By Dr. Leonard Perry, Extension Professor
Dr. Vern Grubinger, Extension Associate Professor
University of Vermont
You don't need to watch the nightly weather forecast on your local television station to know that there is a chill in the air. Plants feel it, too, and like people, need to bundle up for the winter.
Mulching is one of the best lines of defense for perennial plants against chilling temperatures. Mulching also can prevent the repeated freezing and thawing of soil that causes plants to "heave" out of the ground.
But the trick is not to mulch too soon. Mulching needs to be done after the ground starts to freeze but before the first significant snowfall of the year. If you mulch sooner, mice and other rodents may nest in the mulch, and plants may not be completely dormant. In general, the end of November is a good time to apply mulch in Vermont although if an early snowstorm is predicted, you may want to apply mulch before it hits.
You can use pine needles, straw, leaves, or shredded bark. Straw is the best mulch because it is hollow and that provides good insulation. If you use leaves, make sure they are finely chopped to prevent them from matting down.
Apply a layer at least three to four inches thick around each plant. After you've laid it down, gently pull it away from the trunks and stems to give plants room to breathe. This helps prevent disease problems. Deeper mulching may be necessary in especially cold or windy sites.
To protect evergreens from cold, biting winter winds, build a windbreak. Place posts in the ground on the sides most prone to seasonal winds (usually north and west), and wrap with old feed sacks or burlap. Avoid plastic as this will heat up, causing the plants to burn on sunny days.
Winter sun can scald newly planted trees. Protect them by wrapping the trunks with special tree wrapping tape, which you can buy at most garden centers. Add four to six inches of shredded bark, wood chips, or leaves around the base of the tree. After applying, gently pull mulch away from the base. Wrapping also provides some protection against hungry mice.
Roses require special care at this time of the year. After a freeze has occurred (usually around mid to late November), mound 10 to 12 inches of soil around the base of tender bush varieties. This is not so much to keep the soil warm, but to prevent it from thawing and heaving during the winter. It also helps moderate temperatures around grafted crowns.
Some gardeners add 12 to 16 inches of mulching material such as straw, hay, or pine needles. Although this is not a bad idea, keep in mind that mice can live in it and chew on the stems of the roses. Hardy shrub types should not require much, if any, mulch or protection.
In the garden, there's still time to finish fall clean up, removing stakes, string, and plastic as well as fibrous vines and stems and rotting vegetables. This is also a good time to have your soil tested, so you'll be all set to go next spring.
Soil test kits, with complete instructions for sampling soil, are available from all University of Vermont Extension offices. The basic test costs $10, payable when you submit the sample.
Late fall is not a good time to add fertilizer to the garden. That's because nutrients would be lost through leaching or erosion before plants can use them next spring. However, you could get your composted manure delivered for next season. Be sure to cover it with plastic to keep nutrients from leaching out over the winter.
Like ornamental plants, strawberries benefit from mulch protection, especially when snow cover is shallow or non-existent during winter. Clean straw is superior to hay as mulch because it doesn't add weed seeds to the garden. Apply three to five inches after a hard frost and the strawberry leaves are lying flat on the ground, usually mid to late November, to protect crowns and roots against cold injury and drying out.
This month, rake up leaves from around fruit trees to help control insect populations and remove disease-causing organisms that overwinter on leaf debris. You will help reduce rodent populations by removing all fruit remaining on the tree or on the ground. Applying mulch near fruit trees is not recommended as it increases the likelihood of rodent damage during winter.
Other activities for November: pot and force tulip bulbs for winter
bloom; prune raspberry bushes; start paperwhites in late November for Christmas