How to Extend Your Growing Season With SmartFlex Sidelights™ As Cold Frames

One of the things I'm most excited about with my Queen of Coops® isn't actually about the chickens. It's what I can do with the garden beds.

I've wanted to try cold-frame gardening for years, but like a lot of gardening projects, it was always one of those things I planned to get around to eventually. I'd need to build the frames, find the right place for them, and figure out what to plant and when. But when I designed the Queen of Coops, I realized I already had the perfect place for them. The coop has long raised garden beds running along both sides, and by adding removable clear polycarbonate covers over those beds, they can become cold frames during the cooler months and return to ordinary open raised beds when warm weather arrives.

For those of us gardening in places where spring seems to take forever to arrive and fall never lasts quite long enough, that's a pretty exciting prospect.

What Is a Cold Frame?

A cold frame is essentially a miniature, unheated greenhouse. A transparent cover allows sunlight into an enclosed growing space, where solar energy warms the soil and air during the day while the enclosure provides plants with some protection from cold temperatures and wind. Unlike a greenhouse, there's generally no supplemental heat involved, which is why it's called a cold frame.

The idea isn't necessarily to grow tomatoes in January. The real magic happens around the edges of the normal gardening season. Depending on your climate and what you're growing, a cold frame can give you an earlier start in spring and keep certain crops growing later into fall. That's exactly what interests me. I'm not trying to turn my chicken coop into a heated commercial greenhouse. Living where I do in the middle of the Bitterroot Mountains our season is very short. I just want more garden: a little earlier in spring, a little later in fall, and maybe fresh lettuce when the rest of the garden has already called it quits.

What Can You Grow in a Cold Frame?

Cold frames are particularly useful for cool-season vegetables such as lettuce, spinach, kale and other hardy greens, along with crops such as broccoli, cabbage and cauliflower. They can also provide a protected place for hardening off seedlings before they're transplanted into the garden.

The important distinction is that a cold frame moderates conditions. It doesn't abolish winter. If it's brutally cold outside and daylight hours are short, an unheated cold frame isn't magically going to become July. But during those transitional weeks when the days are reasonably mild and nighttime temperatures are still flirting with frost, creating a protected little microclimate can make a meaningful difference, allowing you to start sooner in the spring and garden later in the fall. In many climates, cold frames can make growing things like lettuce, spinach and other greens a year-round possibility.

Why Raised Beds and Cold Frames Work So Well Together

This was one of those happy intersections in the Queen of Coops design. Raised beds already lend themselves beautifully to season extension, and my coop already has approximately 50 square feet of integrated raised-bed growing space along its sides. Rather than building a completely separate cold-frame garden somewhere else in the yard, I've designed the coop cover with lower PVC panels that can easily be rolled up when the weather gets warm, and rolled down to reduce drafts when it gets cold without making the coop too dark. Designing this system to also work for cold frames was as simple as adding removable clear twin-wall polycarbonate end panels and pull the clear PVC sidelights out over the raised garden bed. I call these SmartFlex Sidelights™.

What I love most about this design is how easy it is to deploy, plant and harvest under and there are no additional pieces that need to be stored in a garage or that somehow get lost down the road.

There's One Catch: Cold Frames Can Get Hot

One thing that surprised me when I started researching cold frames is that keeping plants warm enough isn't necessarily the only challenge. You also have to keep them from getting too warm.

Even when the outside air feels cool, sunlight passing through a transparent cover can raise the temperature inside a cold frame considerably. That's why traditional cold frames have lids that can be opened or propped up for ventilation. Sunny spring and fall days can require venting, while cold nights call for closing the covers again.

So this isn't quite a "put the cover on in October and forget about it until April" proposition. Temperature and ventilation still need some attention, and that will be part of my own learning curve when I start using the system.

But here again, the inherent design of a Queen of Coops provides the answer: The cold frames keep the cold outside air from getting in, but the backside of the raised garden beds is open to the interior airflow of the coop, vented by the Supernova Roof System® with a powered fan, gently drawing air up and out of the coop through a low opening at the back. The chickens and deep litter ensure the internal air of the coop is free from freezing temperatures even when the outside is affected by a late spring or early fall frost.

The Chickens Have a Role in This, Too

This is where cold frames become particularly interesting to me in the context of the Queen of Coops, because this isn't supposed to be just a chicken coop sitting next to a garden. The whole idea behind the Queen of Coops ecoSYSTEM is to connect the pieces so that the output from one part becomes useful to another.

The chickens produce manure. The Tilt 'N Slide® Compo-Roost moves much of that manure out of the coop and into the exterior compost system, where garden and yard waste can be added and microbes begin doing their work. Finished compost can then go right back into the attached garden beds, where it helps grow food. Adding cold frames means those same beds can potentially produce for a longer portion of the year.

Chickens → compost → soil → garden → food.

The cold frames simply stretch that circle a little farther around the calendar.

Why I'm Excited to Finally Try Cold-Frame Gardening

I want to be clear about something: this part is still an experiment for me. I've gardened for years, but I haven't personally gardened with cold frames before. I'm certainly not going to pretend I've perfected some secret technique for growing spinach in a snowbank.

What I have done is design a system that finally gives me an easy way to try something I've wanted to do for a long time, and there is plenty of established horticultural knowledge behind the basic concept. Cold frames have been used by gardeners for generations, and university Extension programs routinely recommend them as one of the tools available for extending the growing season.

Now I get to find out how well the idea works with the Queen of Coops. I'll be experimenting with different vegetables, planting dates, ventilation and how far I can realistically push the growing season in my own climate. I'll share what works, what doesn't, and what I learn along the way. That's one of the things I enjoy about gardening anyway: there's always another experiment waiting for you.

One Coop. A Longer Garden Season.

The Queen of Coops® DIY Kit was designed around a simple idea: make every square foot work harder. In a 12 × 14 footprint, the system can house chickens, make compost, support trellised crops, grow vegetables and help manage weather around the coop. With removable cold-frame covers over the integrated garden beds, those same square feet can potentially keep producing earlier in spring and later into fall.

That's the part I'm looking forward to testing for myself.

One kit. Garden longer. Harvest more.

Kimberley Fisher

Queen of Coops®