Thousand Canker Disease of Black Walnut and Walnut Twig Beetle

50240851The title sounds like something straight out of SCI-FI, but it is a deadly disease.  I was asked by Whitney Cranshaw, Professor of Entomology, Colorado State University if I would mention it in one of my blogs.  The subject came up in one of our Master Gardener Courses and how important it is to disseminate the word on this serious disease.

In the past decade there has been an increasingly number of Black Walnut (Juglans nigra) falling prey to the Thousand Canker Disease.  The Walnut Twig Beetle, though native to North America, is ususally connected with the Arizona walnut tree.  The Walnut Twig Beetle, though not harmful to the Arizona walnut tree, is exceedingly harmful to the black walnut trees in the eastern half of the United States.  An infestation of the Walnut Twig Beetle in the East, where the tree is native, would be a tremendous blow to the lumber and black walnut nut industry. Continue reading


Mite Alert, Mite Alert!!!


                                                                 Clover Mite

You know Spring is getting closer when we start to talk about bugs.  Our El Paso County Horticulture Agent asked all the Master Gardeners to disseminate the word about possible problems with grass mites.  The warmer weather we have been experiencing has started the Kentucky Blue Grass to come out of dormancy.  This is a prime-time when turf can be killed by mites.  We have had a very dry winter here so far and without proper winter watering of our turf grass, there is the possibility of damage done by the grass mites.

There are three major mites that damage our turf-grasses here in Colorado and they are Clover mite, Banks grass mite and Brown wheat mite.  Mites thrive during a dry environment like we are experiencing now.  I can’t say enough, but winter watering is vital to ensure our turf-grasses are not attacked by these mites.  A large number of our phone calls to our Master Gardener Help Desk last Spring were turf related.  Complaints were, grass is not greening up even after I watered and fertilized.  The major cause was winter dessication and or mite damage.  Now is the time for prevention, not after the turf has already sustained some damage.

Mite damage is commonly mistaken for turf winter kill.  The mites become active as the temperature warms and begin to attack areas that are drought stricken.  Mites are hard to see with the naked eye since they only the size of a pin head.  For more information on mites and how to control them check out  The photos you see came straight from the CSU fact sheet.


                                                                     Banks grass mite


                                                              Brown Wheat Mite


                                                             Damaged turf grass