Woody plants can benefit from a dormant or horticultural oil spray during the fall and winter months for numerous overwintering insect pests. Most important of these pests are scale insects and oil sprays are a very effective treatment. Various scale species can be commonly found on camellias, magnolia, holly, citrus, oleander, dogwoods and maples. Be sure to read the label on the container of the product that you use. The label will have a list of plants that are safe to treat. Oil sprays should be applied while air temperatures are between 45°F and 85°F. It is also best to treat at a time of day when the sun is not shining directly on the plant. Now is still a good time for planting hardy shrubs and trees if you didn’t get your planting done in the fall.
Now is also a great time to reassess your landscape design while you can see the “bones” of the garden. If your garden is maturing you may realize that it has become too crowded and needs thinning-be disciplined and bold. Take out weak plants, remove ones that don’t fit the design, reduce the numbers of over-planted varieties and assess which ones may only need a good pruning. Use this opportunity to make room for plants for which you have been lusting!
Pruning trees and shrubs can begin at the end of this month. The reasons for pruning are to remove old, diseased and dead wood to encourage new growth and flowering. Crossing branches that are rubbing each other should also be removed. Pruning should not remove more than one-third of the plant unless you are doing rejuvenation pruning. If a plant needs to be severely pruned on a regular basis because it is in the way seriously consider replacing it.
For thorough information on pruning please visit the Clemson HGIC website: https://hgic.clemson.edu/hot-topic/the-art-and-science-of-pruning/
Hardy perennials can still be planted at this time. Many of them can also be divided and replanted at this time. Make sure that plants don’t stay out of the ground too long. Water in well after replanting. Be sure to try a new and exciting perennial in your planting.
Be sure to keep your winter annuals watered and fertilized. Keeping pansies, violas and snapdragons dead-headed will improve their looks and flowering. If the cold has been severe they may be looking a little rough. They’ll look better as the weather improves but you can trim back any severely damaged parts.
Continue to mow cool-season grasses. Fescue lawns should be mowed at 2-3 inches. Over-seeded annual ryegrass should be kept mowed at 1-2 inches. Hopefully a pre-emergent herbicide was applied in the fall. If not, you can spot treat broad-leaf weeds with an appropriate post-emergent herbicide. Fruit Garden Fruit trees should have been sprayed with a dormant oil in the fall to treat insect pests, especially scale. Another application can be made this month or next month while temperatures are between 45°F and 85°F. Be sure to get good spray coverage on all of the trunk as well as the branches. Remove old plant debris from under trees that can harbor pests. There’s still time to plant fruit trees, shrubs and vines if you didn’t get them all in the ground in the fall. Just be sure the soil is not too wet to be cultivated. Attempting to work wet soil will cause soil compaction.