Ask a Question
Notify Me On Question Update
Email this Question
Is There Any Way To Eliminate Borers That Leave What Looks Like Sawdust At The Base Of Our Aspen Trees?
Rate This FAQ
Your aspen trees have aspen borer, an insect in the long-horned or round-headed beetle group. This insect problem is very common. The injury is caused by the larvae feeding on the inner wood of the trunk. Their tunneling weakens the wood and allows the invasion of canker and decay fungi. Borer wounds typically “sap” or “bleed.”
Aspen is an attractive host for the insect, especially when the aspen tree is already under some kind of stress or decline. Common stresses for aspen trees in our area are iron deficiency (yellow leaves), poor watering regime (too much or too little), aspen leaf spot (fungus causing leaf spot - common following wet springs or when sprinklers water the leaves of trees), oystershell scale (insect that feeds on limbs and trunk of tree, sucking out sap), and aspen borer (beetle larvae that bore holes into trunks of trees). Aspen is not well adapted to living in the valley areas. They do much better in the mountains.
Suggestions to reduce aspen borer problems:
* Don’t plant aspen, select another tree species that is well suited to our valley growing areas and not as susceptible to insect injury.
* Grow aspen in a grove with continual renewal of trunks rather than as single specimen trees in your landscape. Aspens have a strong ability to sucker and send up new shoots. Remove aspen trunks when signs of borer injury are observed (sap running down trunk, accumulation of sawdust at base of hole or tree) and allow new trunks to fill in the open spaces - aspen are quick growers.
* Keep aspen trees as healthy as humanly possible - treat with a chelated iron product in the spring to reduce iron chlorosis, prevent sprinkler water from getting onto leaves (promotes aspen leaf spot disease), prune out dead and dying limbs, water properly (water as a tree, not your lawn - this means infrequent, deep waterings), remove trunks infected with borers as soon as they are observed. A healthy, vigorous tree will resist borer attack.
* You cannot remove the damage that the borers have already done. You can help (sometimes) reduce further damage to the injured trunk and others in the area by well-timed insecticide treatments to the trunks. This is costly, time consuming and involves some risks (pesticides should always be used properly - follow the label directions and wear appropriate protective clothing; there may also be environmental safety concerns).
* You must treat before the adult beetles lay their eggs in the late spring through summer. Once eggs hatch and larvae bore into the trunk, the damage is done. Chlorpyrifos (Dursban) insecticide products labeled for shade trees are the recommended treatment. Apply a spray that drenches the main trunk of the trees every 3-4 weeks from May-July in northern Utah.
Submit Your Suggestion
Other Questions In This Topic
- I sodded my back yard 3 years ago with RTF. It has not held up well, especially in the higher traffic areas where it is completely dead. Any suggestions?
- I have tall thin Junipers in my backyard. They resemble a Hollywood Juniper but I am not sure of their species. They are 25 years old and have begun to look like they are dying, the needles are turning brown and falling off. Is there anything I can do to save them?
- There are brown spots in my lawn every summer, some are round and others are ribbon shaped. What can I do to prevent this problem?
- I have rings in my lawn that are about two feet wide. I suspect they are fairy ring, but the description for fairy ring doesn't quite fit. The inside of the circle is not lush and green, it looks the same as the rest of the lawn. There is just a semi-dead cirle surrounding good lawn. Do you have any help for me.
- I have raspberry plants that have grown to where they will be bearing this summer. And wouldn't you know it, we are moving. I want to dig them up just before we move, say in middle to late February. Can I put them in the same type of packaging they came in when purchased and then plant them in the spring when the ground thaws. Will they still bear fruit this year?
- I have many large 20-25 feet scrub oak trees on my property. I would like to thin and prune them from the tops in order for them to look like the lower scrub oak I have seen in the area, about 10-15 feet. How low can I cut them from their tops without injuring them and what is the best time of year to do so?
- I've neglected to do my "last mow" up to this point. We've already had several nights of light frost. My grass is long but I worry about causing even more damage by mowing at this late juncture, mid-November. Are there any risks to mowing grass after the first few frosts?
- How do I prevent aspen sprouts from coming up in my lawn?