complete turf and landscape blog

Ward Parkway in Kansas City is considered the best display in George Kessler’s boulevard system, developed in the early 1900’s.  There is, however, a critical plant health issue along Ward Parkway, pine wilt.  Not only is it severely degrading the parkway landscape, it is also a huge concern for anyone with pine plantings on their property. Because they grow quickly, Scotch and Austrian pines are planted very frequently in home and commercial landscapes to create a screen between properties.  If these trees die the screen disappears and property values can plummet!  At last count 57 mature pines have been attacked and are dying along Ward Parkway between Wornall Road and 55th Street.  Clearly the landscape of this area is being altered considerably.
 The Pine Wilt is spread by the pine sawyer beetle. The beetle begins feeding on the twig of a healthy Scotch or Austrian pine and creates an injury.  This triggers immature beetles (nematodes) that live within the pine sawyer beetle to exit the body of the beetle and begin eating the tissue of the pine tree.  In very short order (two to four weeks) the immature nematodes have killed the tree and for the rest of the season eat the dead tree to sustain themselves.  Later in their life cycle thousands of the now mature pine sawyer beetles fly distances of up to one mile to find a new, completely healthy host to start the cycle over.

What can be done?

First I recommend considering treating any pines of value on your property with a preventative insecticide.  Fair control has come from Greyhound, an injectable insecticide that has reduced pine by about 60% – not a number to brag about but depending on the tree’s value, may be worth the gamble. Secondly  if a tree becomes infected it is essential that it be removed immediately before the thousands of nematodes feeding within mature and spread to otherwise healthy neighboring trees.
Not a pretty picture to be sure.  These trees make up 10-25% of the planting in landscapes today.  It really will require a measured effort to prevent a tremendous blight- and prevent you from having to see that goofy neighbor, in his hot tub, all the time.

During dinner the other night my wife offhandedly mentioned to me that she saw a rabbit hopping down the driveway – “with a mouthful of flowers”.  I was outraged!  As I further interrogated her she became more annoyed.  “What color were the flowers?’  “Were they round or skinny?”  Finally she refused to answer any more of my questions.

The lessons learned from this episode are twofold.  First it is so important for everyone in the family to help scout for pests.  Annual flowers are expensive and are their maintenance is very time consuming.  Secondly it reminds one to be aware of what plants in their garden are susceptible to rabbit damage and what remedies are effective when they are turning your garden into a salad bar.

The following is a great link to an article by Richard Jauron, Department of Horticulture on the Iowa State University Horticulture website.  This page lists plants that are both susceptible and resistant to rabbit damage.

http://www.ipm.iastate.edu/ipm/hortnews/2002/6-28-2002/rabbitdamage.html

If your plants are on the susceptible list there are several options for dealing with the critters as well.  While my grandfather had an extremely effective solution, usually ending with a stew, our urban environment requires dealing with them in a more conventional manner.  Garden stores offer many products with varying degrees of effectiveness and longevity.  The most effective seem to be sprays that produce a foul taste or pepper based oils.  While both of these are moderately effective they require reapplication after about four weeks.

The short story is there is no “magic bullet”, at least not yet, for rabbit control.  If the sprays do not work, the gardener’s only solution may be to remove the plants and put in something on the “rabbit resistant” list.