Master Gardeners will be at the following events:
* 9-11 a.m. Saturday, June 14: Emerson Junior High School Garden, 2121 Calaveras Ave.: Hands-on workshop on sheet mulching
* 2-4 p.m. Sunday, June 15: Stephens Branch Library, 315 E. 14th St., Davis: Water-wise workshop
* 8 a.m.-noon, Saturdays: Davis Farmers’ Markets, Central Park
Question: I have mistletoe growing in my oak tree. How do I get rid of it?
Answer: Mistletoe, Phoradendron spp., is known as a parasitic seed or plant — one that lives off another plant. A broadleaf, perennial plant, mistletoe is usually spread by birds via droppings or their feet and beaks. It also can be spread by tree pruning equipment.
Although it may seem to be everywhere, it can only survive by being dropped at an ideal point of entry: a tree’s bud, leaf base or twig. The seed needs to penetrate the woody branch for nutrients and water in order to germinate, a process that takes about six weeks. Once the green leaves and shoots are established, the plant produces its own nutrients, but it is still dependent upon the host plant for water.
The host tree and mistletoe may coexist for years. In drought conditions or if the tree is weakened by a bacterial or viral infection, the mistletoe becomes a problem by drawing large amounts of water from its host. A few growths of mistletoe on a vigorous tree may cause a portion of a branch to be stunted or die, but the tree won’t die. Numerous outbreaks throughout the tree cause serious stress, leading to premature death through secondary disease or insect infestations.
Pruning is the only way to eradicate mistletoe from a tree, cutting out the infected limbs back to strong healthy wood. Take care that the pruning doesn’t add unnecessary stress. For example, pruning during the summer months may expose the tree to more sunlight and cause sunburn to limbs that once were shaded.
Often, a gardener only notices this parasite when the tree’s leaves drop. The shiny berries contain one seed each surrounded by a gelatinous adhesive substance. Mistletoe blooms from April through December with very inconspicuous flowers among the oval-shaped thick leaves.
The UC Davis IPM website provides good information and diagrams for identifying mistletoe and how to live with it: www.ipm.ucdavis.edu/PMG/WEEDS/mistletoes.html.
Question: I’ve got moths! Where are they coming from? I don’t even have that much wool.
Answer: You may be right, but are confused about the kind of moths that are flying around your house (mine have the annoying habit of flying in front of the TV screen).
The moths you are seeing are probably Indianmeal moths, Plodia interpunctella. You will need to search your pantry and other food storage areas carefully. Another likely source is that bag of bird seed you got on sale and haven’t gotten around to putting out for the birds. You will find tiny holes in plastic bags, and cobwebby material in food boxes, where the moth larvae have chewed their way out and are now flying around your house.
A vacuum cleaner is a good way to make sure you have picked up every bit of frass (droppings) and even eggs that might be left behind. Inspect all the food containers, including unopened boxes that may have tiny holes indicating entry points for the larvae.
You can still feed that bird seed to the birds. You probably will want to discard any other food products that have become infested. For more information, go to www.ipm.ucdavis.edu/PMG/PESTNOTES/pn7452.html or pick up a “Quick Tips” on moths next time you come to the Master Gardener table at the Farmers Market. (The moths that attack wool are much smaller. You can also find out about them at the IPM site.)
— Send questions, addressed to the “Garden Doctor,” by email to [email protected], voice mail to 530-666-8737 or regular mail to UCCE Master Gardeners, 70 Cottonwood St., Woodland, CA 95695. Be sure to include your contact information because any questions not answered in the Garden Doctor column will be answered with a phone call or email to you.
You can request the Yolo Gardener newsletter, delivered by email, and learn more about the Master Gardener program in Yolo County at http://ucanr.edu/sites/YCMG.