Lexington, Kentucky 40546
      
Nursery Update - A University of Kentucky Cooperative Extension Service update for the Kentucky Nursery Industry
  
By Amy Fulcher, Extension Associate - Nursery Crops
  
University of Kentucky Department of Horticulture
  
Update #4
  
July 17, 2002
  
Pruning:
Timely pruning is essential for a high quality, salable tree. Uniformity in size, shape, and quality are all impacted by pruning.

What to do with tall central leaders?

• Try using a section of a stake to continue to train central leaders as they outgrow the original stake (if there is one).

• Make sure that tall central leaders are continuing to branch. If they are not, you may have to head back the central leaders to encourage branching along the length of the leader.

 

What to do with long, unbranched lateral branches?

• Long, unbranched lateral (side) branches should be headed back to encourage branch development. Often this means removing the end growth of a long, wispy branch back to 10 nodes.

• Sometimes this means removing a lot of growth if the problem is not caught soon enough.

• By reducing the length of unbranched laterals, a fuller, more dense canopy will develop resulting in a more desirable shade tree.
   
Long laterals at the top of the tree. Long laterals are pruned back to 8-10 nodes. Finished product is more compact and will have new branches sprouting from the remaining section of the lateral branches.
For more information: E. Gilman’s An Illustrated Guide to Pruning, 2002; American Standard for Nursery Stock, 1990; and NCSU Leaflet 406 Pruning Field Grown Shade and Flowering Trees, 1996.

 

Insects:

Mites appear to be a problem, not just in West Kentucky, but also Tennessee and Ohio as hot, dry weather continues. Mites and many small insects can reproduce rapidly, especially when environmental conditions are ideal. Their damage reduces photosynthesis and thus overall plant growth and health as well as causes leaf discoloration.

Thorough and repeated spray coverage is essential. Do not spray with carbaryl (Sevin) as it can increase in spider mite populations. Products for control of spider mites: Avid, Cythion, Hexygon, Horticultural Oil, Joust, Kelthane, Mavrik Aquaflow, Morestan, Pentac, Resmethrin, Scimitar, and Talstar. Avid and summer oil have been effective for some nurseries. Check label before use.

Source: U.K. ENTFACT 438, Spider Mites on Landscape Plants, and UT PB 1589, Commercial Insect and Mite Control for Trees, Shrubs, and Flowers, 4/02.

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Note: Trade names are used to simplify the information presented. No endorsement by the Kentucky Cooperative Extension Service is intended, nor is criticism implied of similar products that are not named. Always read product label before use.