In this series, we’re breaking landscape management down into basic parts. We covered lawns in Part 1, and here we’ll look at the tasks and timing of caring for landscape trees and shrubs. Because they are both woody, perennial plants, they share many of the same basic care requirements.
Task 1 – Pruning
Pruning is essential for the appearance and health of woody plants. Timely pruning stimulates spring growth and flowering.
Late winter to very early spring is the best time to prune most trees and shrubs, when flowing sap quickly seals the wounds to protect against pests and diseases. Spring flowering shrubs like azaleas, forsythia and blueberries, however, set their flower buds for next year in the current growing season. Wait to prune until after their flowers fade or you have harvested the berries.
Through different types of pruning cuts, we can maintain the shape and size or woody plants, remove dead or damaged branches, and reduce disease problems.
Thinning cuts remove selected branches back to the trunk of the tree or shrub. They are used for both health and aesthetics to reduce crowding. Thinning opens space between branches to let sunshine reach the interior of the plant and air to flow over and around leaves. Together, sun and air circulation dry excess moisture from leaf surfaces to help fight off fungal diseases.
When thinning trees or shrubs, start by removing dead and damaged branches. Then look for branches that turn inward toward the center of the plant and remove those. Crossing branches that rub together can open wounds that allow entry of pests and diseases. Identify the more desirable branch and remove the one that crosses it.
Heading cuts remove part of a branch and are typically used to manage size or to remove diseased portions of a branch. Shearing removes branch tips across most or all of the plant to shape or maintain a uniform hedge. Both of these pruning cuts stimulate side shoots to grow, creating bushiness. Over time, plants that are perpetually sheared move all their growth to the outer perimeter of the plant.
Rejuvenation pruning, sometimes called renewal pruning, takes shrubs down to 8-12 inches above the ground. It’s a recommended practice for butterfly bushes, and can bring overgrown broadleaf shrubs back into scale, at least temporarily.
Task 2 – Irrigation
As a general rule of thumb, trees and shrubs need about an inch of water each week, even during dormancy. When rainfall isn’t enough, apply supplemental water at ground level in a wide circle around the plant, where the roots are growing. Avoid wetting plant leaves.
Task 3 – Fertilizing
Flowering and fruiting trees and shrubs need moderate fertilizer applications when they begin to bud out in March, and again in May and/or June. Apply fertilizer to the root zone and water in immediately. Trees and shrubs growing in the lawn area typically receive adequate nutrients from applications of fertilizer to the lawn. Excess fertilizer can damage plants.
Task 4 – Pest management
The first steps in pest management are detection and identification of pests.
Only three percent of insects are pests; the remainder are either beneficial, like bees, or are just a natural component of the ecosystem. Spend time observing the plants in your landscape to become familiar with what is normal. When you notice issues, you can always contact your Extension office for identification and treatment advice.
With frequent scouting and timely care, your landscape trees and shrubs will add beauty and value to your home, and provide food and habitat for pollinators, birds, and other wildlife.
Contact UGA Extension Forsyth County at 770-887-2418, or visit our website at extension.uga.edu/county-offices/forsyth.html.
Heather N. Kolich is the Agriculture and Natural Resources agent for the UGA Extension Forsyth County.