Growings On: Ornamental care in the fall

Published 11:00 am Wednesday, October 18, 2023

Landscape shrubs benefit from a little tender loving care in the fall. If they are hungry going into winter, they have a much greater chance of cold injury and poor recovery the following spring.

Azaleas that are rapidly turning yellow or if the older leaves are yellowing and falling off can indicate a lack of nitrogen so a soil test would be a good idea, to see what nutrients they need. If you have the red-flowered types, their leaves often turn reddish-brown before the leaves fall off. Late summer and early fall are the ideal times to prevent this yellowing from occurring. The best option for fall fertilization in the landscape are slow release fertilizers, which you can find at any plant nursery or garden center.

Light pruning in the fall will work wonders to shape up shrubs for winter. Hollies and magnolias can be saved until later, when you want to cut some foliage for holiday decorating.

When light pruning, only remove long branches, as well as dead, damaged or diseased branches. Also cut back those branches that interfere with mowing, sidewalks and driveways. Pruning cuts should be made back into the interior of the plant at a point where the branch is attached to a larger stem.

Heavy pruning or shearing of evergreens in the fall is not recommended because there is not enough time for new growth to harden off before cold weather arrives. Heavy pruning in the fall makes plants much more susceptible to winter damage and death. Also, pruning in the fall removes buds from next year’s spring-flowering shrubs. Fall pruning should be lightly done and only to shape the plants.

Sanitation under your shrubs in the fall can help reduce disease and insect pests the following growing season, too. Collect the leaves from all roses and shrubs that exhibit black spot or other diseases as well as the ones from camellias and sasanquas that are deformed by leaf gall, and make sure to burn or throw them in the trash, don’t compost them. Removing the source of the disease will help protect next year’s growth. Look for bagworms on evergreens and remove and destroy them, too. Watch for spider mites — populations tend to increase in the fall before cold weather arrives.

If you want to rearrange or move shrubs, planting and transplanting are best done in the fall. Especially those not doing well in the shade would benefit from moving to a sunnier location.

When digging up shrubs, take as much of the root system as you possibly can to reduce transplant shock. Prepare the new planting location by thoroughly loosening the top 12 to 15 inches of soil three feet around the new planting hole. Set the transplants at the same depth and in the same orientation to light that they had at their original location and work the soil around the exposed roots. Keep the transplants moist but not water logged. Excessively wet roots and poor drainage are probably the greatest cause of shrub death. It is important to mulch around the newly-transplanted shrubs to protect the roots from freezing soils as they adapt to their new location.

Now is also the time to begin any renewal or revitalization of your landscape. Go ahead and remove those heavily overgrown shrubs, particularly junipers that do not respond well to renewal pruning. Excavate the existing old roots and prepare your new planting bed. Select new plants that are slow growing and will not overgrow your space. Fall planting of shrubs allows good root expansion and helps promote next year’s plant growth without a lot of extra care.

If you have any questions, feel free to contact Brenda Jackson, the agricultural and natural resources agent for Murray County Extension, at (706) 695-3031 or bljack@uga.edu.