ORNAMENTALS AND TURF
From: Steve Frank, Extension EntomologistNotching on Redbuds by Bees
Leaf cutter bees in the family Megachilidae are actively notching out small pieces of leaves from redbuds and other trees. They also attract attention for tunneling into soft rotten wood and hollow or soft, pithy plants stems like roses. They make their nests in these hollow tubes and line them with leaf fragments. Leaf cutter bees are of much more of a benefit than a pest. Try to convince clients of this but also most insecticides are either not labeled for bees or ineffective since the bees do not eat the leaves. Many people are more concerned about the bees tunneling in their roses which can be prevented by sealing the ends of branches after pruning. Overall these are an important native pollinator that should be protected and even encouraged.
More pictures: http://ecoipm.com/
Information sheet: http://www.ext.colostate.edu/pubs/insect/05576.html/
Catalpa Defoliation
I had a report this week that a catalpa tree on campus was completely defoliated by sphinx moth caterpillars. Caterpillars in general can make short work of trees when they really get going. Look for chewing damage and frass on leaves. If you find a few big caterpillars you could pick them off. It is probably late at least in Raleigh to implement much control since it sounds like they are about done. These big beautiful caterpillars become big beautiful moths. The adult ‘hawk moths’ hover around flowers feeding on nectar and are often mistaken for humming birds.
From: Lee Butler, Extension Assistant, Plant Pathologist
Summer Solstice Welcomes Brown Patch
June is in full swing and so is brown patch in tall fescue lawns and landscapes. Brown patch, caused by the fungus Rhizoctonia solani, is the most common disease in tall fescue during late spring and throughout the summer months in North Carolina. Brown patch infections can start as early as April in some years with full blown outbreaks occurring by late May and early June in most years. As the name implies, symptoms are brown to tan areas of turf that are roughly circular patches that range from a few inches to several feet in diameter.
The two most common mistakes managers of tall fescue make are fertilizing too late or too much in late spring and over watering. Tall fescue should not be fertilized after the first of May, unless you are using ultra low rates (< 0.25 pound N/M) with iron for a color effect. The recommended amount of nitrogen on tall fescue per year is 3 to 4 pounds per 1,000 square feet. Most people will apply a pound or two in the fall and a pound or two in the spring. When in doubt, submit a soil test to ensure you're feeding your lawn the right nutrients at the correct amounts.
Watering should be done only as needed to prevent drought stress. When you do apply irrigation, do it deep and infrequent instead of watering every day. It is a common mistake for homeowners to set their irrigation system on a schedule and forget about it. Remember, fungi love water and if you over water, you're giving the advantage to the fungi, not the turfgrass. The ideal time to water your lawn is in the early morning hours before sunrise. Irrigating during late afternoon or early evening is the worst thing you can do because this extends the leaf wetness period, however brown patch will love you for it!
Need help knowing when and how much to water your lawn? Try out our online water management tool at the following link: http://turf-ims.ncsu.edu/.
For more information about brown patch, including control recommendations, please visit the following link: http://www.turffiles.ncsu.edu/Diseases/Brown_Patch.aspx.
Be sure to check out other posts from NC State Turf Pathology (http://ncstateturfpathology.blogspot.com/).
For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.
