Sure. I keep my greenhouse full of many things year around, and nothing is tropical. I start perennial cuttings, seeds, hold geraniums in it through the winter so that they dont freeze. Today I just put in some new potted grape cuttings to try to encourage them to begin growth/rooting sooner than sitting outside. I do have electricity in my greenhouse for an attic fan for the hot summer, and for a small heater for the winter. My objective is to keep the inside from freezing, and it does that. Most plants I grow can go right down to 34 with no problem.

Is there anything that can benefit from growing in a greenhouse even when it gets warm enough that they really do not need it. This will only be used for vegetables. Say like watermelons, they like it hot and I live in MI. so would they benefit from a warm greenhouse in the summer as long as I had a fan so it would not get to hot? The reason that I am asking is I have the opportunity to get a 25x50 greenhouse but I do not want to get crazy and heat it all winter but I would like to get a longer growing season. But then again I do not want to take up a lot of room in my yard if I cannot grow things in it all summer.

Dale

Dale

If you're not going to heat it it may not pay to have it. A GH will be maybe 1 or 2 degrees above the outside temperature. If you want to start tender seeds you still have to do it in your house. You can't put them in an unheated GH until after frost in your area. In summer you'll need to find a way to cool it or your plants will overheat.

thepodpiper,

Don't think greenhouse, think another 1250 sqft added to your living space.

There are no rules here that you have to grow something in it all the time. Think of it as a structure.

What you have to consider is the initial cost, the replacement covering costs and the use you can get out of it all year round.

Mine is unheated (O.K. I cheat a bit) but it is used all year. That is why currently I have so much non-plant junk in there that I have to seriously try to clean it out to make space for plants.

If you have kids it would make a great playroom during the winter on a sunny day.

Yep I am nuts.... My greenhouse has internet access. but no proper water or electric supply!

It is just nice to sit out there in the sunshine and be warm in the dead of winter.

The early start for plants has become a secondary use for it.

Hi
Can't help you with your questions but I'm curious as to what a 25x50 GH would cost. Would assume you'd need a foundation below frost line in your area.??
Have you checked into the costs of this even if you got the GH for free. lol
25x50 would cover my whole lot lol gary

It's not a permanent structure so I do not believe you need a rat wall. To me it's not a cost thing it's more of a is it practical for what i am doing thing. All I want to do is grow vegetables and if this would be a benefit to growing them in my area instead of a big building taking up garden space I might proceed further but from what i am getting from other forums I do not think it to be beneficial.

Dale

I don't think it to be beneficial at all. In fact I think you would be causing problems such as inviting an environment for fungus to occur, etc. It just makes absolutely no sense whatsoever.

Dax

Dale, if you were to grow summer cutting crops on a mist system, there's huge potential for it's use. I thought that should be clarified.

Dax

I don't heat my greenhouse and I wouldn't give it up for anything!
I can extend my growing season in the spring by two months without heat.
Just this past weekend my thermal mass (big water tank) just thawed, so it should be just a couple of weeks now before I can start moving my seedlings out to my greenhouse.

I also use my greenhouse all summer to start new things from seed and cuttings. I have a two stage fan setup and also use a mister to keep it from getting too hot during the hottest part of the summer.
Another option for keep the temperature from climbing too high is to use a shade cloth. I'm planning to add this eventually to my greenhouse as well ( I don't have any ceiling vents).

My greenhouse isn't quite as big as the one you are considering but I have considered growing some warmer season crops in it (like watermelon). I just haven't found the space in mine to do that.

I put up a HFGH 6x8 last March and used it during the summer for propagation. I do not heat during the winter so it is basically empty except for some perennial seeds I started. I wish I could have afforded a larger one and currently thinking of buying another one like I have and joining them together. I don't have much room with current GH but I think controlling the heating and cooling would be better with a larger one.

The big plus of having a greenhouse is it also gives you somewhere to escape to for a few hours..with no questions asked :)

I'm a big fan of unheated greenhouses. See my post in the NW gardening forum. But remember that your climate is much colder than the NW. How much do you want to spend on heat? 10x the value of the plants? 100x? If I were in Michigan, I would convert a room in the house to an indoor growing area, with fluorescents or halides. A basement would be perfect. No extra heat is required, and all of the waste heat from the light fixtures goes into heating the house. It is nice to be able to tend to your plants without going outdoors. But you will not be able to spray with toxic stuff, like you could outdoors. One of my indoor seedling starting setups is shown below.

