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Cold Frame Components

This is the gold standard of cold frames (photographed in London at the Chelsea Flower Show). Made of powder-coated aluminum by Alitex, one of England's premier greenhouse manufacturers, it's built to last for generations with a mortared brick base.

If you have a greenhouse, a cold frame sited to take advantage of sunlight on a south-facing wall is ideal for hardening off seedlings before transplant. Pots or trays can be placed inside, with the glass top supported by metal rods during the day and closed at night for protection.
by Paintbox Garden
While touring estates and public gardens in England, I had the opportunity to visit Heligan in Cornwall and took this photo just before crews moved the healthy squash starts into prepared beds in the walled kitchen garden.

This cold frame has a gravel base so it's used almost exclusively for transplanting purposes. Propagation is done in the heated greenhouse, where conditions can be kept sterile.

If you propagate with a light stand indoors, trays full of seedlings can be moved to a cold frame for about a week before transplanting once the threat of frost has passed.
by Paintbox Garden
Here's another view of the structure. You can see it has a concrete base and painted wood framework with a custom glass top. The young plants were pulled from the warm comfort of the heated greenhouses by the horticultural staff on a mild spring day, to be exposed to several days of cool weather, wind and rain before being moved.

In this case, the cold frame plays a crucial role in the garden scheme as a layover for tender starts.

Note the slanted top, which allows water to drain away and optimizes solar gain.
by Paintbox Garden
This is another type of cold frame, an elegant little conservatory of sorts, made of glass and metal with a quaint removable lid that allows air to circulate around transplants or new seedlings when weather remains unpredictable — absolutely charming, very British!

Glass cloches offer similar protection — they're large domes that are placed over seedlings at night during the spring chill. You can find these in antique markets and upscale garden shops — or maybe your grandmother has a few lying around the tool shed.
by Paintbox Garden
Growing Edibles

If your cold frame will be used for active propagation, be aware that many edibles dislike transplanting — particularly tap-rooted crops like carrots and beets, which are best grown in situ and sown directly into garden beds.

Greens rich in antioxidants, vitamins and minerals — like arugula, kale and chard — are all good candidates for sowing in batches every few weeks once soil temperatures reach about 50 degrees Fahrenheit (use a soil thermometer to check).

Here are some I've ordered through John Scheepers and Renee's, which I'm excited to try, particularly the arugula with its delectable bite.

Success with growing edibles in a cold frame depends on soil temperature, which is widely variable depending on where you live. Get organized in December and start to measure your soil temperature in January, testing every two weeks. Seed packs have planting instructions, usually saying "sow as early as soil can be worked" in early spring, meaning the ground isn't frozen.

Don't have a soil thermometer? Get one at your garden center or order online.
by Paintbox Garden
Chard (Beta vulgaris) is a cool-season annual that's ideal for growing in a cold frame. Follow germination directions on your seed packet and soak in warm water briefly before shaking out in loosely worked soil dressed with compost. Seeds take about 10 days to germinate.

One of the super foods rich in antioxidants and minerals, chard can be sown successively throughout the growing season, its leaves delicious chopped in soups or added to omelets. When harvesting, cut the outer leaves first. Baby chard seedlings are tender and sweet.

A Gourmet Greens Braising Mix from Renee's Garden contains 'Silverado' and 'Eldorado' chards with two kinds of beets — all meant to be thickly sown and harvested when 6 inches tall, then lightly sautéed.
by Paintbox Garden
Red and green mesclun is another easy-to-grow health food; pull the seedlings when small and add to early spring salads. Plants can be thinned and then transplanted elsewhere in the garden.

Gardening Tips

Just like a greenhouse or regular garden bed, a cold frame needs attention. Soil amendment, even hydration, proper ventilation, keeping plants labeled and re-seeding are all part of the fun.

If you have a frame that needs to be propped open manually and closed at the end of day, be careful not to forget as young plants left in an unopened cold frame can be killed by excessive heat on a warm day.

In August or early September, sow more cool-season edibles into your cold frame to extend the growing season, and keep the top propped open. (Closing it is only necessary when freezing temperatures hit.) Who knows, by Thanksgiving you could be cutting baby spinach for a gourmet salad.

More: How to Grow a Cool Season Vegetable Garden
by Paintbox Garden

Comments

Gambrell Renard Home Decor very interesting. thanks for sharing
4 months ago ·
c2blum hope to work a coldframe or greenhouse after the kids go to university.
just can't get any more local than homegrown!
4 months ago · ·
llswink I do this with chard, lettuce, bok choy and cilantro every winter! I don't have a proper cold frame (can't afford it). I use a *hoop house set up over one of my raised beds. It is January with temps down to the 20's and I still have fresh greens for salads and cooking! Anyone can grow in winter if you know how. Read Eliot Coleman's "Four Season Harvest" for details.

*(My hoop house is made of PVC pipe that is bent and slipped over rebar pegs in the soil. I then cover it with heavy plastic sheeting and weight it down on the edges with stones and bricks. At the end of the cold weather season it all comes apart and is stored away.)
4 months ago · ·
Linden L.A.N.D. Group Wonderful Charlotte!
4 months ago ·
kjdick Oh you're killing me! I just sold a little greenhouse just like the one pictured. I never even thought of putting it in the garden. Oh well, now I know.
4 months ago ·
julietjones Would have liked to see photos of cold frames that are sold in the USA, ready-made, (no building required). I know that "Gardeners Supply company" sells one, also the Juwel cold frame is said to be a good one...Would love to hear your readers' recommendations!
4 months ago ·
Conservatory Craftsmen Very clever!
4 months ago ·
johndanks Cloches on the cheap: check with your local bottled water supplier for cracked 5-gallon plastic jugs. Cut the bottoms off - instant cloche! Cracks running up the side can be patched with tape. Don't forget to take off the caps so your plants don't get cooked.

I found the best way to cut the bottoms off is improvising a U shaped piece of wood out of scraps and clamping the neck of the bottle in it. Then cut around the bottom with an angle grinder.
4 months ago ·
Ruth thanks for the article Charlotte. Love heirloom seeds, they can be collected from mature plants and used/shared the next year.
4 months ago ·
RollingPlanter.com Another means of extending or starting your plants early is using our rolling planters. Garages, sun porches can be easily transformed into areas that can allow many to grow the vegetable and herbs. The boxes have deep cavities that allow all deep rooted vegetable and even trees to thrive.

We need to do more to grow vegetable and other plants in the spaces we have. We need to reduce our carbon foot print and start eating healthy foods.

-KP ( rollingplanter.com ) http://www.houzz.com/pro/rollingplanter ; http://www.rollingplanter.com
4 months ago · ·
suevh10 My husband made my cold frame for me. It's practical and inexpensive. We got the perspex Plexi glass) cut to size at our local hardware store. He also built my tuteurs for me after I took some pictures of some I saw in a country store at home (England). A little piece of my home here in the deep south. Huntsville AL.
4 months ago · ·
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