The past three winters have caused considerable injury to evergreens. Many evergreens were damaged by the desiccation associated with drying winds and the sun reflecting off the snow during the winter of 2000-01. The unusual temperatures of the winter of 2001-02 prevented the trees from hardening off properly and some winter damage resulted. Then the lack of snow cover and erratic temperature fluctuations of 2002-03 injured or even killed many evergreens including the lower shrub types. By now you have had plenty of opportunities to assess junipers, arbor vitae and other evergreens in your landscape. If they have not recovered adequately to be of value to your landscape, you probably should consider replacing them. Or, if you’re looking for ways to add color to your winter landscape, consider adding some pine, spruce or fir trees. In either case, don’t feel compelled to plant the largest specimens you can find. Small evergreens will transplant more easily and generally “take off” faster after transplanting. September is an excellent time to plant young evergreens. There are many advantages to planting evergreens at this time of the year. The new, tender growth that developed in May and June is tougher now and less vulnerable to transplant stress. The longer, cooler nights and slowly declining daytime temperatures mean reduced moisture loss through the needles. This, in turn, creates less demand on the plants limited root system. In addition, there is usually ample rainfall in autumn, although moisture has not been a problem in most of the area this summer. Evergreens also benefit from the warmer soil temperatures that allow the plants to become established before winter. Because evergreens retain their needles throughout the winter, it is more critical that they be planted early enough in the season so that their roots begin to function before the soil freezes. Another advantage you shouldn’t overlook is that most nurseries offer a fine selection of trees and shrubs, including evergreens, at discounted prices this time of year. After planting the evergreens, spread three or four inches of an organic mulch like shredded bark or wood chips over the root area. This prevents the soil from freezing as early as it would otherwise and also protects the roots from autumn’s fluctuating temperatures. Spread the mulch over the root area as far as the branches reach or even a little further, but don’t place the mulch directly against the trunk. Pull the mulch away from the trunk an inch or two to promote good air circulation. Watering is certainly important, but bear in mind that the combination of cooler temperatures and more frequent rains in autumn should reduce the need for regular watering. However, any time we go a week without good rainfall, give the root ball and the area around it a thorough soaking. Because evergreens continue to lose moisture through their needles year-round, it’s very important that you continue to water them right up until the time the ground freezes. However, don’t make the mistake of watering every day or two as this can saturate the soil and cause root rot, especially in clay soil. Deciduous trees and shrubs may be planted in September, but they can also be planted after they’ve gone dormant and have lost their leaves. Because they lose their leaves, it is not as important that the roots are established and functioning before winter. Like evergreens, it is important to mulch the soil over the root ball area to prevent the soil from freezing a little longer.
