What to do in your garden in December
Fresh holiday color-makers. If you're looking foralternatives to poinsettias, these indoor plants have colorfulflowers or foliage: azaleas, bromeliads (Guzmania hybrids), Christmas cactus (Schlumbergera x buckleyi), kalanchoe, or Phalaenopsis orchids.
Living Christmas trees. Four hardy candidates are alpinefir, Colorado blue spruce, Engelmann spruce, and white fir. Duringits indoor stay, care for the tree as suggested at left. After theholidays, move the tree to a cool, bright porch where its rootballwon't freeze. When the soil is workable, you can transplant it intothe garden. Norfolk Island pine (Araucaria heterophylla) is a subtropical conifer you cankeep indoors year-round.
Care for poinsettias. Select plants that are fully colored,with dense, green foliage all the way to the bottom of the stems.Before you leave the store, have the whole plant wrapped in aplastic or paper bag to protect it from cold air during transportto the house. Place in a room that's cool but not drafty, away fromheat sources, and where it will get at least six hours of bright,indirect light. Water whenever the soil dries out, but don't letthe soil get soggy or allow water to puddle in the saucer.Poinsettias don't need fertilizer during bloom.
Control whiteflies indoors. Plants brought indoors tooverwinter may harbor whiteflies, which can quickly spread to otherhouseplants and reach damaging numbers. To control, spray infestedplants every 5 to 7 days, applying neem oil for two treatments andsummer oil for the third treatment. Be sure to spray the undersidesof leaves to kill the eggs. Set out yellow sticky traps to catchflying adults. In greenhouses and sunrooms, release predatoryEncarsia wasps, available from Planet Natural (www.planetnatural.com or800/289-6656).
Identify garden microclimates. Walk through your garden tosee where the snow lingers longest. Snow provides good insulationfrom extreme cold, making these places ideal microclimates forbroad-leafed evergreens like boxwood and conifers such asarborvitae and yew. They're also suitable spots for perennials thatneed protection.
Prevent snow damage. To prevent a heavy snow load fromdamaging conifers, tie branches loosely with twine in the directionthey bend easily, the same way growers bundle cut Christmas treesfor delivery to sales lots. To protect daphne, holly, rhododendron,and other delicate shrubs, construct a "tent" over the plant eitherwith snow fencing or two pieces of plywood or heavy lattice,attached with hinges at the top like a sandwich board. For smallplants, wrap burlap around a frame of stakes pushed into theground; leave the top open.
Study your winter landscape. Make note of areas in your yardwhere evergreens could make the winter landscape more interesting.Choose needle-leafed ones for sunny areas and broad-leafed kindsfor shade. Also consider where ornamental grasses would make astrong statement. Mark future planting sites with a stake, theninstall the plants when they become available next spring.