Types of Cold Frames for Different Uses
Not all cold frames are made alike. Subtle differences in their structure and materials changes important details, like sunlight absorption and warmth retention.
Even within the world of cold frames, Carnival Gardens’ Common Sense Cold Frame model features a unique design that sets it apart.
Most gardens throughout the country employ one of three types of cold frame. Wooden cold frames are arguably the most popular, as anyone with a decent amount of experience with lumber can construct a cold frame out of wood and a plastic or glass top. Wooden sides support the cold frame and block cold winds, aiding in its ability to hold warm temperatures through the night. Because the sides are opaque, however, a wood cold frame is not good at transmitting sunlight. A second type of cold frame features an aluminum frame and glass siding. Though this rendition excels at capturing sunlight, it has difficulty in holding warm temperatures after sunset. What’s more, the glass material could prove dangerous when boisterous children or pets are around.
Carnival Gardens’ cold frames fall into the third and best category — those made with walls of polycarbonate plastic. More durable and safe than glass cold frames, they also rival their wooden counterparts in the absorption of heat and aids in nighttime temperature retention. All cold frames, though, face a similar problem: as the outside temperature escalates, the threat of that heat burning or stressing the plants inside the cold frame grows rapidly. (Unlike glass, polycarbonate walls diffuse sunlight, significantly reducing the risk of heat damage to plants.)
That speaks to one of the distinguishing features of the Common Sense Cold Frame: the self-opening mechanism. The mechanism causes the lid of the cold frame to automatically raise when the temperature inside the frame exceeds fifty-five degrees. This greatly reduces the likelihood of scorch or burns to plants on all but the very brightest and hottest of days.
Every gardener likes to think that they’re diligent enough to raise the lid on their cold frame every day and every time – but even one time not lifting the lid could cause serious problems for your plants! Many gardeners forget that the temperature inside a cold frame can easily rise well above the outside air. Once that air surpasses 55 degrees Fahrenheit, a cold frame’s environment can easily become too warm, especially for cold season crops like lettuce greens and root vegetables. Even one exposure to such heat can cause cool weather plants to bolt, lowering their food value. Ventilation in hot weather is the only way to offset these threats. Thankfully, the self-opening mechanism in Carnival Gardens’ product accomplishes this vital task without the gardener lifting a finger.
Hot beds are a specialized cousin of the cold frame. These devices also use sunlight to warm protected plants. But in addition, the temperature in a hot bed is sustained by either decomposing manure or warmth emanating from an electric cable that is snaked underneath the bed. This additional heat makes hot beds slightly more useful in climates troubled with frostier winters, but they’re also a bit more trouble to maintain. The Common Sense Cold Frame can be used as a Hot Bed if you so desire.
Whether you are considering a hot bed or a type of cold frame, the ways in which you use the product will exert a larger effect on your gardening success than the material of the product. Hot beds and cold frames demand proper placement and setup. Drainage of the soil is so important; it should not be prone to flooding during a rainstorm. The cold frame should be located in the sunniest possible location, ideally facing south to capture as much sunlight as winter will allow. In addition, it may be for cold frames to have access to electricity (especially true in the case of hot beds) and water near to them.