BioStar Premium Cold Frame
This BioStar 1500 Premium Cold Frame is a great alternative to a permanent greenhouse if space or complexities are a concern. The unusually thick panels are identical to those used in full sized greenhouses. These panels retain heat far better than glass and are stronger. If it's only an 8-9 month growing season that you care about and you want to clear some space for winter, this cold frame dismantles in five minutes for storage until next year.
In many US climatic regions this unit sustains enough warmth to grow vegetables all year round. In the northern climates, you can normally jump start the spring by starting in February and extending the growing season into October. Interestingly, in the winter months, you can experiment with setting a few large cans of water inside the unit to absorb the suns warmth. The retained heat will radiate out overnight and keep frost and light freezes from harming the plants. In the summer months, the automatic lid opener will expand to release hot air and contract again in the evening.
Whether it's a condo garden on a rooftop, deck or patio, or used in a typical yard, this cold frame provides a safe protected area free of birds, pests, pets, slugs and snails. On a deck or patio, simply use standard planting pots for your vegetables and flowers, in a yard use the ground itself with compost added to amend the soil.
I've had this for 3 or 4 years now and love it. I use it to start my tomato, pepper and sweet potato slips in. If they are calling for a freeze I fill a couple of gallon jugs with hot water and place inside, toss a old blanket over the top. I may not need to, but feel "better safe than sorry". It sure beats packing all those trays back inside at night. My husband mounts mine on a sheet of plywood in the spring. When I had it just on the ground the mice or rats tunneled under it and made it their home. Then when the plants come out he takes it down and it is boxed and put back in the shed until next year.
Cold frame has worked out great. Easy to put together and has already had to withstand high winds and snow. Root vegetables planted about 2 months earlier than usual.