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Gardening

I’m not spraying for spruce beetles. I wish you wouldn’t either.

  • Author: Jeff Lowenfels
    | Alaska gardening
  • Updated: May 22
  • Published May 22

Dead needles of a tree killed by spruce bark beetles in the Turnagain Heights subdivision in West Anchorage on Thursday, May 9, 2019. (Bill Roth / ADN)

I don’t need to tell Alaskans that we have a lot of spruce trees susceptible to attack by beetles. In fact, if a property in this state has a tree on it, chances are it is a spruce.

So, as you might expect, I have been inundated with emails asking about spruce beetles and using pesticides to save them. Many of these trees are big, beautiful and all too venerable, having graced the yard for decades. There is a reason for trying to save them.

The bottom line is we are not spraying our Anchorage yard here. If you want to spray, so be it. I wish you would not, but at least be sure to use formulations tested for effectiveness and registered for use as a spruce beetle control. Since the entire tree has to be covered, you should use trusted professional pesticide applicators rather than do it yourself. Only high-value trees should be sprayed. And, read up on the problem.

This is a difficult column to write. Who am I to diminish the value of your yard? Our own property has hundreds and perhaps thousands of spruce trees, many key landscape assets creating privacy and blocking views of neighbors and streets, giving needed shade for outdoor activities and providing close-in habitat for the wildlife we like to watch. I do not know what we will do if they all succumb to attacks. I only hope that the care we have given them over the years will allow some, at least, to fight off the inevitable attack.

Still, I am not advocating spraying. The insecticides applicable are not selective. And they drift, unnoticed, into other yards and into our lakes and streams. They contain label warnings against exposure to people, pets and wildlife as well as other insects. Even the professional biologist must implicitly agree that their use is not good, which must be why blanket application is discouraged.

Ah, but these trees are the backbone of our landscapes! Spraying just one or two won’t hurt, right? They are too big and too valuable to lose, aren’t they? And there is my problem.

I have dedicated the later years of my life to getting the world to stop using these types of chemicals. If I am going to be honest with myself and you, why should the size of the organism, or its placement preventing my neighbor from seeing me, make a difference? The harm to pets, wildlife and beneficial insects is the same no matter how big the plant we are trying to protect.

“Trying” is the key word here. There is no guarantee your sprayed tree hasn’t already been infected or will survive even if is coated with poison.

Jeff’s Alaska Garden Calendar

Planting time: Everything must be hardened off first. Many sourdough gardeners wait one more week, so again, there is no need to rush and get everything done all at once.

Rhubarb: Harvest some —if you must. Leaves are poisonous but can be composted.

Mycorrhizal fungi: Get some and apply to transplants before they go in the ground. Cole crops, blueberries and rhododendrons are the exception.

Dandelions: Pick or mow flowers. Don’t let them go to seed. Use a hand tool to dig them for 15 minutes every day for two weeks to try to get things under control. Clove, horticultural-grade vinegar or iron-based sprays work too, at least for a while. Nature won this one.

Delphinium defoliator: Check your plants. They are there! Spray with Bt, azamax or Neem oil. Follow directions.

Nurseries: Visit and buy. Stuff goes fast!

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