veggies in greenhouse in winter like the 4 season gardener

Seattle, WA


My greenhouse is in zone5, Rocky mountain area at 6,500 feet. I have only solar heat and am growing vegetables planted in Mid November. I realize now these plants should have been planted in September to attain mature growth, but am so pleased to have them growing.

I really like the idea of growing year round in the greenhouse with no external heat source and am almost amazed that I can actually do this when a snow storm is raging outside.

Are there any other gardeners who are doing this presently? I'd like to correspond as to any other information I can acquire to do this in the future. I already have learned about Aug-Sept. planting and mainly want to grow salad crops for the winter in raised beds with FRC covers.

Gene so

Monroe, WI(Zone 4b)

I wanted to grow some tomatoes in mine, but neglected to take up some of my plants from the garden before freezing. My g'house is heated. Maybe I should start some seeds.

Ahhh- it's time to start thinking about seeds and I was wondering about growing spinach and lettuce in my little heated hobby GH. I was wondering if anyone's grown these in a GH. I can give them some supplemental light since our winters tend to be a little gray here. Any successes/failures out there? Not wanting to get into hydroponics at this point so the plants would be growing in pots/containers.

Olean, MO

I am new to dg but have been growing in a 20 x 20 hoop house following elliot's ideas for three years now. I love it! have 2 raised beds that are concrete block construction 1st year just tried one bed of leaf lettuce. this year i have 1 of the beds in lettuce and spinach way too much for a family of three we pick every other day. other bed is in brussel sprouts, kolrabi, and broccoli. because of the 65 degree days in december and january it has been weird. i forgot to cover the brasicias and lost my one inch buds on the broccoli. but hopefully will get side shoots.
what are you growing?


I did manage to start some long-standing spinach and two varieties of leaf lettuce - 'Tango' and 'Asian Red'. 'Tango' came up in about 4 to 5 days and is about an inch tall but 'Asian Red' is still struggling a bit. I do have half a dozen spinach seedlings so far. All planted on 1/7. That's about all I'll have room for in my little GH.

Deep East Texas, TX(Zone 8a)

I am in a bit warmer climate here than most of you and we have also had a milder winter this far but I'm trying somethings in the GH this winter for the first time.

My idea was to grow salad fixings. The lettuce and greens immediately seemed to be a magnet for white flies. I promptly moved them out.

I wanted cucumbers and chose a parthenocarpic, smaller type. They are planted in a large pot with a tomato tower for them to grow on. I'd have to look back and see if I marked when I planted them. At any rate, we harvested the first cukes this week. They are small but taste excellent in January.

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Deep East Texas, TX(Zone 8a)

I've found these potted vegetables require lots of water, particularly as they have grown larger.

I also used an organic fertilizer that sprouted fruit flies which irritated me till they died off.

For a tomato, I chose a small currant tomato. The plants have grown beyond my expectations. They are a sprawling 4 to 5 feet tall.

When they started blooming, I would shake the plants to pollinate the blooms.
They are loaded with small ripening tomatoes that have a large burst of tomato taste.

It is hard not to nibble and graze while out working in the GH.

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podster - those look great! I don't think my little hobby GH is warm enough for those though. And our cloudy, gray winters means a lot of plants have to go under lights. I'm also having a problem with fungus gnats/fruit flies and I think the potting soil might be the problem as well. Thank goodness for yellow sticky traps.

Deep East Texas, TX(Zone 8a)

Thanks Cindy ~ mine drops to the high 30s/low 40s but usually runs from mid 50s upward.

The greenhouse stays 10 warmer than outdoors and when heated, I can keep it about 20 warmer than outside.

