The Clever Way to Reuse Old Tomato Cages to Protect Your Plants From Freezing Temperatures

Wrapped in frost cloth or burlap, an old tomato cage becomes a cheap but effective shelter to protect plants this winter. All sorts of tender shrubs and perennials need winter protection, and temporarily shielding even hardy plants from the worst of the weather can help them thrive. So if you're about to pack away your tomato cages in the shed, stop – they've got another job to do now it's time to winterize garden plants this fall.

Pulling up tomato plants and stacking their cages in the shed until spring is one of the last big gardening jobs of the season. That's a lot of good wire sitting around in the dark all winter, and this trick puts it right back to work. Most gardens have a plant or two that struggles through the cold months, and overwintering plants usually means spending money on shrub covers, frost tents or frames, or insulating zip-up plant jackets built for the job. None of it costs much alone, but the outlay adds up across a whole bed and your old cage can do much of that same work to winterize plants.

This trick won't save everything, but for the right plants a tomato cage wrapped in frost cloth or burlap is a smart, cheap way to help your garden get through winter unscathed. So, if you're gardening on a budget and wondering how to protect plants in winter, here's the smart solution.

Why Tomato Cages Make Such Good Winter Plant Protectors

Throw insulating fabric straight over a shrub and it settles right onto the leaves and buds, and cold will seep through wherever it touches. Wet snow is worse. Its weight can bend or snap branches under the cover. But put a tomato cage in there first and the fabric sits on the frame instead, with a little gap between cover and plant. This method also gives you a frame to fasten the fabric to so it stays put when the wind picks up.

How to Turn an Old Tomato Cage Into a DIY Frost Protector

Start with the cage itself. You'll probably find dried leaves and sections of vine still wound through the wire. If last summer's plants had Septoria leaf spot (Septoria lycopersici) or early blight (Alternaria solani), those scraps can carry it over, so pull every one out and disinfect by scrubbing the cage with diluted household bleach and a rinse.

Next comes the fit. Lower the clean cage over the plant and see where the branches end up. Any branch poking through the wire is, more or less, where the fabric will touch the plant later, so the stems need room inside. Push the legs down firmly and, out in an open, windy bed, tie it to a sturdy stake if needs be.

Now wrap the frame in breathable frost cloth or horticultural fleece: one Agfabric frost blanket, available from Home Depot, covers more than one cage. Fasten the fabric to the frame using clips like these stainless steel garden clips from Walmart. Take the fabric right down to the soil as warmth comes up out of the ground at night and a gap at the bottom lets it leak out. Pin the fabric to the ground with galvanized landscape staples like these from Walmart.

Skip plastic wrap, because the plant needs to breathe and a wrapped cage heats up fast on mild afternoons and damp, still air favors gray mold (Botrytis cinerea). Even without a waterproof wrap, peek underneath every few days and let some fresh air in if needs be. Once the cold snap is over, take the temporary covers off, leaving the frame in place ready for the next weather dip.

Which Plants Benefit Most From This Trick?

Depending on your USDA zone, the plants that need winterizing in fall aren't just those that aren't hardy enough to survive plummeting temperatures: you can use this trick to extend a crop or protect next year's flower show, too. Ever had a hydrangea leaf out nicely and then barely bloom? Bigleaf hydrangea (Hydrangea macrophylla) is the classic candidate because it forms next year's flower buds on old wood, and those buds sit on bare stems all winter. Hard freezes can kill these delicate buds so while the foliage comes through just fine the following year, blooms are few and far between.

Hybrid tea roses and perennials that are borderline hardy in your zone are good candidates too. If you've planted young shrubs this year – especially if you've been tempted by Black Friday sales on evergreen shrubs and you're planting late in fall – they'll also benefit from being kept cozy during cold snaps. Boxwood and other small evergreens can pick up winter burn from drying wind and sun, and burlap like this Wellco natural burlap roll at Home Depotcuts down on both without pressing on the foliage.

Of course, you'll need to match the plant to the cage size. But if you're planning to upgrade your tomato cages to use a more substantial modular tomato support set-up like these heavy-duty square tomato cages, also from Home Depot anyway, it makes sense to do so now when you can use them to protect bigger shrubs that need a wider frame.

For Extra Protection, Fill the Cage With Insulating Leaves or Straw

Once the plant goes dormant, usually after several hard frosts, a sturdy cage can be packed with loose insulation to provide further insulation too. Dry shredded leaves, straw or pine straw like this from Amazon is best. On a bigleaf hydrangea, you can fill right up around the buds, while roses mostly need the extra insulation over the crown and lower canes.

Keep that fill dry and loose. Leaves raked off a wet lawn and packed tight against living foliage or a crown stay soggy, and that can lead to rot, so let them dry out first before covering with frost fabric. In spring, pull out the fill a little at a time once the worst cold has passed.

What This Trick Won't Protect Against

Frost cloth doesn't make any heat of its own, but only slows the loss of warmth rising from the ground at night, buying a few degrees on a clear, still night. In a long, deep freeze, the soil underneath cools off too, and that leaves the cover less and less to work with. Truly tropical plants won't turn winter-hardy inside a wrapped cage, either: hibiscus and mandevilla belong indoors once nights turn chilly, well ahead of frost. In colder regions, some tender plants on the edge of hardiness still do better potted up and stored in a frost-free spot.

For most of the year, a tomato cage has one job. But with a cozy comforter of frost cloth, a few clips and a bit of care, this garden staple picks up a second role in winter, sheltering plants that would otherwise need a store-bought cover and helping to ensure another flower-filled year in your garden. When spring comes, unwrap your precious plant, hose off the cage and send it back to the tomato bed. It's the same old cage pulling double duty, and this trick to reuse it over winter barely costs a dime.