Great show Jack!!

I swear you always are reading my mind. Thanks you answered my questions that I had on yesterdays show. My brain hurts and is going 90mph with so many ideas. I live in WA and it’s been below freezing for the last 5 days or more with freezing fog. The tomatoes and the peppers I have in the green house / hoop house are so far so good. I do cover them with just an old bed sheet at night. They are looking a tad stressed.

Last year I put low tunnels over the tomatoes and covered that with old flannel sheets. We went down to 19F for two nights in a row (very unusual) well things froze. This year I have a pile of piggie and alpaca poo with some straw in there and that is the only thing that I have done differently. Oh yes and I have straw mulch. I hardly had to water at all this year using straw mulch. That could be another factor in why the plants are hanging on. I haven’t watered in a while like weeks.

Herbs oregano sage chives rosemary thyme are all doing very very well. The basil not so much looks a little droopy. Lack of water cold? combo? I may try to trans plant and bring into the back porch and then into the house.

Thanks again this was a fantastic show and perfect timing.

PS When I used contractors plastic at the end of the season it started cracking by the next season it was dust. Had millions of tiny pieces to sweep/rake up. I still use it from time to time in a pinch. However only for limited periods as I don’t want to face that mess again.

I have very thin wire cable with turn buckles at the end thread old bed sheets on to it (most of my sheets were open at one end those that weren’t I just made a little slit in the seam.) they are attached to the side of the greenhouse. I am adding another wire next to it like a double curtain rod and then attaching a wire at the peak of the green house. I can draw the sides shut the draw the second curtain shut and lift up the bottom and clothes pin it to the top wire.

For my low tunnels I ripped 2×4 into 3-4 sections about 1/2 inch thick and then cut into 18″ long sections drilled a small hole in one end through the flat part. Screwed them on to the sides of my planting beds so that they will rotate upwards. If the hole is a few inches up from the bottom and you screw it onto the planter box in the correct place you can just step on that short part flipping up the long part the short part sticks into the ground now you have an instant frame to drape over your plants. Just throw over a cover of sorts (what ever is needed) and poof you are done. When the cover is no longer needed take it off the frame and just tap the frame flat to the ground. Poof its stored easy up easy down. Best of all it’s already attached and stored. I have even used them as tie up supports. Stand the sticks / levers up tie a string from end to end and instant trellis.

Broccoli will take a hard frost and sub-freezing temperatures.

A lot of lettuce will take frost, too. The trick is to let it thaw before picking to avoid wilting.

I built a couple tunnels over our 3 x 12 raised beds. One has 3/4″ polypipe hoops on 2 foot centers and the other uses 3/4″ emt conduit , bent into 3 1/2′ high x 3′ wide square hoops on 3 foot centers. It has a 2×4 fastened down the center with pipe clamps and is covered with 6mil poly with the long edges stapled to a 2×2 so it is simple to roll up one or both sides as needed. If you have a conduit bender, this method is easier and less bulky then a wood frame. We also have a 12x 24 hoophouse made with 1″ PVC conduit on 2 foot centers .Amazingly, it has withstood 18″ of snow on a couple occasions. Also , one issue we had with coldframes was leaving them closed because we expected a cold overcast day only to have the sun come out while we were away and returning home to find steamed veggies in our frames. Coldframes make great solar ovens if you don’t vent them ! We fixed this by installing automatic greenhouse vent openers. They use a wax filled cylinder that expands as it is exposed to heat so uses no electricity . We use a light weight version that will lift a 35 lb. lid. No problem with our polycarbonate lids.

wait a sec I did listen to this podcast I loved it, Cause I’m up in Canada where is cold like a Id swear here …

this podcast interested me. really needed to listen to it. thank you!

i thought this was the steven harris podcast link. sorry

Jack,

Once again you have a show that is eerily timed just as I’m getting ready to construct a 15×15 greenhouse in my backyard.

You gave me a great idea to finance this venture. I’ll go to the farmers market this year and pawn off several heirloom tomato plants that I’ll be able to start early.

Thanks again.

Great show jack, keep the gardening shows coming! Thanks again brother.

As you mentioned in your opener. You have to eat everyday. I think you could podcast one day a week on gardening. And given the seasons, keep it fresh and topical. So +1 for continued gardening episodes.

I have been learning how to use a green house seriously for the last 18 months in this travel I have a few things to add to jacks Ideas. On a small poly green house with a non green house film thorw it away after the season it doesn’t last long with out the uv stableizers and the last thing you want is to have it fail mid season after you put all the hard work and time into your plants. use the frame that is left to hold chicken wire. This will help keep out squirels and cats and other unwanted critters.
Everyone says to buy the widest green house you can afford. you have more area in the middle that is not as cold as the edges and you can always add to the length as your budget allows. I had listened to the family garden doctor talk to the guy from northerngreenhouse.com he had talked about useing poly barrels painted black and filled with soil as his solar battery. then grew warm season crops in them that like warm roots like tomatoes.
venting is so important even in the cold of winter it can get hot during the day so plan to add a fan or have ridge venting.
My green house ( zone 5 ) is a 12 by 24 poly tunnel with 4, 275 gallon ibc totes on the north side painted black filled with water, one is a aquaponic system. the main bed is 3 foot by 20 square foot garden style. I grow vertaily on the north side of the bed I have grown more in this area than my outside garden. runner beans don’t pollenate well till you get bees into the green house so use other types of beans to get better results. In November I added a propane live stock heater in a 2 by 4 horse tank to add extra heat battery. Late November I added a low tunnel over my bed inside the green house then I added two lights total 100 watts thermostaty controled to come on at 40. The lights uselly come on at dark after I losse my solar heat. I have cellery,radish , cabbage, swiss chard, rosemary, carrots, leeks, brocilli, dill, and a few other plants growing in there after we had several night in the -6 range and single digits for about 12 nights I had peppers on the vines till the really cold weather hit. It got down to 23 under the low tunnel during the coldest nights. My main goal was just to extend my season and I think I will be able to winter over some of my vegs. what ever survies will be used for seed next year.
Good luck and try new things:)

