Birch had borers, but crown looks better than the middle?

[Minneapolis]

IMG_20170603_153955

• Minneapolis
• Jun 3, 2017
• 1

Our whitespire birch, borer damage. Crown is not dead. Hoping for recovery.

A question for you. My reading said birch borers always damage the crown first. Our 6" diameter whitespire birch had borers yet the crown looks better than the middle branches. But everything is thin in the upper two thirds.

I hope the crown still having leaves is a good thing and bodes well for recovery. What do you experienced arborists think?

It has had one imidacloprid treatment drench last August. I can see the winding calluses on the upper trunks so I know it is borers.

I have included some photos of our birch.

 

[Minneapolis]

IMG_20170603_154034

• Minneapolis
• Jun 3, 2017

WHitespire birch, borer victim, crown view.

 

[JD3000]

Continue treatment this year. An august application of last year would carry over to this spring but the timing isnt optimal. Agrilus borers are emerging, feeding, and laying eggs in most regions by now. Imidacloprid is an excellent and inexpensive treatment option.

Managing stress for white birches is #1. Mulch as wide as you can and water when needed this summer when the heat hits. This will very much help the tree recover and keep some borers from being attracted to the tree.

 

[Minneapolis]

Thanks, JD3000.

Is it unusual to have borer damage that thins the top third but does not kill the crown? I would think that having the crown still alive, even though it is thin, is a good sign and will help suck up nutrient to the top and heal over the borer galleries in the cabrium layer. Am I right?

Also, should I drench before August? I read somewhere that for trees larger than 4 inches you should wait until August for the imidacloprid drench. I wonder what the logic was in that?

 

[JD3000]

Thinning upper canopy would be normal for this borer. Drench soon or have a pro do it. Our products are more concentrated and dosage is important.

Focus on cultural stress mgmt.