Fall is a favorite time for some garden pests

Published 12:00 am Friday, September 2, 2011

By Darrell Blackwelder
For the Salisbury Post
SALISBURY — September is a transition month when most people are burned out with vegetable gardening. Lawn care and maintenance is a big part of September chores, but homeowners have other questions. Below are a few questions that you may have pondered.
Q: I have an azalea that is coated with small white moths flying around. They cloud up when disturbed and then go back to the plant. What are these and how do I control them?
A: These are whiteflies, which are neither flies nor moths. They can be a problem with azaleas, gardenias, tomatoes and other plants. These insects suck the sap from leaves, leaving a residue that can cause a black mold (sooty mold) to develop. Oil sprays or insecticidal soaps will control them. Cold weather usually eliminates them, but some have adapted to colder climates in our area.
Q: My broccoli, collards and other cool season vegetable crops have little green worms that are eating them. What can I do to eliminate them?
A: Worms and other insects are at their peak population in the fall. Sprays with Bts (Bacillus thuringiensis), Dipel or Thuricide will control these pests. These sprays contain bacteria that kill the insect but are not harmful to man. These types of sprays work slowly so patience is a must.
Q: I have an oak tree that bleeds continuously during the summer. It has done this all summer long. The foliage looks good and otherwise the tree looks healthy. Is it borers and what can I do to stop them?
A: The problem is most likely a condition on the tree called slime flux. Slime flux is unsightly seepage of sap from the trunk of shade trees. It occurs in apple, birch, elm, hemlock, maple, mulberry, oak, poplar and willow. In North Carolina, slime flux is very common in large, mature, landscape oaks, tulip poplar and elms. This disease is not normally a serious problem if the tree is otherwise healthy. Go to http://www.ces.ncsu.edu/depts/pp/notes/oldnotes/od8.html for more complete information.
Q: My irises I planted in the spring have done very well despite the heat of the summer. Now I have one that is in full bloom. Is this normal?
A: There are some iris cultivars that will re-bloom in late summer and into the fall. The recent cool weather along with earlier rains may have sparked the plant to re-bloom. Go to http://www.ces. ncsu.edu/depts/hort/hil/hil-8506.html for more complete information about bearded irises.
Darrell Blackwelder is the County Extension Director with horticulture responsibilities with the North Carolina Cooperative Extension Service in Rowan County. Learn more about Cooperative Extension events and activities by calling 704-216-8970, Facebook or online at www.rowanextension.com