weirdtrev,

All good advice. I usually grow extra, but that is if our area gets hit with some bizarre frost in May and/or if my transplants for some reason bite the dust. I hadn't thought about early germinating and early transplants. Also, I had read about the black plastic idea as well and thing this would be a relatively easy/cheap amendment to add to the garden to increase the soil temperature.

Thanks for the response.

smithmal

Many techniques are "tried and true" but how well they will work all depends on the vegetable in question and how actively involved you want to be.

Pepper plants are so heat dependent that I have found no benefits (or methods) that will gain me anything with early transplanting.

Tomatoes on the other hand, especially early varieties, do quite well in WOW (Wall o'Water) or similar type cloches and consistently tolerate the early chills and produce early.

Summer squash (I plant early to avoid SVB and squash bugs) also do well under row covers as needed.

Leafy greens do fine for me under just a floating row cover and cole crops need only an occasional covering with an inverted pot or bucket (with holes) or a layer of row cover.

Of course a tunnel, either high or low, opens up a whole world of early planting possibilities but they do require close monitoring for temps to prevent heat-build up once the sun comes up.

Hope this helps some.

Dave

Last year I bought some starts from Home Depot that were very early for my area - eastern Massachusetts. People were commenting on boards like this one how ridiculous it was for the big box stores to sell plants before their time. We had a warm spring, and I covered my plants over several nights to protect them from frost, and I got a great jump on the season. It's a gamble to plant early, but nothing ventured, nothing gained. What can kill a farmer is a minor annoyance to a gardener.

This year I'll be starting some crops in a 4x8 hoop house. When it starts to get too warm, I'll take it down - very simple. It's just a cold frame really, and people have been using cold frames for hundreds of years. My cold frame will just include in-ground planting along with the seedlings waiting to be transplanted.

To extend, use a well sealed hoop house, with a drip line and no mulch. Concur that with the grading Dave provided. Melons basil and okra are similar to peppers. Eggplant is slightly more cold tolerant. Beans are OK with cold air temperatures but need warm soil, so laying down a little black plastic (no cover) for a week is all that is needed. Squash needs warm soil, too, but since it is germinated indoors that is less important. So, to summarize: hoop house for transplants, black plastic for direct.

I've been doing some surfing to see if I can see some experimental soil temp data comparing different methods in regards to vegetable gardening. As of this moment, I haven't come up with a "catch-all" experiment comparing soil temps between methods such as:
1. Black plastic
2. Hoop houses/row covers
3. Wall O' Water variants
4. Raised beds vs. level beds

I think this type of data would be helpful to know how soon one can either sow or transplant plants into their beds in their local zone. If anyone could fill in the blanks in terms of average increase in soil temps with the options above and/or a combination of options above it would be appreciated.

I did find an interesting page on soil warming cables (see link below) and was wondering if anyone had any experience. For owners of large gardens, I can't see this being an option, however for smaller plots and/or raised garden beds, this might help out alot. In the link, the OP discussed the benefits (with photos) of using soil cables with row covers.

Cables don't look to be too outlandish ($40-$50 for 60' of cabling).

smithmal

Here is a link that might be useful: Soil Warming Cables

Also found a site which plots soil temp data for all states which may be of some interest so some of you. Attached is a image of MD (Ellicot City sensor data). The different lines represent different temp readings at different soil temps (going from -1" to -80").

Looks like temps fluctuate in MD soil between 50F-60F for 8" to 20" depth in April (at least in the year 1998). My understanding is you want your soil temp to be at least 45F before attempting to transplant. These reading though look a little high. If true, it would seem the rational for pushing the transplant date in my area (middle of May) would be ambient air concerns rather than soil temps.

If that's the case, warming up the soil is not too big of a concern for transplants, it's the freeze frosts that are the biggest hurdle for planting out early.

smithmal

Here is a link that might be useful: Soil Climate Analysis Network (SCAN)

This post was edited by smithmal on Mon, Jan 7, 13 at 16:17

Here in NH we can get a light frost in mid-September but if I can protect the bush beans for a couple of nights, we can get a last crop of beans. A few years ago before I started using a portable low tunnel covered with Agribon fabric, I lot my late planting right when they were blossoming. My husband built a wooden base that holds the plastic hoops which are covered with the fabric. We had a problem in the spring with winds so something like this needs to be anchored.

