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
- When will my flowering shrubs bloom, and when should I prune them and my evergreens?
- I made the mistake of fertilizing my newly planted trees. I had heard that the salty, clay soil I have needs iron useable for the trees. I used chelated. Anyway two of the trees, a candian red cherry and a zelkova tree have dry crispy leaves on the north side of the tree. We have had very hot, windy weather. I have two other canadian cherries that look fine.
- 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?
- I bought an azaleas from costco. How do I take care of it?
- How do I prune my roses?
- I have a scarlett red maple. It's about 8 years old and last year the leaves didn't get very big. This year, it hasn't even began to bloom yet although, It has tiny buds. I noticed that the bark in some places peels off very easily. Under the bark, it looks like there may be some black flecks (maybe bug feces). I only noticed one little red colored bug under where I peeled the bark. I don't see any other bugs anywhere, even at the base. Do you think it could have a disease or bugs? I am going to put some fertilizer steaks around it and pour some Bayer Advanced tree and shrub insect control around the base of the tree. Is it too late to spary it?
- I am wondering if I have some sort of fungus in my lawn.
- I want to make a portion of my yard a 0scape environment. How do I prepare the area so that the grass/weeds to not take over? What tools will I need to make the soil acceptable? What time of year is best to plant new plants for this area?