what is a cold frame

What is a cold frame and how does it work?

At their simplest, cold frames are bottomless boxes that are set over plants in the garden to protect them from adverse weather. They are usually built low to the ground and have a transparent roof to let in light and a hinge for easy access.

What is the difference between a cold frame and greenhouse?

The biggest difference between a cold frame and a greenhouse is that a cold frame does typically use a heat source and might only stand a few feet tall; whereas a greenhouse is a tall structure that has heating and ventilation systems for a year-round controllable climate.

What can be grown in a cold frame?

Using a Cold Frame to Overwinter Plants

Hardy salad leaves from winter lettuce to mizuna to corn salad (lamb's lettuce or mache) can be sown in the frame in late summer and will keep in great condition over winter.

How warm does a cold frame get?

The temperature difference between the inside and outside of the frame is generally not more than 5 to 10 degrees. A mat or blanket may be placed over the frame on cold nights to conserve heat, but this increases temperature by only a few degrees.

Can you start seeds in a cold frame?

The answer is a resounding yes, cold frames for spring seedlings is a great idea. ... With a cold frame, you can start seeds as much as six weeks earlier than you would put them in the ground. You can control the soil content more easily in a cold frame than in an outdoor bed.

Do cold frames need to be airtight?

When its COLD, you want your cold frame to be as air tight as you can get it. That means filling any gaps between the wood or windows. ALSO, it gets super hot in a cold frame when the sun is blazing, even when its not hot outside.

How do you keep a cold frame warm at night?

Use a birdbath heater or a crock pot to warm up a small cold frame, extending your growing season even further. The warm water in this ceramic pot keeps the cold frame warmer on chilly nights.

When should I use a cold frame?

Advantages and disadvantages of cold-frames

Can be used when you don't have enough space for a greenhouse;
You would love to have an early start on the outdoor growing season or extend your crops' life after the summer is over;
You can use it to protect dormant plants until spring comes;
Cheaper than a greenhouse;

Do plastic greenhouses protect from frost?

Yes, sometimes plastic is used for frost protection. For instance, on low garden tunnels, high tunnels, garden cloches and greenhouses. You need to be careful that your plants don't overheat when the temperature goes up, because plastic doesn't breath like garden fabric.

Where do you put a cold frame?

Place your cold frame somewhere sunny and sheltered, so plants and seedlings get as much light and warmth as possible. A patio provides a stable surface; at an allotment, a few flagstones will do the trick. Or position it on top of the soil, using it as a large cloche when sowing or planting directly into the ground.

How do you keep a cold frame warm?

You can keep your cold frame warm at night by adding heat-absorbing materials, improving the frame's insulation, and increasing sun exposure. Cold frames should always face south at a light angle to make the most out of the daytime sunlight.

How deep does a cold frame need to be?

The ideal size for a cold frame is 3 by at least 6 feet, about 12 inches deep along the front sloping to 18 inches at the back. You can build a cold frame out of 1×12 pressure-treated lumber, assembled with nails and screws for permanency or prefabricated corners for easy dismantling and storage.

Will seeds germinate at 60 degrees?

In most cases an interior temperature of 60-70 degrees is not warm enough for quick germination, but seeds usually will germinate eventually (lack of supplemental heat is especially detrimental to peppers and eggplants, both of which are REALLY SLOW to germinate when left at room temperature).

How cold is too cold for seeds?

Daytime temperatures around 60 to 75 degrees Fahrenheit typically mean the soil temperature is between 50 and 65 degrees and perfect for seed germination. If the soil temperature is much lower than 50 degrees, however, the seeds will lay dormant and not germinate.

At what temp do seeds germinate?

Most seeds germinate when the soil temperature is between 68(and 86(F. Once germination occurs, the optimum growing temperature for theseedling is about 10(F cooler than the optimum germination temperature. Moisture is critical for germinating seeds.

Does a cold frame need ventilation?

Ventilation is a top priority when it comes to growing in a cold frame, the daytime temperature can fluctuate dramatically during autumn or spring which means you can easily cook the plants you were trying to protect from the cold!

How effective are cold frames?

Root crops such as carrots and beets can happily remain in-ground in many areas with no more protection than a blanket of leaves, but by placing a cold frame over them the soil remains much drier and softer. This makes them easy to dig up when you need them and reduces the risk of rotting.

What is the difference between a cold frame and a hot bed?

Hot beds and cold frames are identical in construction; the only difference is that hot beds are heated and cold frames are not. Hot beds are generally used to start seeds. Cold frames protect young plants and harden them off until they can be transferred to a vegetable garden.

Can you start tomatoes in a cold frame?

Tomatoes, planted in many home gardens, are typically a warm-weather crop. ... Planting tomatoes in a cold frame allows you to start your seedlings six to eight weeks before the danger of frost is past.

Can you heat a cold frame?

Cold frames can provide low-cost growing space, but may require heat on cold nights. Low-cost growing structures are used by many growers for short-term production space or winter plant protection. These are not usually heated, but sometimes minimal heat is needed to keep the temperature above freezing.