Protect plants as winter approaches

It is hard to believe that winter is just around the corner. It has been a beautiful fall. Unfortunately, we are still lacking moisture. To protect perennial plants this winter, it will be important that they go into winter with moist soil.

The exceptionally dry growing season we had this year, coupled with the weather last year, has caused many plants to be under high levels of stress. Watering now will help alleviate at least some of the stress. If these plants do not go into the winter with moist soil, many may not survive. Others may appear to survive the winter and leaf out, but then die suddenly when the weather turns hot next summer.

All perennial plants benefit from watering when soils are dry in the fall, but it is especially important for evergreens because moisture is easily lost from the foliage. Newly planted trees and shrubs are also more at risk due to a limited root system. Even trees and shrubs planted the last two to three years are more sensitive to drought than a well-established plant.

A good, deep watering with moisture reaching at least a foot down into the soil is good. Avoid light sprinklings. Roots near the soil surface are killed when soil temperatures reach 28 degrees F. Therefore, those roots do not last long in our Kansas winters. Our plants rely on roots that are deeper and so we must provide moisture deep enough for them to absorb.

Roses should have some additional attention paid to them this time of year. Most shrub roses are hardy in Kansas, but other types are more tender. Hybrid teas originated in the warm climate of southern China. They need protection to reliably survive Kansas winters.

Roses should be winterized by mounding soil or compost about 8 to 10 inches high around each plant. If using soil, bring it in from another part of the garden. Do not pull it from between the plants because this can damage the rose roots or make them more susceptible to cold. Mounding should be done right now -- around Thanksgiving.

Once the ground has frozen, add a 4-inch layer of mulch such as straw, leaves or hay for additional protection. Do not add the mulch before the ground freezes because this may encourage mice to invade and feed on the rose over the winter. The purpose of the covering is not only to moderate the cold, but also to prevent warm days during the winter or early spring from stimulating growth that is tender from being damaged when cold weather returns.

Krista Harding is a K-State Research and Extension Agricultural agent assigned to Southwind District. She may be reached at (620) 244-3826 or kharding@ksu.edu.