I recently built a cold frame - 3 ft by 6ft - insulation and wood on the outside - sliding glass door top - 18in. tall at the bottom - 30in. tall at the top. I'm not sure how to use it. I live in PA with a last freeze date of May 10th. I have cucumbers and squash in there now but there getting spots on them. I'm confused as to when to keep the lip open and when to keep shut. I think my plants have spots from mold or mildew? Appreciate any help.

Hey Andy,
I just built a cold frame this year too. The idea, as you probably know, is to use it to gradualy harden off your plants to get used to the weather. The door should be slowly opened over days (maybe weeks) letting the environment in. If you open the door completely and then close it completely every day you may be burning and then shocking you plants.
Hey guys, help me out here. Anyone else have any theories on this?
- Bada

when i used a cold frame i would open it on sunny days, to keep the temperature form cooking the plants. as the sun went down i would close it to retain the heat built up form the day light hours. make sure that you are not watering the plants too much, and if you must water, water earlier rather then later. a cold frame is like a minature greenhouse and you need to adust the temperature to allow ideal growing conditions for your plants. over heating is more of a problem this time of year then cold is to your plants, so as the days warm up longer, keep the lid to your cold frame opened for longer period of time. the closer you get to your frost free date, begin to leave the lid off your cold frame until you reach frost free day and remove the lid for a few days and then transplant your plants. hope this makes senses and peace be with you and may your garden grow.

I have been using cold frames for years and years.

Put a thermometer in yours, if the temps get above 750F than open the window. If it is sunny and above 500F you should crack the window at the very least. If the outside temps are above 650F than open the window all the way for the day.

You have somne heat loving plants that should not be subjected to temps below 550F at night and I am sure that you have had temps close to freezing (or below) that will hurt your warm loving seedlings. If you have a heater in the CF, great if not you may want to bring the babies in when night temps go below 400F.

I am a bit concerned at how early you started the cukes and squash. They will be HUGE by your transplant date. I usually start such items about 10 to 15 days before I want to transplant them. So you may want to trash this bunch and start over again.

Well hello... I live just down the road a piece ,south of Gettysburg... We just had a shed raising last weekend down next to my garden. My next plan is to add a cold frame on one side of the shed... I have been looking in catalogs and they make an automatic opener that works off of tempature so you do not need a power source. I do not know if they work on any frame or just the frames from the catalogs...since I am planning on ordering a ready made cold frame I thought I would get the automactic opener... my garden is a ways from the house and I am not home all day to monitor tempatures...If anyone has used one of these I would like to know if it is worth the money...

Welcome, newgrdener. We ordered a ready-made about 7 years ago from Mellinger's Nursery Catalog. Had automatic opener. Worked great for about three years, then pooped out! :-(

But, by that time we were ready for a greenhouse. That's usually the route....beware! ] Once you get bitten by the "cold frame" bug....sooner or later you're gonna want something bigger!

Automatic openers that are sold separately can be used with your own ready made cold frame.
Charley's Greenhouse & Gardens sell lots and at a good price:

http://www.charleysgreenhouse.com

gardenz