Cold Frames for an Early Start to Your Garden
Garden Cold Frames - Extend Your Growing Season
Most gardeners are ready and raring to go in the early spring; seed catalogues have been flipped through and ordered from and you just want to get those vegetable seedlings in the ground! Whoa! It's too early so how do you quench the thirst for getting something growing? A cold frame is a good way to get started with the early garden, and works well with a raised bed garden in particular. Here is a look at some features to be mindful of when using a cold frame to start your garden.
Jump Start Your Seedlings!
Gardeners are usually looking for ways to get an early jump on crops or get more of them. One way to accomplish this feat is to start seedlings early in a cold frame.
If you live in the northern states, the gardening season seems like it may never start, and it's just too short for some long season warm weather vegetables like okra or some varieties of melons. For those in the south, it would seem that the growing season is long enough, but with the very hot summer months some crops just either won't survive the heat and dry weather, or even if they do survive, they won't produce much when temperatures get above 85 or 90 degrees. This includes some of the old standby favorites like tomatoes and greens like lettuce.
While many vegetables can be started indoors, one problem with doing that is that they get acclimated to either greenhouse or indoor conditions and can be ill-suited to set out early in the season when the nighttime temperature swings can be at their most extreme. These tender seedlings can be easily damaged by temperatures close to freezing. One way to help them acclimate is to "harden them off" which is basically the methodology of slowly introducing them to the outdoor environment.
The old standby tool for doing this is a cold frame. A cold frame is similar to a raised bed garden, as it can sit above the main garden, but it is covered with either a poly or glass window.
Cold Frame or Hot Bed?
Sounds fun, doesn't it?
A cold frame differs from a hot bed in that a hot bed usually incorporates an additional heating source, and doesn't depend only on the solar heating from the sun shining through the window like a greenhouse. These additional heat sources can be as varied as a simple resistance wire electric heater to situating the bed over a manure pile.
Cold frames can also be used to help perennials over winter in colder temperatures. Cold frames are a great addition to any gardeners arsenal, and can be made or purchased in a size to fit your specific gardening needs.
Building a Cold Frame
A cold frame can be a simple stack of hay bales around the planting bed with an old window on top of the bales, or a wooden box (like a raised bed garden frame) can be built to fit the window and form a tighter seal from outside air keeping the thermal temperature at desirable levels.
Either way, you need a tight seal as the slightest bit of (freezing) cold air getting through the seal will be doom to your plants and plans! May sure your top material is placed at a slight angle so water will run off and not collect on top.
If you are using the frame in warmer temperatures, it may be best to have your window on hinges so you can prop it open to allow some air circulation and regulate the temperature inside so the plants do not over heat.
Commercial cold frames can be purchases as well. Some are simple polyurethane tents that fit over just a few plants. Others are large raised beds that are designed to stay in place the entire gardening season. This would have a removable cover for ease of use in cold and warm weather.
Repurposing and DIY All In One
Our friends live on 20 acres on the outskirts of an urban area. They are planning on converting this existing structure to a cold frame or greenhouse to start their seedlings. What a creative way to use a space already on the land. Note the great angle already in place!
Frost Dates and Spring Garden Calculator
Cold frames will indeed help you get your garden started early, but you must still be aware of the initial planting date and the first frost date for your area. These dates are an average time of when you can start to plant and when you can expect the first frost. Of course, Mother Nature is in charge so they are only guidelines for the area you live in. In our household, these dates are as commonly known as birthdays or holidays!!! If you do not know your regional information, use this very handy calculator by inserting your zip code.
This content reflects the personal opinions of the author. It is accurate and true to the best of the author’s knowledge and should not be substituted for impartial fact or advice in legal, political, or personal matters.
© 2010 Joanie Ruppel