How to Mulch Your Garden for Winter

Time for Mulch

Fall is upon us. Soon the snow will fall, and it's time to prepare your garden for its winter sleep. You will have more success with your hydrangeas, roses, and clematis next summer if you insulate them now from winter's icy blasts. Every perennial appreciates a warm blanket for the winter, and many plants and shrubs require it.

TIP: Our expert gardening adviser, Rachel Klein suggests, "To figure out which of your plants need additional winter protection, first figure out what your USDA Hardiness Zone is. To do this just visit the National Gardening Association's website and enter your zip code!"

Cardboard as Mulch

You can turn that questionable space into a garden plot, simply by utilizing one of the best blankets available - cardboard. Yes, that's right cardboard, along with a thick layer of shredded mulch, will do the tilling for you (You may also substitute several layers of newspaper). Come planting time, that weedy patch will be weed-free and soft enough to plant anything you like.

TIP: Rachel adds, "Remember--remove all labels from cardboard before laying it in the garden!"

If you decide on cardboard, you need lots of it. Huge pieces. Refrigerator huge. Where can you find enough cardboard? Supermarkets, big chain grocery stores, furniture stores, and appliance dealers, all have lots of cardboard. All you have to do is call and ask nicely, or show up and ask in person. Just be certain to bring a pick-up truck or station wagon. You will find yourself with enough cardboard to put to bed every tree, shrub, and perennial in your yard.

How Mulch Works

Plants need light to germinate and grow. Mulch blocks out that light, and it kills everything beneath it, except the worms. It keeps the ground from freezing tender perennials. Cardboard can be cut into any shape you want, or don't cut it at all. Spread it around in curves and circles, using the shredded mulch to shape the desired area. Do not, however, cover your perennials and shrubs with the cardboard. Simply place the cardboard around the plant (cut to fit) and pile-on leaves or pine needles, over the plants.

Cardboard slowly decomposes and enriches the soil. It is, after all, a paper product made from trees, and earthworms love to over-winter underneath it. Best of all, cardboard kills weeds and grass. Come spring, you can simply cut through the soggy cardboard with your gardening knife, dig a hole, and easily plant your new perennials, shrubs, and annuals.

Make certain to overlap the edges of the cardboard, so that weeds have no light to germinate during those warm winter thaws. When first you lay it down, make certain to soak the cardboard with a garden hose, then pile on the mulch, and soak the mulch on top. No need to haul out the hose mid-winter. Your plants are safe. Keep adding shredded mulch throughout the next growing season, and by the time the cardboard has decomposed completely, the weeds will be gone from root to seed.

Cardboard also retains moisture to help plants make it through intense periods of drought.

Structured Cover

If mulch and cardboard alone are not enough to protect your garden, either in the case of an extreme winter or new or damaged plants, structured winter cover is the way to go. One of the simplest cover solutions is placing evergreen boughs over your ground cover. Perennial flowers or herbs like rosemary and parsley benefit from evergreen boughs (such as juniper) because they offer shelter and filtered light.

Still simple, yet somewhat more labor intensive, is the option of a multi-layered mulch. This is an ideal option for beds that need high nutrition, like vegetable gardens, or beds with nutrient-lacking soil. Stack 4 or 5 layers of whatever organic materials you have on hand--leaves, grass clippings, compost, manure, ect.--until it is about 6 inches (15 cm) deep. Use a garden hose to dampen the pile and cover the moistened mulch with a piece of burlap. Affix the burlap to the ground at the corners with tent stakes or heavy stones. In the spring, simply turn the mulch comforter under and incorporate it into your garden soil.

All sorts of containers can be constructed for maximum winter protection, ranging from ones made of chicken wire to "cold frame" structures clad in glass, fleece, or polycarbonate. To build the simplest one, construct a framework of chicken wire around the tender plant in question. Stake the frame to the ground (being careful of the plant's roots). Then, stuff the mesh cage with straw, making sure that all sides of the plant are covered in a 30 cm thick layer. Pack straw on top of the plant and fasten a cover of fleece or polythene over the top of the cage to keep the straw from blowing away.

TIP: Rachel says, "Although winter is not commonly regarded as a time to be concerned about your garden, as you find yourself needing to put on a coat, remember that your plants might be chilly too"