What is killing my shrubs?
Question:I have some nice shrubs on each corner of my house. I'm not sure what they are, but I've seen them referred to as a "Smoke Bush". They can grow quite big and have purple leaves.
Last year, I lost one of them suddenly. It started with one branch going dead, then the whole plant.
This year the rest of them are going south on me.
I dug one up last night and found the trunk had a ton of holes in it and I found several worm around it. They appeared to be normal old earthworms.
Are the worms killing my plants? They don't seem to be doing damage to any of the other shrubs or plants. These shrubs have been there for ten years with no problems.
Located in the Minneapolis area.
Answers:
Grasshoppers!! try to sprinkle 7-dust powder on them...
The worms had nothing to do with it. The holes in teh trunk are what you need to worry about. Take that shrub you dug up and dissect it. Take a few picures of anything you might find that looks out of the ordinary, and take it to a local plant nursery. They should have better advice than you'll find here, and the stuff you need to keep your plants healthy.
P.S. I think your shrubs are called "Burning Bush"
Will grow best in a sunny location with well-drained soil but it also can be useful in dry, rocky soils . Smoke Bush definitely has year-round interest with its summer and fall foliage color and spring "smoky" blooms!
Soil Preference: This plant will tolerate drought and some salt and will grow in dry soil but prefers well-drained/loamy, sandy or clay soils with a pH of acidic to alkaline.
zones 4-7 (what zone is Minneapolis?)
Light Requirements: Full sun
Pests: Leaf roller may mine and roll leaves in May
Earthworms shouldn't bother them
Diseases: Leaf spots, scab, Verticillium Wilt, stem canker
I would try other bugs. Worms don't bother much...but other insects can. They love to munch on anything. If they are where the roots are maybe they are eating at that causing the roots to die, and the rest of the plant!
Smokebush are generally pretty tough and far too beautiful to lose.
The number one killer of plants I see as a landscaper is over-watering. The holes you see could be caused by insects, but maybe aren't the problem. It's difficult to know without actually seeing the plant and the area they are planted in. Were the holes on the main root undergound?
It could be simply rotting out because the soil stays too wet, then insects and worms are taking advantage of the free meal of decomposing wood by digging holes in it.
Take stock of how many hours of light they receive in a day, how much water they get, and any other factors such as how many inches of mulch they have, are there rain gutter downspouts nearby, do they get runoff from a sidewalk or driveway, etc.
Like your first respondent suggests, dissect it, take lots of pictures, then take all the information to a reputable nursery.
Better yet take the whole sample to your extension service. State Extension is a wonderful and totally under-utilized resource. I'm not familiar with where to contact them in Minnesota, but here in SD they are based at SDSU in Brookings and have agents in every county. I'm sure they do the same in MN.
the holes in the trunk sound like wood-boring beetles of some sort. 'smoke tree' is what the bushes are called, cotinus coggygria sounds like the species you have. verticillium wilt is what they are most prone too, tho. well, sounds like it's a lost cause, in any case. you should take one to a garden center for a definitive diagnosis. have the person come out to your car, as he/she will not appreciate you bringing a disease or pest into their store! if it's v. wilt, just don't plant any more of them. if it's beetle, you'll want to take measures to spray your other bushes and trees to prevent further infestation. february is the time to do this.
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