I have neighbors with a high tunnel who were eating tomatoes July 1. This is our first winter with a high tunnel so I'm hoping to have some early tomatoes and zucchini. In the meantime I have winter hardy veggies (beet greens and spinach) that are doing fine in the high tunnel with additional fabric covering the beds. Last year spinach over-wintered in the open garden and started growing again very early. I'm not going to bother calculating soil temperatures. I'm going to do like above and just try it with a few plants.

Every year is different. Last year I direct seeded green beans on March 28th and melons, cucumbers and zucchini on April 1st in black plastic outside. The soil temps were in the low 60's to low 70's with black plastic. We never had another freeze or frost until mid October. That was just strange.

However the only true way to extend the season repeatedly is with a high tunnel or a greenhouse.

Here am some or our tomatoes from last year towards the end of April. They were planted out on March 15th. I probably could have backed up that date 2 weeks, if the plants would have been ready.

{{gwi:9880}}

Here are the cherry tomatoes.

{{gwi:9881}}

We started picking cherry tomatoes at the end of May and big tomatoes in early June. Our largest harvest week ws actually the last week of June. Our frost free date is May 15th.

Jay

Holy smokes! Your high tunnel is awesome. Any one know of a link to a DIY high tunnel and/or Greenhouse that can be fitted over an existing garden?

Jay, is your tunnel permanent (it looks like it must be). How does it hold up to the wind? How much does something like that cost to erect?

smithmal

Smith, as it happens I'm helping a farmer friend put up a high tunnel right now, 21 feet wide by 90 feet long. At that scale and caliber it is costly, 7-8k I would estimate.

I believe one can order the smaller rolls of ag-grade poly online, and building a small version with bent wood hoops or pvc pipe is quite doable. Generally every region has a wholesaler or manufacturer of the metal pipe hoops, giant rolls of poly, and all the other stuff required. Around here it all comes from a place in NH.

Smith:

How handy are you? I have built all my high tunnels from scratch except the big one in the first picture. I bought it used and had to take it down and rebuild it. Not a hard process, but it did take some time.

My remaining 5 tunnels, 3 stationary and 2 movable are all homemade and cost between $500-$800 to build with plastic. My oldest tunnel 5 or 6 years old.

Here is my oldest tunnel. They are 18 by 45 ft they are made with wood, PVC pipe and chainlink top rail. They are my own design and have been copied many times and are successful for many other people all over the US. They get you into high tunnel growing at a low cost and so you can start making money faster. I have turned my profits into more buildings and bigger buildings.

{{gwi:9882}}

Here are my movable tunnels. They are 16 by 32. They have 3 spots each to move over. This is an old picture, before I prepared all three movable spots.

{{gwi:9883}}

I am putting a link below to my website, check it out. If you do, click on the link at the top called presentations. It will take you to some presentations I have done about these structures and several others

How to they hold up to the wind? Living here in North Central Kansas, thunderstorms and high winds are the norm. We have done 70 plus MPH winds and 14 inches of snow and they are still around. We have also had near misses with tornadoes, we lost shingles one time, but the tunnels still stand.

Jay

Here is a link that might be useful: Check out our Farm Blog

Jay,

Your presentation was very thorough, thanks for providing it. I have been decidedly converted into a hoop house addict!

Couple questions:

1. It would seem that the "arch type" hoop houses provide more headroom than the "hoop type." Are there any pros/cons to choosing one over the other? Which design do you think would have the most structural stability and longevity? In terms of longevity, I noticed you provided estimated "shelf-lives" of different hoop house designs. With PVC constructs, do you find that the pipe cracks overtime from environmental stress or from tension in the pipe from bending it? With an "arch-type" design, I would assume the torsion stress would be much less as the PVC isn't bent. Would you think for this reason one could expect better longevity for "arch-type" designs?

2. I already have a 4' high paddock fence surrounding my plot which I'd like to use as side walls and attach the PVC anchors/supports to. My intention is to design a "hoop-cap" to add on top of the fence which I could easily dissemble when the summer heat arrives. My biggest concern would be snow/wind destroying the cap during the late winter/early spring. I notice in your presentation you showed a picture of a hoop house destroyed under the weight of snow. What design elements should I be thinking of to make sure this does not occur?

3. How do you ventilate your hoop houses? Is this usually done by opening the covered side walls? I saw a video presentation where the OP incorporated adhesive zippers to the walls/ceilings which could easily be opened/closed when more/less ventilation is necessary. My concern though is that this would reduce the integrity of the structure. Any thoughts on this?