I need to purchase some yellow sticky traps and never think about it till I need them. Where do you find them? Kristi

Wow - I assumed your GH was warmer than that for the veggies, especially tomatoes. On really cold days/nights, the temp drops to 50 to 55 in mine. Daytime temps depend on how sunny or windy it is outdoors. As for where to get the sticky traps, I bought them online (easier than running around locally trying to find some - OK, label me as lazy). Amazon or lots of other garden supply companies carry them. I even saw a link to making your own but didn't look at the requirements/process. They're supposed to work well with aphids (which I see very few of on a sticky trap) but work better with fungus gnats/fruit flies. I tried cider vinegar traps but haven't caught a single one with that method.

Bardstown, KY(Zone 6a)

"the temp drops to 50 to 55 in mine"

Dang Cindy what are your heating with? I feel lucky if I can keep mine above 40. I have an oil-filled radiator heater with a thermostat on it. But of course mine is a lean-to type so only three sides have glass along with a bubble wrap insulated polycarbonate roof. I don't really try to grow anything in there this early anyway just keep some tender plants alive for the winter.


Doug - (chuckle) I have a 6 x 10 hobby lean-to GH with the double polycarbonate panels. It's attached to the south wall of our attached garage (which is also heated). DH built a wonderful door for me so that I can go right from the house, through the garage and into the GH. At first, I was using little electric heaters to heat the GH space but that was rather expensive. Then I tried a propane heater with the tanks sitting outdoors with hoses running through the lower GH vent into the GH to the heater. Awkward. And I had to go outdoors to turn the tanks on or off. DH installed a non-vented natural gas wall heater with a built-in thermostat on the garage wall in the GH. It has reliable air sensors but makes heating the GH pretty simple. I also use bubble wrap indoors on the roof panels and on all of the wall panels with rigid styrofoam all around the lower 3 ft. I also add the foil backed bubble wrap on the two ends for extra protection. I don't lose much light from them in the winter months and it helps protect against the cold winds from the west. While I start most of my seeds indoors, I do a lot of cuttings and non-hardy plants in the GH (not enough good winter light in the house). If it warms up too much in the GH, I open the door to the garage and let the heat help keep the garage warm. Also works conversely - warm garage air into the GH on really cold days.

Deep East Texas, TX(Zone 8a)

Cindy ~ interesting to hear how you have weatherproofed and heat your greenhouse. I would think one of the big heat savings is the wall panels with rigid styrofoam all around the lower 3 ft. A lot of cold air enters at ground level.

Doug ~ what temps does yours average and what size is your greenhouse?

I use a small wood burning heater and when it burns down, an electric convection heater that is thermostat controlled kicks in. It will cycle on and off as needed. I have not found it to cause a major increase in the electric bill but maybe that is because I'm used to paying more when we use a/c all summer long.

Cindy ~ I might be wrong but find tomatoes do better in cooler temps than in hot ones. When planted outdoors in summer, they will quit pollinating when the nighttime temps get too hot. We have a spring and fall planting season and it is pure misery to try to keep a tomato plant alive till the weather cools in the fall. The tomato plants growing right now are located in the coolest end of the GH. I put them there as they will receive the strongest winter sun there too. I just have to remember to shake the vines when I walk by to keep the blooms pollinating.

Bardstown, KY(Zone 6a)

When we had temps in the upper teens/lower twenties with wind chills in the lower single digit range it only dropped to about 40-42 degrees in there so I can live with that. I have the thermostat on the radiator heater set to kick on when it drops below 55 degrees. It's been averaging in the 60's and 70's in there during the day, but we've had a very mild winter so far. The greenhouse is about 11 X 8.5. Wish I'd thought to insulate under the floor when building it, that would have made a huge difference I think. One of the issues when living on ground that is not flat!! I still wouldn't give it up though. I love my hillside garden.


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Bardstown, KY(Zone 6a)

This was in June of 2010 a little less than a year after I completed it.

