Struggling Birch trees

Asked August 23, 2019, 7:59 PM EDT

Is there something happening to the birches planted here (I'm in Eugene). I've been wanting to gather some, and I am noticing that they are nearly all looking 'peaked' as my grandma would say. Some look like the tops have died, some have a couple large fronds dead, some all the strands look like they are slowly dying. The first could be growth habit that I hadn't noticed, the second could be wind damage or a bug. The third could be that fewer people water their lawns or a new disease. However, the last two seem much more prevalent this year, so I thought I'd ask if something new is happening.

Lane County Oregon

2 Responses

The birch borer is causing a great deal of damage the past few years. The first sign of infestation is flagging branches with sparse, stunted and yellowing leaves at the tree canopy, she said. Twigs will fall and eventually the branches lose their leaves.

There's no easy way to defend against the pest. Besides cultural practices like mulching and watering, which can help fend off the insect if the tree isn't yet infested or is early in the infestation, the only solution for control is chemicals.

If this is the choice it is probably best to have a professional do the work as misapplication can kill both the bees and the tree..Systemic pesticides should be avoided if there are attractants to pollinators nearby.The adult bronze birch borer looks like a tiny, long football and is olive to brown with coppery metallic wings and body. It lays eggs under loose pieces of bark at the top of the tree. After about two weeks, the eggs hatch and the larvae bore into the cambium layer, where water and nutrients move around. As the borer feeds, the frass it produces plugs up pathways. It feeds for two years, during which it does considerable damage, and then emerges. By the time you see the D-shaped holes, damage can be significant.

This information is from Nicole Sanchez, a horticulturist with Oregon State University Extension Service.

Thank you! It's really been bugging (heh) mel. Extremely sorry to hear about the birch borer, but happy to know what is going on.