4. What is your temperature threshold where you open the house for ventilation? In the spring/fall do you open it during the days and close it at nights? Does humidity ever become a concern within the hoop house (fungal disease, etc.).

5. Do hoop houses cut down on plant stress due to pests in your experience?

6. Do you think it wise to do a double layer of plastic for better insulation/longer growing season for a hoop house "first timer?" I was a little confused within the presentation when you indicated that you were "blowing air" in between the layers. Does this mean that your layers are air tight and blowing air in between them provides an air insulation pocket (i.e. like a double pane window)? If so, how do you make your two plastic layers air tight?

7. Do the hoop houses that you've built essentially give you a four season growing period, or is there a period where the ambient temp is too cold to allow for plant germination/growth? If so, what is the lowest ambient temp that a hoop house can expect to protect crops from?

8. In a zone 6b/7 scenario, at what ambient temp do you think I could transplant into the hoop house. Do you transplant at all, or is you hoop house insulated enough to allow for sowing seeds.

9. I noticed you don't use raised beds at all, I'm assuming with a hoop house, your soil temps are warm enough so this is not necessary. I have raised beds, but if the hoop house provided enough insulation, I would have more "real estate" if I removed them and planted directly into the soil.

10. Not related to hoop houses, but I was wondering if you find hybrids are beneficial over heirlooms or vice-versa when growing crops for money. I typically try to choose heirlooms for seed saving reasons, but I know hybrids have their place too. Are the variants you listed in your presentation your general "staple" for growing crops each year?

Thanks again for all your information and the link to the presentation. It was very informative and I really like how you showed your design maturation of hoop houses through trial and error.

Much appreciated,

smithmal

This post was edited by smithmal on Tue, Jan 8, 13 at 4:27

I will try to answer your questions below each question, that way I can keep them straight.

Couple questions:

1. It would seem that the "arch type" hoop houses provide more headroom than the "hoop type." Are there any pros/cons to choosing one over the other? Which design do you think would have the most structural stability and longevity? In terms of longevity, I noticed you provided estimated "shelf-lives" of different hoop house designs. With PVC constructs, do you find that the pipe cracks overtime from environmental stress or from tension in the pipe from bending it? With an "arch-type" design, I would assume the torsion stress would be much less as the PVC isn't bent. Would you think for this reason one could expect better longevity for "arch-type" designs?

Arch is called Gothic and that is what my movable buildings are. They are actually steel. The hoops are one 26 foot long solid piece, just FYI. The only time my PVC ones have broke is after a huge storm and it was only one or two pipes. They split at the top where I put the carriage bolt through. That was very early in the project and had never happened since. Gothic shed snow better, hoops are probably easier to put up. Gothic gives you higher side walls to ventilate and more room along the sides.

2. I already have a 4' high paddock fence surrounding my plot which I'd like to use as side walls and attach the PVC anchors/supports to. My intention is to design a "hoop-cap" to add on top of the fence which I could easily dissemble when the summer heat arrives. My biggest concern would be snow/wind destroying the cap during the late winter/early spring. I notice in your presentation you showed a picture of a hoop house destroyed under the weight of snow. What design elements should I be thinking of to make sure this does not occur?

Well that picture is from Missouri and they had 2 or 3 feet of snow in one storm. It was a steel structure. It sat down in a low area and a lot of snow blew in on top of it. They people didn't remove the snow and that caused the failure of the structure. Would using your fence work, yes. How wide is it? I have put in some 2 by 4 "Beams" in the center of all the buildings to add strength. Also, for piece of mind, I added two more beams on the sides. My original idea was to remove these during the summer, but I never have gotten around to do that so I just leave them up all year.

Here is a picture of the beams. This pic was taken in December after I transplanted a bunch of crops.
{{gwi:9884}}

3. How do you ventilate your hoop houses? Is this usually done by opening the covered side walls? I saw a video presentation where the OP incorporated adhesive zippers to the walls/ceilings which could easily be opened/closed when more/less ventilation is necessary. My concern though is that this would reduce the integrity of the structure. Any thoughts on this?

I ventilate with the sidewalls pulled up and opening the doors on the end. Do not use adhesive zippers, they fail and fail at the worst times.

4. What is your temperature threshold where you open the house for ventilation? In the spring/fall do you open it during the days and close it at nights? Does humidity ever become a concern within the hoop house (fungal disease, etc.).

