Bad Day

I recently completed my greenhouse (10' x 12') and decided to put some of my plants out there because I'm running out of room in the house. Plants that I put out there are Cabbage, Romanesco Broccoli, Cauliflower, and some Zinnias. Well, I've been having a nightmare with this thing since I got it completed.

-First off, I am having troubles keeping the temps down in there. It has been getting up to 100' sometimes up to 115' F in there and so I open the door and try to get the heat out. Somehow I've got to figure a way to put some kind of vent on it. I went out the other day and it said 116 on the therm and my cabbage and broccoli were wilted down bad so I opened the door to get a breeze in which seemed to help.

Now its getting under freezing at night the past night or two and I went back out there this morning and the Zinnias were almost all dead, out of 36 maybe 4 looked like they survived. I don't know if this is because it got so hot in there for a while of because of the cold last night, but I would have thought my cabbage, broccoli, and cauliflower would have died from the heat before anything else being they are cool weather crops.

Kind of a rant, but definitely frustrating.

Also, I had posted this in the wrong area before, going to delete that post. Sorry

I have zero advice, but it sounds like you could use a I hope you can get things figured out.

I'll add a hug. What kind of greenhouse is it?

There is a vent that can be put into greenhouse structures and even hoop houses at places like Lowe's and Home Dept. It automatically opens when the greenhouse reaches a set temperature. I think it was very reasonably priced, too. You'll have to visit and ask. Easily put in. Saw it on youtube one day. If I find the video, I'll come back and post it for youl

Found it. I thought it was Gardenfork and it was. Try this for more info...

http://www.gardenfork.tv/cold-frame-hoop-house-plans-and-update

He states they have them at Lowe's and Home Depot. You can see one online if you click on his info, Charlie'sgreenhousesupply or something like that. I didn't get the URL, sorry. They have them for 19.99.

Quiltbea: Thanks for the info. I'll have to check into that soon.



Martha: The greenhouse is homemade- I construced it out of 2x4s we had laying around from an old project and also used 6mil plastic doubled over. We built it onto the back of our existing garden shed(a 16' x 16') and it is 10'x12' and huge. After all was said and done I think it maybe cost about $50 to complete and that was about $25 for the plastic and some money for screws and staples, lathe, and 3 pressure treated 2x4s for the base. It was an awesome project and hopefully I can get the thing vented properly and really increase my production. Also, I know I haven't posted any pics of anything yet but I'm hoping to get pics of the greenhouse and some SFG boxes I have built.



Thanks for the responses.

Does anybody think the cold snap killed the plants, or is it more likely they died because it got too hot in there?

Hi there
I have those vents in my greenhouse and they work like a charm, thus far.
It gets terribly hot in there and the vents just open up
I am sure whoever invented them must be right, or at least i hope they are...

laufenberga wrote:Does anybody think the cold snap killed the plants, or is it more likely they died because it got too hot in there?

You mentioned the temps during the day which you said were definitely excessive and you were trying to combat that - do you know how cold it gets at night inside the greenhouse?

PS - I am sorry you are having such issues with your plants....what a bummer!

My therm that I have in there records the lows and and highs and I believe it said it had gotten as low as 32'F at night and up to 100 during the day before I got to opening everything up.

Now my broccoli and cabbages are starting to be tipped over as well and I think its too late to start them over so I guess I'll have to wait and see if they stand back up.

Understand that greenhouses, hoop houses, and cold frames simulate the interior of a car. On a cold, sunny day with two feet of snow on the ground, when you open the car door, you get hit with a blast of hot air. Whenever the sun is shining, greenhouses, hoop houses, and cold frames must be ventilated. For a greenhouse, cross-ventilation would be best. Using a fan may be necessary, to either pull in cooler air or push out warm air. It will take some experimenting to figure out what works best for you.

On the other hand, on a cold day with no sun, your car will be just as cold inside as it is outside. Additional heat may be required at night. You could do it passively, by putting dense materials in your greenhouse like big rocks or concrete that will absorb heat during the day, and release it at night. Some folks have success with water containers painted black. Sometimes a layer of cloth or plastic atop your plants within the greenhouse at night will help. Otherwise, a heat source may be needed to get you by until spring really arrives. A space heater will help keep the chill off. I'm having good success with soil heating cables.

Don't give up on your plants. They may well stand up when it gets warmer. Brassicas will sometimes develop a 'dog leg'. They will still become mature healthy plants. It's just that the stem is not strong enough early on to support the weight of the foliage. I've had good luck getting them to stand up by transplanting deeper, or, piling up soil around the stem up to the first true leaves.

Thanks for the responses, a lot of good advice. I ordered one of those vents to put in on one end, and on the other end which is connected to the garden shed, I have cut a 1x1 foot hole which I leave open and the door to the shed and a breeze seems to get through. I think I might try to plant my plants in deeper containers and bury the stems with dirt up to the first set of leaves, I hope this helps. Also, I will try to snap a few pics this afternoon before work and hopefully get them posted after work tonight for anybody that is curious. Once again, thanks for the responses, being such a newbie is stressful

You're lucky that most cole/brassicas like to be buried a bit deeper when transplanting, like broccoli about an inch, and cabbages up to their bottom leaves. Many plants won't stand for it. You might manage to save some of them. Good luck.

My new greenhouse has vents in the roof and you can buy automatic
openers. I'm sure it wouldn't be that hard to make vents you could
connect them to.

Greenhouse Window Vent Opener

Green House, attached to garden shed:



Zinnias:



Bad Broccoli/Cabbage/Cauliflower:



And again, another tray:

Were they in here when they were starting to sprout, because they look like they are stretched out to look for light and only have their first baby leaves. Poor babies!

No, they were in my basement under a grow light. Unfortunately I have never used a grow light before and I realized after a few days that I had it too far away from the plants. I readjusted it and I'm not sure it mattered. I think they are all doomed.