{{gwi:9572}}

I am a believer of a heated a greenhouse, but heating a greenhouse does not mean you have to keep it at 60°F. You might grow something that only needs 40°F etc... Its all up to you and what you want to do with it. The real beauty of these green structures is that you have a place to sneak off to. When I want to disappear from the world, I sneak off to the greenhouse. Only problem, its the first place the kids and wife look when they want to find me.

You can check out my special place at the link. I will be updating it tomorrow with new pictures.

If you plant directly into the soil you can harvest greens all winter in an unheated greenhouse. There's little growth in mine from mid December into February. I harvest what has already grown and is holding. We've been eating tatsoi, kale, lettuces, spinach and beet greens this winter.

Link below. It looks dismal with all the snow after the storm (looks like that this morning too) but inside there's food growing.

I can't imagine that much snow!!! & I'm comlaining about a huge amount of cold rain here. I'm suprised that even your winter greens survive that much cold. That's great. I'll have to try some here next year.

Robin...serious? You have salad greens and beet greens NOW in your unheated greenhouse? When did you plant them???

That's an encouraging thing for me....perhaps a good reason for me to build the greenhouse I want to build this coming year....What about carrots? will they also grow ok in the winter here in Maine?

I have always loved gardening and landscaping at home. I have been contemplating a small greenhouse and if it would benifit me in North Carolina. The only thing I can thing of is I could start tomatoes from seed to sell at our community farmers market. I also intend to propagate lavender. Our last frost is 3rd week in April with maybe one woops in first week in May. To have tomatoes, Pansies, etc ready to market I would have to start seeds maybe in March. Maybe potatoes in raised beds in winter? I dont see the benifit of having a green house in zone 7 in the summer months. Squash maybe with fans blowing? I guess the question should be, how can I justify a greenhouse in zone 7? Any information would be well apprecaited. / Chestnut2

Dale:

I would not want my greenhouse if I did not heat it through the winter. I do move my tomato and pepper plants out there before they are planted out, to have more available space for them, but if I did not use it to keep perennials alive and grow vegetables through the winter, I would have no real need for it.

If you have an "unheated" greenhouse, I think it is going to be hard to get plants started in it. It is going to be the same temperature inside as it is outside, at night. It may be warmer on a sunny day, but plants also have to endure clouds. You might be better off "winter-sowing".

Allow me to cast another vote in favor of unheated greenhouses. We live in Montana, zone 4 and we have very long, very cold winters. (Which is great, I love winter!) Despite that, our unheated greenhouse is useful all but about 8 weeks of the year. The other 44 weeks of the year, we harvest delicious food from our greenhouse.

There are many ways to grow things: in pots, in the ground, under row covers or additional protection. You can grow root crops, salad greens, start seeds, overwinter container plants and do all kinds of things.

Like any greenhouse, one needs to do some experimenting with timing, types of plants and technique. I think of our greenhouse as a large (and tasty) science project. I don't get too hung up on the outcome the first time I try something, but I look forward to learning more and more.

I don't understand how folks with heated greenhouses can say that an unheated greenhouse ain't worth it because it certainly is! It all comes down to your approach and what you want to do.

I live in a very wet, rainy climate (southern Oregon coast)

An unheated greenhouse can easily add two months before and after the regular season. I can have peas, lettuce, broccoli and other cool crops from fall to spring most years.

It also keeps your plants out of the rain so watering and fertilizing is easier.

Make sure to keep one or two oscillating fans on a timer to blow around now and then so strengthen plants.

Hi- This is my first posting on gardenweb.

Karen mt are you still reading this forum? I am curious to hear more about your greenhouse experience. What type of greenhouse do you have? I got to this forum because I am considering buying a greenhouse. I live in Colorado at high altitude, probably zone 4 maybe 3. I wonder what temps the greenhouse will stay compared to outside temps. Do you use some heating to exetend the transitional seasons? Can I at least start growig early and extend into the fall with a greenhouse? I'm considering a Juliana premium that has 10mm polycarbonate siding but it is $2000 more than an easygrow with 6mm siding. Is it worth it to buy the Juliana?

Thanks for any information.

To krustofsky -

In your location and altitude, my guess is that you will love your greenhouse! With our Rocky Mt sunshine in the winter, it is amazing how well things can stay warm. I have a Riga greenhouse, which has 10mm and 8 mm double-wall panels. I chose it because it is very study and has thick panels. I believe the Juliana greenhouses are similarly robust, so I would recommend that over the 6mm panels if you can swing the extra cost.