In the early spring, fall and even in the winter Ventilation is always an issue. Depending on the weather, wind, temps and size of plants and what is planted decides when to open up. I have reached mid 90's in the tunnels with snow on the ground. In the summer, it is much hotter. Humidity is a concern, but you will learn how to manage it.

In the spring, usually open them up around 9 to 10, it just depends. Then close them around 5 pm or before, depends on the lows. Once the lows don't go below 50-55 degrees, we usually leave them open all the time. Also, you have to close them when a storm hits. We have had some close calls, but we have never lost a building due to wind because we always shut them. The bad thing is you also have to reopen them after the storm. The worst is storms that happen at night. I have ran outside, more times than I care to admit to, in my PJ's and sneakers to shut all the hoop buildings. Nothing better than a brisk 3 am sprint to wake you up! Now if there is a threat of rain, I just drop the sides and leave the doors open until it gets closer.

5. Do hoop houses cut down on plant stress due to pests in your experience?

Hoop houses can cut down on pests, but it also provides perfect environment for pests. Aphids, spider mites are a real problem, sometimes. They do cut down on environmental stresses such as wind and hail.

6. Do you think it wise to do a double layer of plastic for better insulation/longer growing season for a hoop house "first timer?" I was a little confused within the presentation when you indicated that you were "blowing air" in between the layers. Does this mean that your layers are air tight and blowing air in between them provides an air insulation pocket (i.e. like a double pane window)? If so, how do you make your two plastic layers air tight?

I do not have double layer of plastic on any of my buildings. One reason is lack of electricity to each building and added cost. Some say it is really good, I haven't spent the money to find out.

7. Do the hoop houses that you've built essentially give you a four season growing period, or is there a period where the ambient temp is too cold to allow for plant germination/growth? If so, what is the lowest ambient temp that a hoop house can expect to protect crops from?

We grow year around. All 5500 square feet of high tunnels are producing crops right now. We spread out our planting so we can try to have a continuous production all winter. We just finished up our third winter market last weekend. We also have an online market we run weekly. In the winter you are more or less just "Harvesting" We try to have all our transplants in by Thanksgiving. These little kale, lettuce, chard, bok choys, napa cabbages, and many other Asian Greens will grow in the cold weather and will handle the freezes at night. You won't be growing warm season crops in Dec-Feb without added heat. With that said we will transplant in tomatoes in March and keep them going through Thanksgiving time. That is long enough for me! We also will start planting carrots this month and onion plants in early February.

8. In a zone 6b/7 scenario, at what ambient temp do you think I could transplant into the hoop house. Do you transplant at all, or is you hoop house insulated enough to allow for sowing seeds.

See previous answer. The soil never freezes in a high tunnel, maybe along the sides, but not in the middle. We will start planting carrots in Jan for harvest in late April and early May. We start transplanting tomatoes when the soil temps hold at 60 degrees. Usually this is around St. Patties Day or before. We will transplant in lettuce earlier than that. My problem is I don't want to plant too early or I won't have a strong market to sell everything at.

Several years ago we had a very cold spring, we had a light frost in early May! That year I planted rows of quick growing crops besides the tomatoes. We had lots of produce for the early markets. We wouldn't have had nearly as much if we wouldn't have done this. It really boosted our sales that spring.
{{gwi:9885}}

9. I noticed you don't use raised beds at all, I'm assuming with a hoop house, your soil temps are warm enough so this is not necessary. I have raised beds, but if the hoop house provided enough insulation, I would have more "real estate" if I removed them and planted directly into the soil.

I do use raised beds, the are just raised soil beds and they aren't boxed in with wood. The soil temps are a little higher with them.

10. Not related to hoop houses, but I was wondering if you find hybrids are beneficial over heirlooms or vice-versa when growing crops for money. I typically try to choose heirlooms for seed saving reasons, but I know hybrids have their place too. Are the variants you listed in your presentation your general "staple" for growing crops each year?

I like heirlooms, don't get me wrong, but unless people are going to pay more for them, then IMO, you will loose money growing them. If I had to live off of Brandywine tomatoes that I grew they would be about $200 a piece. Now my hybrids are cranking out 20-30 pounds a plant. I do grow Cherokee Purples, because they look different. Most people don't see a visual difference between an heirloom red and a hybrid red.

I also find the heirlooms I grow are less consistent. That really is hard for me to use valuable space and may or may not get a crop. SO I have leaned more towards hybrids, but a few heirlooms here and there.