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podster - amazing fact about the tomatoes being able to take cooler weather. Even here in the summer 90s, the tomatoes will stop blooming. I did try growing tomatoes in the GH one summer (since all of the other plants had moved out). With a drip irrigation system, 2 fans and 2 roof vents for ventilation, 5-gallon buckets of good potting soil along with amendments and mild fertilizer, they grew tall but spider mites kept them rather scrawny. Not enough room in there to grow tomatoes in the winter though. That's where all of the tropicals stay over winter.
I do try to insulate well around the bottom of the GH since mine was a kit and I know there's leaks where the cold wind can come in. Wish I would have thought to put rigid insulation under the gravel floor that I have as Doug mentioned.
Doug - you're so right about having a mild winter so far. And I do think you've got a beautiful hillside garden! Mine slopes away in the back where the construction backfill just stopped. It's tough on the legs and ankles when gardening but I like the interesting topography.

Deep East Texas, TX(Zone 8a)

Nice and neat looking greenhouse Doug. It may not be as good as insulating the floor but you could skirt the bottom of the GH to help perhaps.

The floor in mine is concrete so I don't let potted plants sit directly on it as it retains cold.

Cindy, sounds like the GH is never quite large enough. Even bigger would be full. I keep saying I'm going to narrow it down but haven't managed yet and still adding plants.

My greenhouse gets so hot in summer (positioned wrong) that all the plants have to move out. Any plants left in there would be toast. I have two retractable clotheslines in there in summer. When hot and dry, I can dry up to three loads of clothes in a day. No bird poo, no bugs, rain is not a problem.

Bardstown, KY(Zone 6a)

I do have skirting around it. Leftover T-111 siding. I have a family acquaintance who does insulation. He said he come down some Sunday and drill a few holes in the floor and shoot insulation down into the area. That should help tremendously.


Deep East Texas, TX(Zone 8a)

I'm sorry, I didn't notice the skirting in your second photo I was so taken with how attractive your greenhouse was. The open space under the floor in your first photo was what was on my mind ~ my apologies.

Good for you on the insulation installation. Not wishing bad weather on you but hope you will find it helps the greenhouse temperatures.

Now if I could cool my down easily in summertime...

Podster - I remember you mentioning using your GH in summer for drying laundry in another thread. I still think that's a brilliant idea! I don't even try to grow stuff in the GH in the summer anymore. I do have shade cloth that goes up in the summer on the inside of the roof so I can do potting up in their without melting but it's still hot.
Doug - you lucky thing - having someone who can insulate your GH.

Deep East Texas, TX(Zone 8a)

Yes, I use shadecloth inside too. But I don't know what percent it is and have recently read that green shadecloth may be better than the beige I have.

I'd never have thought of the shade cloth color making that much difference. Kinda like the differences in the color of plastic sheet mulch on vegetable beds? I have a dark green shade cloth but I didn't use it when I tried to grow tomatoes in the GH, thinking that the plants needed all of the sun they could get. Perhaps a mistake?

Deep East Texas, TX(Zone 8a)

I don't know.... I would have thought the darker would make it hotter too. I will have to remember where I read that useless fact. lol

Bardstown, KY(Zone 6a)

Well I'm seriously thinking about buying some shade cloth in case we have another very hot summer to stretch out over my tomatoes planted outdoors to diffuse some of the scorching/splitting problems from last year.


What a brilliant idea! Do you have a full-sun veggie garden? From your posted photos, I remember that you have a lot of trees. Would the white row cover work as well? My shade cloth is pretty hefty in weight (it's about 10 x 6 ft). I remember seeing an organic farmer down in TN using a shade cloth over a long arbor to grow more sensitive things underneath but now can't remember if it was row cover or shade cloth since I couldn't get close enough to see.

Bardstown, KY(Zone 6a)

Well since we live on a sloping lot I had to make a raised bed plus I grow all my tomatoes in strawbales now, but yes it gets sun just about all day. I think anything to cut back on the heat would help the maters since they quit blossoming when it get above 85 or 90 degrees anyway. I'm gonna try it this year and just test the theory.


