University of Maryland Extension

November Tree and Shrub Tips

poison ivy fall color
Poison ivy leaves are red, orange and yellow in the Fall.  Photo: Steve Dewey, Utah State University,

(More tips from HGIC)

  • Continue to watch out for poison ivy. Do not handle the hairy poison ivy vines wrapped around trees. This is a good time to sever poison ivy vines at ground level and paint the cut end with a full-strength herbicide labeled for brush killing that contains triclopyr. Be careful not to bring firewood into the house with poison ivy vines attached.
  • Nursery stock trees and shrubs can be planted until the ground freezes. Carefully examine trees and shrubs prior to purchase to assess quality. Carefully remove container stock plants to examine root systems. Avoid shrubs with dead roots; dead roots are brown instead of white, or those that are tightly circling the stem or trunk. These can girdle the trunk later. If you buy container grown plants be sure to spread the roots out in the planting hole. (Cut down the sides to encourage new root growth.) With balled and burlap stock cut the twine around the ball and cut away the nylon or burlap wrapping. (PDF HG 24 Planting Tips for Trees)
  • It is too late to transplant trees or shrubs. Be sure to keep all plants well watered during dry periods this fall, especially those that are newly planted or transplanted. Avoid planting problem trees such as silver maple, Bradford pear, and Norway maple.
  • Fall is also a good time to fertilize trees, especially if they have not been fertilized in 3-4 years and seem to be growing slowly. Broadcast 1 to 1.5 lbs. of nitrogen per 1,000 sq. ft. The granular fertilizer should be applied under the tree’s canopy and extend 8-10 ft. out from the canopy. Use a low phosphorus fertilizer. It is rarely necessary to fertilize a mature tree. Newly planted and very young trees and shrubs benefit the most from tree fertilization. Trees and shrubs can be fertilized as long as the ground is not frozen. Trees that are surrounded by lawn do not need fertilization. Follow lawn fertilizer recommendations.
  • Trees and shrubs can be pruned now. (PDF HG 84 Pruning Ornamental Plants) Because the leaves are coming off of deciduous plants you can more easily see the structure of branches and determine what pruning needs to be done. Begin pruning by removing all dead, diseased branches and making any necessary cosmetic cuts. Wait until your shrubs are dormant for all other corrective and cosmetic pruning. Flower buds are forming or are already formed on spring flowering shrubs. Unless it is absolutely necessary avoid pruning spring flowering shrubs until after the bloom period if you do not want to sacrifice next spring’s bloom. 
  • Mulch should be applied only 2-3 inches deep around ornamental plants and kept away from shrub and tree trunks. Excessively deep mulch makes a favorable site for voles to tunnel and feed on shrub stems over winter. You may notice interior older leaves yellowing and dropping from rhododendrons and other evergreen shrubs. This is normal for this time of year.

Insect pests

    • Shade trees and shrubs that have had scale problems can be sprayed with horticultural oil after leaves drop. Again note, the temperature must remain above freezing for 24 hours after spraying oil. Follow label instructions.
    • Continue to remove bagworm bags from trees and shrubs. It’s important to dispose of them in the trash, do not leave them on the ground. If you simply throw the bags on the ground, the eggs inside them will still hatch next year. (HG 32 Bagworms and Their Control)
    • The egg masses of the Eastern tent caterpillar should also be pruned out. They resemble shiny, black styrofoam and can be seen on the ends of wild cherry and crabapple trees. (PDF HG 21 Eastern and Forest Tent Caterpillar)
    • Spruce spider mites are active again on evergreen trees. Monitor for this pest by tapping branches while holding a piece of white paper underneath. Look for moving specks. They can be controlled with ultra-fine horticultural oil. Follow label instructions.
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