I hope I have answered your questions, let me know if you have more.

Jay

Jay,

Thanks for your responses, they were very helpful. In terms of storm damage, I'd be at a bit of a disadvantage of opening/closing the side walls in preparation of an oncoming storm as I have a hour+ commute to work from home. Generally in MD though the majority of our storms are in the summer and by then I'd remove the "hoop cap."

In terms of installing the sheeting onto the hoops I was thinking of the following product (see link below).

What do you use to attach your films to hoop house's supports and how is it done?

Considering I am almost two zones higher than you and I have 1' high raised beds I may be able to get a way with a 4 season growing cycle for summer veg's. Once I get the hoop house up, I'll monitor the soil temps and report back.

Finally, how do you amend your beds in your hoop houses every season? I'm assuming you wheel barrow in manure etc. in? Also, what products do you use?

Looks like this is turning into a "hoop house" thread...

Thanks,

smithmal

Here is a link that might be useful: Greenhouse Film; 6mil

Smith, I don't think you need a hoop house in 6/7. Instead, my main advice is to push the season all you want with cool-season crops in spring and fall, but don't stress tomatoes, peppers, etc., to grow when it's cold since your climate has plenty of warm weather.

Simple milk carton cloches will make it possible to set out lettuce, spinach, kale, and cabbage in March. They will come out in June, allowing plenty of time to grow something else in their place. Your climate also has such a nice, long fall that it can be used to grow wonderful leafy greens and carrots.

Jay, where you have that break from bend to straight, instead of a radius, you don't find the poly wears early? Or are the sides separate pieces?

Ones I have worked on the whole house is one pull of poly.

Planatas,

For the most part, I would agree with you although here in MD we, at least I, have pretty bad pests problems. I'm hoping to solve this by growing and/or harvesting the veggies when they are not around.

I've tried unsuccessfully to grow squash, cucumbers and eggplant and get annihilated by beetles, squash bugs, stink bugs, and squash borers. I've tried all sorts of organic measures to no avail (covers, neem oil/kaolin clay, and good old bug squashing). I've called my local extension and they've admitted it's an issue and I might think about employing more drastic toxic measures (which I'd like to avoid).

Also we get pretty significant humidity and heat which causes a lot of blossom drop/fail. I've thought about trying to plant for a fall harvest (as the buggies would be gone by then) but with veggies that have long harvest times (some of the beefsteak tomatoes I like are 90+ days after transplanting), I'm not sure if I could get them in after the bugs leave and still get a harvest.

Also, this is pretty inexpensive, low labor and could really increase my growing season in the early spring and late fall.

smithmal

Have you looked into the short, half-high tunnels called caterpillars for your cucurbits? Where pest pressure is really bad they are proving useful, sometimes kept closed all the way to harvest with bees introduced inside. My pest pressure is less severe in the mountains, but I still have to keep most cucurbits except butternuts covered with tulle to keep them healthy.

You're not the only one in the midAtlantic/Chesapeake area to report lotsa bugs. I think there is a prevalent air movement pattern that moves southern species up quickly in spring and leaves them there to enjoy the humidity.

Planatus,

I've tried the tulle route for both cucumbers and squash to no avail. They still find their way in there (via smell). It's a bit of a pain as you have to self pollinate the flowers and those dastardly bugs still manage to find their way in.

I found the following for a movable caterpillar design (see link). But it would seem to be not that much different than a hoop house? Not sure how this would help with my bug issue during the "infestation" period of late July/August. Please explain.

Thanks,

smithmal

Here is a link that might be useful: CatTunnel (moveable)

Update:

I've gotten all my materials to build the hoop house frame and shell. As mentioned, I have a 16' x 16' garden area which is fully enclosed within a 4' paddock fence.

My thought is to design a greenhouse that has a permanent base with a detachable cap/roof. In terms of the base, I'm going to use eight 4' pieces of 1" PVC (4 on each side) which will be attached to the fence using galvanize 1" pipe straps and also screwed to the fence rails/posts using 1 1/2" wood screws.

Attached to each base will be a 1" PVC union assembly which should allow me to easily unscrew the roof at each base point once the temp warms up. These were the most expensive materials (about $5 each) but in the end it should make installing/removing the roof/cap pretty painless each year.

The roof will consist of 1" PVC "joists" that will be attached to the base and in the middle using 45 degree PVC adapters. The base will be also built up an additional 2.5' at the union point to increase the head space (see attached jpg for simple design illustration).

