Karen Cambre, Sharpe, Kenneth W.
News article for January 1, 2018
The start of a new year is full of expectations and promise. It is a time of reflection and a time for looking forward and resolving to improve.
One of my resolutions is to take better care of my landscape. It is so much more than cutting the grass, trimming and edging. There are some of the chores that can only be accomplished in the dormant season and this workout is less expensive than a gym membership.
Scales are insects that can be a real problem for a number of plants and they are difficult to control, especially in the warmer seasons. Scales are sucking insects that have a piercing mouth part for sucking plant nutrients and they are covered in a protective shell for protection. One of the first clues that you have scales is the presence of sooty mold, which is the black flaky mold that covers leaves and twigs of plants, but can be rubbed off with your fingers.
Now is a great time to scout plants for scales. Plants that are particularly vulnerable would include citrus, camellias, fatsia, privet and euonymous. Scales appear as bumps on the underside of their leaves, twigs and branches. These bumps are usually small, circular and appear as gray, yellow and white and there is even a bright orange/red one that I see on citrus.
The best control for scale is to use dormant oil, but it can only be used in the dormant season as the oil will burn leaves in warm temperatures. If you have scale on citrus, wait until you harvest the fruit before spraying and you might wait for camellias to finish flowering. The oil will cover the scales and suffocate them. You can get even better control if you will add Malathion in with the dormant oil spray. Do not spray oils within 48 hours of a freeze as that can cause leaf burn.Another concern that I hear all throughout the year is lichen. Lichen is the greenish gray mossy growth that people find growing on the trunk and branches of trees and shrubs. It is tightly adhered to the bark and they associate it with declining plants.
Lichen is not parasitic and almost never the cause for decline, but some people find it undesirable and want to control it. By far the easiest time to control lichen is the winter with copper fungicides. We spray plants in the winter because it is easier to get good coverage of twigs and branches without leaves present, but most of all because copper can burn green leaves once it warms up.
Spray shrubs or trees that have undesirable lichen growth and get good coverage. Once sprayed, lichen will turn a copper color. Recheck after two weeks and make sure the lichen has changed color. Once you see the color change it will be several months before the lichen falls off because it is firmly attached. If you do not see the color change, repeat your spray.
It is not necessary to control lichen since it is not deriving any benefits from your plant. Lichens are nourished by fixing nitrogen from the air, they only use the plant as a structure to attach itself. You will also find lichen growing on rocks, buildings, fence posts and outdoor furniture. Obviously it is not getting nutrients from these sources.
If you need to move a small tree or shrub, winter is the time for transplanting. Maybe you have a family heirloom plant that you want to take with you or need to relocate. During dormancy you have your best chance at survival.
Dig up the plant with as much root ball as possible. Dig your new planting hole the same depth as the root ball and twice as wide. It is critical to backfill the planting hole with the original soil that was just removed and then mulch to conserve moisture.