There are a few chores you can do now that will prepare your garden and roses for next year (if you haven't already completed them). Taking time now to cleanup plant debris and properly protect your roses will pay off in healthier plants next year. Many of the fungi and bacteria that cause spots, blights and rots of plants survive the winter in the dead leaves, stems and other plant debris that are left in the garden. When warm weather returns next spring, those pathogens will come out of dormancy and attack the young plants. Good sanitation is essential for a healthy garden. Raking up and disposing of infected plant debris is an important step in reducing disease next year.
How can you dispose of infected debris? One option is to compost. It is important to have a compost pile that heats up to at least 140 degrees Fahrenheit, which will kill most pathogens. Most home compost piles do not reach this temperature but most municipal composting facilities will. Another way to prevent plant diseases next year is to record where each type of plant was grown this year, then rotate where each type of plant is placed in the garden next year. This further reduces the chance that new plants will be exposed to this year's over-wintered pathogens. A rotation cycle of several years is best to minimize disease but even a two or three year rotation will help.
It is important to provide winter protection for roses such as hybrid teas, floribundas and grandifloras because the low temperatures and rapid temperature changes in winter can severely injure or kill unprotected roses. Prepare roses after plants have been hardened by several nights of temperatures in the low to mid twenties. Normally this is early November in northern Iowa.
Remove fallen leaves and other debris from around each plant. Then loosely tie the canes together with twine to prevent the canes from being whipped by strong winds. Extremely tall canes can be cut back to two and a half to three feet; then mound soil ten to twelve inches high around the base of the canes. Place additional material, such as straw or leaves, over the mound of soil after the ground freezes. A small amount of soil placed over the straw or leaves should hold these materials in place. Remove protective materials before bud break in spring, normally about mid-April in northern Iowa.
To prevent rabbit damage to young trees and shrubs, place chicken wire fencing or hardware cloth around them. The fencing material needs to be high enough that rabbits won't be able to reach or climb over the fence after a heavy snow. To prevent rabbits from crawling underneath the fence, bury the bottom two or three inches below ground or pin the bottom of the fence to the soil with u-shaped anchor pins.
For more information, contact the Grundy office of ISU Extension at 319-824-6979.