Zahara Zinnias backed with Zowie Flames and Mystic Spires Salvia. If I can get these out this week I will have knocked out about eighty percent of the dozen or so flats of flowers I started.

All the tomatoes are in the ground and going like gangbusters. I do so love spring!
Thanks to you both for all your help!

Sounds GREAT!

I sowed my seeds indoors two days ago and many of them have germinated already!

Amazing things, seeds. I never get tired of the process.

Wow! I can't believe the spread on that 1 zinnia plant.

Hi Rose,

That "shrub zinnia" was possibly the most unusual zinnia I have grown. After a couple of killing freezes, I was cleaning up the garden, removing all the dead zinnias and putting them in big black plastic bags for our trash pickup, and I got to see the "skeleton" of the shrub zinnia without the cover of live leaves.

Exposed like that, the structure of the plant looked almost vine-like. Its side branches seemed to grow in an indeterminate fashion, like the difference between indeterminate tomatoes and determinate tomatoes. By the time they had grown a couple of feet, the side branches could no longer support themselves as cantilever structures and they drooped and rested on the ground and continued to grow, all the while putting out side branches of their own.

In several places the vining branches had struck roots into the soil they were resting on. The structure of the plant reminded me a bit of Bermuda Grass, a plant that I am not fond of. I will be growing its progeny out of curiosity, but I have to admit that I am ambivalent about it. And I am still uncertain whether its unusual structure was genetic, or a response to some unusual environmental factor.

This should be an interesting zinnia year for me, because I am growing several crosses involving unusual parent specimens. Crossing mutants with other mutants can produce some odd stuff. Hopefully some of it good.

ZM

How do you keep your zinnias so compact? I've had stretchy plants and am wondering if I've given them too much P or if my temp is causing the stretch

Hi golfcole,

"How do you keep your zinnias so compact?"

I think the most important thing is to give them enough light. That means keep the fluorescent lights within a few inches of them. And I have my timers set to give them very long "days", with 18 hours of light and 6 hours of dark. This time of year the sun is higher in the sky and you probably won't get any significant amount of direct sunlight through a window, so just concentrate on keeping the fluorescent tubes close to them.

Nutrition-wise, use a balanced formula, fairly dilute. I give them an initial dose of Better-Gro Orchid Plus, one teaspoon per gallon. Then I switch to one-quarter teaspoon per gallon for maintenance. When they start to bud out, I blend Better-Gro Orchid Plus with Better-Gro Orchid Blooming formula, which has a higher percentage of Phosphorous. Zinnias are heavy feeders, and in containers you can expect to have to feed them every two or three days. Be on the lookout for deficiency symptoms. You might need to add some soluble Calcium, like Calcium nitrate, if your water supply doesn't contain some soluble Calcium. My Premier ProMix has a little Calcium in it, but only enough for about three weeks of zinnia growth.

Also, be on the lookout for Boron deficiency symptoms. Good complete nutrient formulas contain some Boron, but apparently zinnias like twice as much Boron as orchids. I use a little Boric Acid powder purchased from a drugstore. I make a stock solution of one-quarter teaspoon Boric Acid per gallon, and add one cup of that stock solution to each gallon of complete nutrients for the initial treatment and half a cup per gallon for maintenance.

Boric acid powder dissolves very slowly in cold water, so I heat a cup of water in the microwave, pour that in an empty water bottle, add the quarter teaspoon of Boric acid powder to the hot water, swish it around until it dissolves, and add that to the gallon jug and fill it up to create a gallon of stock Boric acid solution. Discard the water bottle. You don't want to drink any of the Boric acid.

Some water supplies have plenty of Boron and Calcium in the water, so it can be helpful to have access to an analysis sheet for your water. I have to add both to our well water.

ZM

This post was edited by zenman on Wed, Apr 24, 13 at 1:39

Hi golfcole,

(this duplicate deleted)

ZM

This post was edited by zenman on Wed, Apr 24, 13 at 1:37

Yikes!! Some kind of communication glitch created a duplicate of that message. I think I will try to edit away the duplicate.

ZM

This post was edited by zenman on Wed, Apr 24, 13 at 1:34

Awesome I'll give that a try and see what I come up with. Thanks alot

Hi everyone, was reading old post about zinnia's indoors. I found that using a 20$ lamp and the spiral bulbs help thingds grow faster. Am bnow trying it with zinnia's buut im going to wait till febuary to try this

Zen-Man, thank you SO MUCH for the great zinnia advice & photos!! I am close to Houston (Huntsville) and next year, I think I'm going to start them in pots outside and skip a step. This year, I started them on my back porch using the winter sowing method. They are only about 18 days old at this point. I transplanted them on about the 10th day, left them on the back porch for 3 days and then put them in the full bore sun. They are looking pretty good. Thank you again! The photos were particularly helpful as was the growing time line!