All the PVC materials and strapping cost about $100 (purchased at local Home Depot).

The shell will be the 6mm greenhouse film linked earlier in this thread.

My questions with this design are:
1. Should some sort of support ridge be installed in the middle to support the center of the arch? I wasn't sure if it would be needed with a 16' x 16' sized hoop house.

2. What type of clips should be used to connect the film to the PVC framing? I've read that one can make their own using cut thin walled PVC material that will essentially snap over the preexisting framing, but wasn't sure if that was the best route.

3. I haven't yet figured out how to make the front/back in a fashion that is easy to installed and remove. When I put up the front, I'll be temporarily removing my existing gate for a larger door. Any guidance would be appreciated.

I'm super excited for this project and actually started my seedlings last weekend for a mid-March transplant within the hoop house. This should extend my growing season (at least on the front end) by a full two months (zone 6b).

smithmal

This post was edited by smithmal on Tue, Feb 5, 13 at 16:16

By the way, I purchased "Four-Season Harvest" (Amazon link below) to read up on gardening within hoop house structures and found the table below comparing ambient temps to covered and covered + cold frame temp scenarios very illuminating.

At night time, you'd get a 10F-15F bump in hoop house temp vs. ambient temp. If you add a cold frame to your hoop house (row cover, low tunnel, etc.) you can get an extra 15-20F bump for extra protection. At day time you're looking at a +60F bump with the hoop house and with an additional 20F bump under a row cover!

It would be interesting to get soil temp readings. I think I will do this once the hoop house is up. Does anyone know of a decent inexpensive soil thermometer I could purchase?

Pretty impressive to say the least.

smithmal

Here is a link that might be useful: Four-Season Garden (Eliot Coleman)

you guys should use my planting technique i have planted out my tomatoes plant on or about feb 15-25 depending the year in wall o water under hoop houses for last 7 years. I live north west of Baltimore. the most important secret is making sure the soil does not freeze and is covered with hoop house before the cold weather sets in. you can also use soil heat cables to prevent it.

Just got to the kitchen gadget aisle and pick up a dial thermometer one that is about 4 to 6 inches long. Don't get a Meat thermometer. They are usually $3 to $5.

Jay

thegreatcob,

Awesome that you can start your tomatoes so quickly! You must be getting your beefsteaks in by May/June! So you use a hoop-house, with a wall of water and heat cables? Do you find that all three are necessary? I was hoping to get by with just a hoop-house and maybe row covers as I am using 1' raised beds which should warm up and retain heat pretty well. What soil cables did you use? Can you enlighten us on what type of soil temps and ambient air temps you are seeing inside your hoop house?

Jay, I purchased the dial thermometer (see link below). Thanks for the advice. I got a stainless steel one which is waterproof from Amazon. Hopefully I purchased the correct one.

smithmal

Here is a link that might be useful: Supco ST08 Stainless Steel Pocket Dial Thermometer

the heating cables are there are only used when temps stay below 30 f for weeks at time and lots of snow.

The Temp differences on the chart are a good reference for Averages only. Under certain circumstances the inside temperatures may actually dip below outside temperatures. One research project a few years ago reported that and recently another researcher confirmed that it does happen because inside air is dryer and therefore the Dew Point is lower, allowing lower temps to occur.

My point- always have a backup plan to whatever venture you take. If you go with a system that has no room for a backup plan then you will be a victim of the system you chose.

Be skeptical of the Four Seasons claims. If the sun isn't out, you get little heating during the day. A few days like that, combined with big night time drops, and you lose whatever daytime heating you get very fast at night. Any time you're not actively heating the interior, you're losing heat. Fast. Even a double layer of plastic only helps a little.

For a home gardener I would suggest Wall o Waters. I have a pile of them for sale actually. The trick with planting peppers and tomatoes early is to warm the soil first not just protect the plant.
Plastic mulch and then Wall o Waters or other products placed out a few sunny days before planting is good.

Or put out your cages, cover each in red tomato bags from Terriorial, then cover the whole row with clear plastic, then leave a few days and plant tomatoes.

thegreatcob,

I will be measuring my soil temps with the dial thermometer Jay suggested. At what temperature point should I seriously consider employing soil warming cables? Does the temperature of soil fluctuate much between the day and night under a hoop house (I'm specifically concerned about raised beds for this question)? What brand soil warming cable would you suggest?

Thanks,

smithmal