Jack,

Great show. (Ironically I listened to it as I was setting up 55gallon barrels as heat sinks in this year’s greenhouse experiment, and you we spot on.)
Last year I did low tunnels with pvc and contractors plastic over cool weather greens. It worked well from a protection/incubation standpoint, but by the end of the season I had tired of the constant covering/uncovering/venting/sealing necessary to maintain the right band of temperatures.
I found the sealed low tunnels to be volatile to temperature swings; left sealed on a sunny but cool day and the inside temperatures were tropical. (Note: I have seen self veting low tunnel plastic @ commercial grower supply houses, but I haven’t tried it due to relative cost).
This wouldn’t be bad if I was trying to keep peppers or tomatoes or non-hardy herbs going, but I was growing lettuce, spinach, chard and similar. Also, the condensation inside the tarp attracted a lot of dirt as the tarps were rolled on and off dozen of times; I always had mud on my hands to some degree after messing with them. Because of the relative opacity of the 6mil whitish plastic I tried to remove it when I had any string of “favorable temperature” days and nights. The food was fantastic and I was sold on the idea, but by March I was planning on better solution for this winter.

This year I decided to pursue a high pvc tunnel over 3 long beds in the back of my garden. (Details are here: http://cohutt.com/tag/high-tunnel/)
Observations:
A higher roof and larger volume is an advantage in managing temperature swing vs the low tunnels. Your extra volume from the raised foundation will be a +.
I highly recommend using greenhouse poly vs contactors plastic. It is thinner, more flexible and has higher light transmission properties. Additionally, it looks better from both the inside and outside. I purchased the 1 year poly from greenhousemegastore in the 24’ width and will have 3 or 4 years worth of covering for about $100. I didn’t opt for the multi year covering since this is all still in the experimental stage and I will undoubtedly reconfigure to some degree after this season’s lessons are learned.
1” PVC cross braced is very sturdy once the poly is stretched over it. Amazingly so.
Self venting is mandatory, at least a partial self venting solution. I have one high window operated by an auto opening cylinder; it mediates the temps on sunny days but…. (see next point)
Cross ventilation of some sort is needed for sunny milder days. A sunny day in the 60s here pushed the temperatures into the low 90s inside the tunnel, even with the vented window. This is good, right? Not necessarily….. (see next point)
Brassicias and lettuce will bolt quickly if the nights are near freezing and the temperatures in the greenhouse hit the 80s/90s for more than a few days. This was a surprise I missed this year- the damn thing worked TOO well and my beautiful broccoli bolted to flowers rapidly- much faster than spring planted broccoli had (this shouldn’t be an issue in the fall by I created to perfect conditions for it. Lettuce acts the same way- it turns stalky relatively quickly and bolts. This is the bad news- the good news you can have two cycles of brassicias in the fall winter- one normal fall planting uncovered and a later winter planting covered.
Humidity: more humid air is a good thing in general and watering is minimal. Unfortunately, this warmer humid environment is nirvana for some of the pests that managed to fund their way in. Cabbage worms went from 0 to 1000 it seems overnight (BT took care of them quickly). Slugs have rediscovered my chard and bok choi and will have to be dealt with.
Winter seeds: I put a flat of lettuce seeds out a few days ago to replace the bolting patch and germination has been very fast and consistent, better than anything I have tried in the past.
Soil temp and plant growth: The garlic, spinach and chard inside the tunnel is all much larger than the same outside- planted at the same time. The warmer soil is the key I believe.
Double coverage: For my low tunnels, I pulled a tarp over the double layer on the colder nights. It made a significant difference on the inside temps and the condensation didn’t freeze @ temps of 16 with a single halogen shop light underneath. I can’t do that with this setup, but I can get double coverage on the beds by using row covers over the individual beds. I picked this and much more up from a homesteader/blogger in Michigan who has had success with poly-covered greenhouses that have no special sources of heat. ( http://fastgrowtheweeds.com/greenhouses/ ) I haven‘t needed it in N GA yet, but my tender lettuce seedling with likely go in the ground in early January and will be @ risk for cold damage if I don’t. (Check out her outdoor masonry oven posts too- excellent).

I could ramble on. It I a whole new ballgame and like my previous expansions, I am having to learn the tricks as I go. Bottom line I highly recommend it.

Thanks for what you do, I hope these snippets help.

Carpus,
Combining the heat sink thermal mass with a cold sink might enhance your plan. A cold sink being a trench or trenches 3 ft lower than your beds for colder air to settle into. mother Earth news had a basic design illustrating this concept.

When setting up our greenhouse for the winter, we put down a thick layer of newspapers and paper sacks first to help with ground heat loss, covered it all with a tarp, then put our Springhouse greenhouse on top of it. We also used a 35 gallon black trash can filled with water as a heat sink. I think we probably need at least one more. The only thing I have in there right now is some pepper plants I was trying to overwinter. Your podcasts have inspired me to try other things as well, though. Thanks.