What is the principle of cold frame?
Essentially a bottomless box with a clear or translucent removable top, a cold frame—much like a greenhouse—collects and traps solar energy and converts it to thermal energy (heat), creating an environment that’s more congenial for tender plants than the open air. Somewhere with a clear southern exposure is ideal, as that will allow for the greatest acquisition of solar radiation. In addition to winter growing, cold frames can be used to sprout plants for growth in a regular summer vegetable garden, so building your cold frame near your summer garden is beneficial.In agriculture and gardening, a cold frame is a transparent-roofed enclosure, built low to the ground, used to protect plants from adverse weather, primarily excessive cold or wet. The transparent top admits sunlight and prevents heat escape via convection that would otherwise occur, particularly at night.Seeds and Cuttings As well as being an ideal place for growing vegetables, your cold frame will also be suitable for you to start new plants from either seeds or cuttings. If you have a soil warming cable installed below the cold frame, this will make it possible for you to raise plants from cuttings all year round.Ideally, the cold frame is oriented to face south. A southern exposure provides maximum sunlight and heating capacity. To reduce heat loss, position the north end of the structure near a home, garage or fence.For a cold frame housing growing plants (as opposed to just starting seeds), a south-facing position (in the northern hemisphere) with ample sunlight is crucial. Equally important is protection from harsh northerly or easterly winds, particularly during winter.
What is the best type of cold frame?
Cold frames with wooden frames are strong and sturdy and tend to provide warmer, more regular temperatures, but the frame will need maintenance to prolong its life. Aluminium cold frames are increasingly popular, being light and long-lasting, but may be expensive. For a cold frame housing growing plants (as opposed to just starting seeds), a south-facing position (in the northern hemisphere) with ample sunlight is crucial. Equally important is protection from harsh northerly or easterly winds, particularly during winter. Imagine it as building a sun trap for your plants.Gardeners can anticipate the temperature inside a cold frame to be 5 to 10 degrees warmer than the outside air. Different styles of cold frames exist. One easy cold frame to make is a wooden box with the back taller than the front with a window that acts as the lid.Starting seeds in a cold frame or greenhouse is a smart and efficient way for gardeners to extend their growing season and ensure healthier, more robust plants. It allows you to get a head start on the growing season, giving your plants a better chance to thrive when they are eventually transplanted into your garden.Morning sun is best because it warms the greenhouse early, helping to prevent cold stress on plants. The afternoon sun can be too intense, leading to overheating if there isn’t proper ventilation. An east-facing greenhouse captures gentle morning sunlight, making it ideal for cooler climates.
Why use a cold frame?
In autumn they are useful in protecting cuttings and young plants from cooler, unsettled weather and the first frosts (but only mild frosts). In winter, coldframes and mini-greenhouses can be used to shield alpines from rain and so prevent them from rotting. Starting seeds in a cold frame or greenhouse is a smart and efficient way for gardeners to extend their growing season and ensure healthier, more robust plants. It allows you to get a head start on the growing season, giving your plants a better chance to thrive when they are eventually transplanted into your garden.Cold frames are simple to set up and require minimal maintenance. Gardeners primarily adjust the lid to control the temperature. Greenhouses are more complex, often using automated climate control systems for temperature and humidity management.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.Cold frames are small, passive structures that provide basic season extension and frost protection. Greenhouses offer larger, climate-controlled environments for all-year growing. Cold frames have lower startup and operating costs compared to more expensive greenhouses.
What is the minimum temperature for a cold frame?
An unusually warm winter day can heat up the cold frame and cook the plants! The interior temperature should be kept between 40 and 80 degrees Fahrenheit. Even when below 80 degrees outside, the sun can make the inside of the cold frame much warmer when the lid is closed. However, frankly, the angle of the lid is not critical. Angling it does provide more sunlight to your plants to some degree and allows rain to flow off of it, but I have successfully grown plants just as well in my cold frame with a 20-degree lid.
What is the best size for a cold frame?
Effective cold frames range anywhere from a hole in the ground covered with plastic, to a buried wooden structure made from reǦused materials, to an insulated raised bed using recycled materials. Somewhere around 4s x 8s in size is good to maximize growing space and heat retention. Cold frames can be set up on any surface, including grass, concrete or gravel and they’re easy to move around, so you can choose their spot depending on what’s inside – shade for raising cuttings and sunnier for vegetables.A DIY cold frame can be constructed in several different ways. Some cold frames are made with upcycled window frames. Others look like tiny tents and sit on top of your plants. For this project, you will use wood and sheets of plastic to build a cold frame.Limited space and height – cold frames typically have a smaller growing area and lower height, which can limit the types of plants that can be accommodated. Taller or vining plants may outgrow the available space.Late spring/summer: Throughout the summer months, you can use a cold frame to provide extra warmth for tender summer crops, such as tomatoes, peas, and chillies—which can be quite fickle!
What is the best material for a cold frame?
To build the ultimate cold frame you should use 10mm polycarbonate sheets. It is a quality material that is incredibly strong and durable; just what is required for a cold frame. For budding horticulturalists, a cold frame is a great addition to the garden. Simply put, cold frames are box-like structures that protect seedlings and other young plants from harsh weather conditions.You can put your cold frame on pretty much any surface so long as it’s flat and sturdy. As it’s used to house pots, rather than covering anything growing directly in the ground, concrete or paving slabs make an excellent base.Siting your frame 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. Placed next to the house, a cold frame will benefit from the warmth of the building.You can put your cold frame on pretty much any surface so long as it’s flat and sturdy. As it’s used to house pots, rather than covering anything growing directly in the ground, concrete or paving slabs make an excellent base.Cold frames are found in home gardens and in vegetable farming. They create microclimates that provide several degrees of air and soil temperature insulation, and shelter from wind.