This time of year, there's always a lot of debate as to how cold and snowy the upcoming winter will be. Throw in the fact that we are in between El Nino-La Nina cycles, and it's anyone's guess. Regardless of what might happen, though, a little effort now will make sure your plants weather whatever blows our way this winter and help them get ready to put on a show for you in the spring.
Lisa Burns and Dee Johnson of the Spokane County Master Gardeners point out that the biggest winter enemies of gardens in the Inland Northwest are freeze-thaw cycles and cold, drying winds. Repeated freezing and thawing of the soil heaves plants out of the ground, splits bark and damages other tender plant tissues. The cold, dry winds that buffet the plants suck out what moisture there is from evergreen leaves. Moisture that the now frozen roots cannot replenish encourages a process called desiccation. Plants such as rhododendrons, roses, butterfly shrubs, some junipers and newly planted shrubs and perennials are particularly susceptible to winter damage this way.
Mulching around the roots and lower stems serves as a blanket and helps even out soil temperature changes and protects buds. In the case of roses, the part of the plant that flowers was probably grafted onto a rootstock. Protecting that graft point at the base of the rose will help the plant survive all but the worst winters. Materials that can be used for mulch include chipped bark, clean straw, pine needles and any other readily available material that will drain water quickly.
"If mulch retains too much water, it can lead to rot and disease problems next year," says Burns. "Therefore, leaves from maples and other large-leafed trees tend to pack down when they get wet and should not be used."
Spokane gets an average of 50 inches of snow each year. While it is pretty and fluffy when it comes down, it accumulates on plants and can cause a lot of damage as happened during Ice Storm in 1996. Tall junipers, columnar trees and vines need to have their branches tied together to keep them from being pulled apart with a heavy snow or ice storm. Depending on the size of the shrub, spiral wrap twine or light rope from the base of the plant around the plant to hold the major branches together.
Mow your lawn one last time. Cut the grass between two to three inches tall, no shorter. Rake up the leaves off the lawn, especially those from large-leafed trees such as maples. With the extra grass taken off, the ground will warm up quicker in the spring. Leaves left on the lawn get wet and pack down blocking out light and air.
Fall is also the perfect time to start getting your garden ready for spring. "Doing weeding now is not time wasted," says Burns. Dandelions, chickweed, weedy grasses and many others sprout in the fall and then go dormant until spring. Digging these and other weeds out and getting them out of the garden will cut back on a major chore in the spring. Till under vegetable garden debris to help nourish the soil with new organic material. Top dress flowerbeds with compost and other organic material and fertilize with a fertilizer very low in nitrogen. The winter rains will carry the nutrients down into the soil where the plants can get it when they begin to grow in the spring.
If your garden was attacked by mildew and other disease and insect pests this year, fall is one of the best times to begin to control them. Many disease organisms grow over winter in leaves and old fruit around the base of the plants or trees. Rake up all the leaves and pick up any old fruits around plants affected this year and throw them in the garbage. Do not compost them unless you are willing to diligently make a "hot" compost pile and make sure the heat of the pile gets hot enough to kill the eggs and spores. "Rake up the leaves of perennials that grow straight from the ground," says Johnson, who battled slugs most of the summer.
Take a few minutes to mark the location of plants that die back to the ground and newly planted bulbs. Little stakes set close to the plants are much more reliable than your memory six months from now. Nothing is quite as frustrating as to dig into a favorite plant or bulb patch in the spring because you thought it was in another spot. Johnson recommends fertilizing the spring blooming plants with a 10-10-10 fertilizer now so the nutrients can be carried to the roots with the winter rains.
Now that your plants have been taken care of, take a few minutes and care for the tools that helped you do the job. Empty soil from terra cotta pots and bring the pots in as moisture in the clay will freeze and shatter the pot if they are left out. Properly drain your sprinkler systems, hoses and faucets. A few extra minutes making sure they are drained will save hours of time tracking down and fixing leaks in the spring. Clean dirt off your hand tools and coat metal surfaces with a light oil to prevent rust. Sand down rough handles and coat them with linseed oil. Clean dirt and old clippings off your power equipment, change the oil and run the gas out of the tanks. And finally, with all the garden chores done, it's time to sit back and relax.