There are many other steps you can take to insulate your greenhouse. Insulating the outside perimeter helps a lot. We dug a trench 18 inches deep around the perimeter and put 4 inches of styrofoam all around. We also have many 5 gallon buckets painted black and filled with water. I use row covers of various thickness, plus heat mats. Many people use insulated pool covers or bubble wrap in the winter, but we have not gone that route yet. I don't mind having a short break from tending the greenhouse during the coldest part of the winter anyway.

You can learn a lot by searching this forum, and I also recommend two books: The Greenhouse Gardener's Companion and Four Season Harvest.

A note about the price of a greenhouse. One thing I didn't factor into the cost (which was probably a good thing) was the additional expenses related to getting the greenhouse set up. Materials for flooring, edging, shelves, plus electricity and water service (essential), plus shade cloth, fans and a remote thermometer. None of these things breaks the bank all by themselves, but all of it adds up. However I have not one regret. We didn't cut any corners and I am in love with the whole greenhouse experience. The amount of food we produce, plus the satisfaction we get, makes it well worth it.

Someday I will learn how to post pictures here so I can do some show and tell!

Thanks karin mt. That is very helpful information. I assume we will go for it with the greenhouse this spring.

karin mt. I read with interest your posts re your greenhouse. They were very encouraging. I had a small unheated greenhouse house built this past spring. It is 7 by 16 feet. We installed a couple of rainbarrels inside that feed from the downspout. I also had a solar powered exhaust fan installed. So far I absolutely love it! I have so many tomatoes growing in there and they are 8 feet tall! I also have cucumbers that are thriving. My peas are about to flower and I am hopeful they will do well. I live in Wyoming and I know that in cooler zones, a couple of cold windy nights can do a garden in (and people who plant them :)). In our area there were so many grasshoppers that ate away at a lot of gardens this year too. So my greenhouse has already provided me a wonderful summer and fall garden. I am anxious to see how long I can keep it going as winter approaches and how soon I can start again in the spring. I will add additional insulation, and we'll see how it goes. I appreciated your posts.

Hi Loveitgreen,

Your setup sounds great -- and quite similar to ours. WY and MT share similar gardening challenges. You are so right that one cold night can end everything, as happened tragically last year.

Sounds like you have found out that a GH can be great for the summer crops and provide protection from winds, grasshoppers, deer, hail, and all our other assaults on tender plants!

We also have enormous tomatoes and splendid cucumbers right now. (While outside I have had zero ripe tomatoes and 1 ripe cucumber.) In the past, I've been able to keep them going until outside lows go into the teens. For added protection, I pull thick blankets over the plants at night when it is forecast to be cold. As the fall draws on, the plants lose vigor but you can keep them going quite a while.

In the meantime, you can start new seeds of salad greens now. We just had our first harvest of baby mesclun greens last night. I have several more types of greens starting up now and I love the idea that these will feed us right through the fall.

The other rewarding things to grow in fall/winter/early spring are hardy flowers like pansies. Nothing beats some cheerful flower faces to greet you when all is snowy outside.

Enjoy your GH!

-Karin

Dale - I am new to this greenhouse thing as i built mine last year but i am greatly encouraged that not only is an unheated GH useful in the Winter, it is downright astounding!

I had just about covered my GH last October. There were some things left undone. For a lark i planted peas and beets in November and had some small plants by time Winter really set in (Mid December). My peas were about 6 inches high when the cold stopped growth. By mid-January, both started growing again and i harvested fresh beets and peas in march. I also planted peas, carrots, greens, broccoli and more beets in march. Harvested my first broccoli in may. They didn't do well due to the double layer restricting the light with 3 plants producing what one might in full sun... but it was FRESH!. Those that i transplanted outside did much better. The peas i planted in november lasted well into summer and grew to over 11 FEET tall! didn't produce great, but it was fun to watch. The peas i planted in march were the most prolific i have ever had!

My GH is not normal though. I based it on the "Solaroof" concept, basically a greenhouse within a greenhouse. I have 24 inches of airspace on the sides and 32" at the peak. I have a door on one end and the other is 24" air space. My doors are just single layer of plastic.

Above the doors to the peak is my vent. It is just open to the air. I did that thinking i might get away with less fans needed letting the heat naturally rise and vent. I did staple a single sheet of poly at night and took it off during the day. Temps in January still exceeded 90F at times.

I did see some freezing to the crops at night but it always recovered. Whe had several nights below zero. A five gallon pail of water might have 1/4 inch of ice on it but the ground never froze.