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Very nice setup you have there. Have you ever seen those "sail cloth" sun shades on tv? I'm wondering if you couldn't put up 4 posts, one in each corner of your garden area and tie a "sail" to the posts. It would give more "moving" shade and might also make it more comfortable for you while you're working in the garden. Great idea with the hay bales. Will have to remember that one.

Olean, MO

Hi all
Wow I am really surprised at how many of you heat your greenhouses
Being in zone 5b I have never tried to heat, did use 5 gal buckets one year didn't help much and found that i didn't need them. but i won't try tomatoes, cuz i know it wont work. cherries that i took off deck lasted till Dec 12. which is better than the ones outside did.

Deep East Texas, TX(Zone 8a)

Daddave ~ What do you grow in your greenhouse?

I can't speak for anyone else but most of my GH plants are tropicals and succulents just cuz I like them. lol

My seed starting is done outdoors in jugs ala' wintersowing and the vegies are grown outside also.

This is my first try at winter vegies in the greenhouse and I'm o.k. with the types I've chosen but I won't be throwing out the tropicals.

BTW, I also have a lemon, a lime and a satsuma tree in the GH.

I hope we haven't lost Geneso after the first post of this thread.

Olean, MO


Look at my post on Jan 17 2012 mainly just food at this time.
I also overwinter my potted mums which i will start to take cuttings from on about march 1 to grow for fall sales.

Deep East Texas, TX(Zone 8a)

Dave ~ I just reread your post and it strikes me how diverse we all are.
I grow some of those plants you mentioned outside in the ground all winter here.
I'm growing a few varieties of lettuce, chard, arugula, onions and parsley.
Many other gardeners in this zone grow cauliflower, broccoli, cabbage, etc through our winters.
Very interesting, isn't it? 8 )

daddave - I do envy all of the space you have in the hoop houses. I had read in 2011 how a lot of the CSAs up here in the north (especially MI) grow up into the end of the calendar year using hoop houses to extend their season. Not sure if the growers heat them or not. And then they start early in the spring, guessing with lettuces and cool weather crops. I've also seen partitions being used so that a portion of the hoop house can be heated without breaking the bank.

Olean, MO

in my opinion heat is just too expensive, when i go out to the hoop house on even a cloudy day, i can put my hand under the inner cover and it will be abt 50 to 60 degrees when it is about 20 outside. that is what works for me.

Nice to have that kind of solar gain! It sounds perfect for growing veggies. Do you get any of the really frigid weather down there? If it's close to zero here with a wind chill (leaks in my GH) and cloudy, I don't think some of my plants would survive.

Olean, MO

last year had several nights -5 and 1 night -9
lettuce still made it.

Yikes! I never thought of MO as getting quite that cold.
I saw an Elliot Coleman book over at a blog this morning (Not Dabbling in Normal) - A Winter Harvest Handbook - using organic methods and unheated greenhouses. Wish I had the open space to do a hoop house but I'm on a wooded lot in the 'burbs.

Olean, MO

Quote from CindyMzone5 :

Elliot Coleman book over at a blog this morning (Not Dabbling in Normal) - A Winter Harvest Handbook - using organic methods and unheated greenhouses. Wish I had the open space to do a hoop house but I'm on a wooded lot in the 'burbs.

The first time i tried his methods, I set up a test bed 2x6 planted then I used painters plastic drop cloth's first hoop or cover was 18" high second hoop was 3' high over the smaller one. I live in Missouri the "show me" state 8-) )) It worked but had to be almost dismantled to pick lettuce.

Your initial small hoop area does seem to be a manageable size but I my only space free of overhanging trees is on the side of our pie-shaped lot. I did clear out some perennials last fall to try a few veggies in the ground this year - tomatoes, summer squash and cucumbers. I might be able to do a tiny hooped area in that spot if all goes well. I'm thinking it would be more like kale or hardier cold-crops.

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