Where i have my door, i did staple a single sheet of plastic bridging the the dead air space so it wouldn't get infiltrated with too much air, but it wasn't sealed. I also neglected to seal much of one end. There was plastic there but the wind would get into the dead air space.

The idea behind the solaroof is that the air space gets filled with soapbubbles at night and is allowed to drain during the day. Wasn't much data available on the net as to it's true effectiveness but it made some sense to me. I have not gotten to the soap part... yet!

This year:
- I will have the ends sealed.
- I will add a second layer of plastic on my doors so i have a 2" airspace on the doors.
- I will have 2" foam board that i can use to close the gable vents at night.
- I have a 1500 gallon wire frame fish tank inside the greenhouse to test whether that also helps to moderate temps and to see what types of fish might survive.

Some things i noticed.
- It rains inside the greenhouse! I am hoping once i seal the outside walls, less air infiltration will mean less condensation inside.
- The steel frame gets HOT. I may rig something up to circulate water to the peak and run down the inside of the pipes to an indoor tank conserving heat. I will only do that if the other steps don't moderate night temps.
- Do not start your outside plants too early! I started mine in February/march and in early may the greenhouse temps were so high and the plants were so large that i needed to water twice a day and they would still wilt. Of course, i planted lots of extras and being my first experience, i didn't have the room or pots to put them in 3" pots, so they stayed in the 6-packs. Next year i plant what i will use and transplant into larger pots... maybe start them later too.

All in all, i have been amazed at what survives and grows. I plan to sow all sorts of cool weather things just to see what happens.

Play and have fun.

Poppa

Well, I had originally thought I would pull everything up and let it rest for the winter. I guess I will just let things be in there and see what happens. I still have tomatoes galore. Also, the peas are doing great. Lettuce, onions, and carrots are still doing their thing. So, we will see.

I too hope I will be amazed how what can be done. I saw today I have a little greenhouse guest. A small mouse who seems rather fond of my greenhouse garden. I know he's gotta go but he seems a rather kindred spirit who also loves a warm sun, and things that grow.

Thanks for your response, Karin.

I'm glad this thread went on so long. well I did not get the original 25x50 but I am going to build a high tunnel this year and get rid of my 10x20. I have been searching for plans and came up with some good ones from this site. I am now in the process of making a parts list so i can start scrounging for freebies. I am not able to put enough plants in the small greenhouse for selling, twice that size should hold me over for another year.

{{gwi:289189}}

{{gwi:289190}}

Dale

Update: Temps have been wild this year. I never did get much of the things i listed earlier done. The only ting i did was double layer on the gable ends.

-11F yesterday and the GH finally took a huge hit (Unheated). My orange and lemon trees finally look llike the cold was too much. -2F did curl most of the leaves but they still looked as if they'd come back. Now I am not so sure. Lettuce is still growing. Looked a little wilted after the -11F, but they are pretty darn hardy.

Beets have stopped growing and are fighting to stay alive - not due to the cold but some $%@#%$#! root eating voles. trapped half a dozen and there's still more holes showing up.

Spinnach is the only crop that has not taken any damage. They still are growing slowly and i had my first harvest in early january.

Shallots cam up from seed in the first week of January. Stopped growing for the most part once the night temps fell to the single digits. I expet them to take off again once we stay in the 20s at night.

Peas look worn. They aren't dead but they certainly have looked better. They stopped growing mid-Dec and took off a bit in early January and then stopped @ about 18". I think i will cut them back and let them grow from the roots. Plenty of basal shoots. We just need a bit mor moderating temperatures.

Strawberries have been flowering but the berries turn black right away. Spring, wherefore art thou?

Had a thin layer of ice on the 1500 gallon fish tank. First time all Winter. Very thin and did not completely cover the surface, but still the most i have seen.

The ground is still soft and workable. No frost or freezing. I'm sitting here and thinking i ought to go and shovel snow away from the sides. I can see from my window that the snow is now up to where the sides bend to the roof - about 5 feet. I'm not too excited about hoofing it out there through the snow. The GH is about 500 ft from the house.

Poppa

My Goodness! You all have some very nice houses.

I only have a 8x6 that I have been heating with the oil radiator heaters you buy at HD...It has been a very expensive electric bill, but it works great. The lowest temps I get are in the 40 when below 0, and 50's to 90's above 10 degrees.

I will be putting up a premanent 8x10 one come the spring.
Is there a better,easy and inexpensive way to heat my house once I put it up come spring? I would love idea's.

Thanks so much!

Mike