Gardening

Invasive trees and varieties prone to infestation are on the way out. But what should they be replaced with?

European Bird Cherry, Sally Gibert, invasive plant, invasive plants, chokecherry, may day tree, mayday tree, prunus, prunus padus, prunus virginiana

Spruce bark beetle kills and mayday trees are in the news these days, and I get lots of questions about them. An email from an old friend covers quite a few of the questions I have been getting this summer concerning these trees.

My friend has a beautiful mayday tree that grows outside her window and gives her much privacy. Alas, her condo association wants to take the tree down despite the shade, the privacy and all the birds it affords. They also want to take down healthy spruce and larch trees because “they might fall down in 10 or 20 years.”

So here are her questions:

First, how important is it that every mayday is taken down? Is there a way to trim it to keep it? The city planted lots along the coastal trail, but I don’t see any of them coming down. Is there a program for taking down mayday trees citywide?

Well, the mayday tree, or Prunus padus, also known informally as European bird cherry, is an extremely invasive plant because birds eat the berries and spread them all over the place. No matter that they produce a fantastic display of fragrant flowers and provide cover, etc. They should not be planted and, I hate to say it, existing trees should come down. They are that invasive. You can’t trim them to make them “safe,” either.

Next, does the muni have a preferred list of trees to plant in their stead?

There may be a list, but I am sure it would include these eight species: spruce, alder, birch, western hemlock, yellow cedar, quaking aspen, tamarack and black cottonwood. Personally, I would take black cottonwood off that list.

If you want a list of trees that are available and make it in Anchorage, check out the excellent webpage from local nursery Faltz. Or take the online tree tour of UAA. You might want to even take the actual tour. Finally, and especially if you are not living in Anchorage, check out the Landscape Plants for Alaska website, which has info on more than 350 trees, shrubs and vines.

[The spruce beetle invasion’s exhausting toll on Southcentral Alaska property owners]

OK next, some cities have a rule that if you take one tree down, you need to plant a tree to replace it. Do we have a program like that?

I am not aware of such a program. It is a great idea, however. Can you imagine what Anchorage — or Fairbanks — would look like if even developers had to replace tree for tree? Once our city government stops all its internal bickering, perhaps the mayor and the Assembly will come together and pass such a law. Trees make this city. Politicians don’t.

And finally, my friend asks, as do all those with similar questions, what trees would I recommend as a replacement for her? Which might grow the fastest? Are there any flowering trees — pear, apple, cherry, mock orange, whatever — that might be pretty and not have too many problems like bugs or infestation?

Ah, it always comes down to what tree do I think would be the best replacement! I view tree purchases the same way I view combs: you need to buy them yourself as only you know what you like.

Oh, and I wouldn’t cut down healthy spruce and larch trees because they might fall down sometime in the next 20 years. That is ridiculous logic.

In this instance, there is a condo association making the decision about a replacement tree. I would rule out crabapple and other fruits as someone will complain about yellow jackets and wasps. Mock orange will get to 12 feet or so if there is full sun all day, but often get thrips. Cottonwood grow fast, but who would ever plant such a messy tree? Spruce grow very fast. Such a tree is probably not a good idea in front of a window, however.

How about a nicely shaped birch sapling? It will grow fast. Birches can be shaped. They are “clean” other than leaves and small catkins falling. The bark is a treat. They attract and support birds and can hold a feeder or two. Best of all, there shouldn’t be any problems with the condo association. Who doesn’t appreciate a birch tree?

Jeff’s Alaska Garden Calendar

Picnics in The Garden: The Alaska Botanical Garden has too many things going on to list here. Check them out at www.alaskabg.org. The nursery is open. New hats, shirts and more are in and, The Garden looks fantastic!

Master Gardener Plant Sale: Saturday, Aug. 13, 10 a.m.-3 p.m. at Alaska Botanical Gardens Parking lot, 4515 Campbell Airstrip Road. Perennials that are not available anywhere else, House Plants, Classes, and Ask a Master Gardener Table.

Wind: Now you know why you need to stake or otherwise support hollow stem plants — delphiniums, snap peas, etc.

Jeff Lowenfels | Alaska gardening and growing

Jeff Lowenfels has written a weekly gardening column for the ADN for more than 45 years. His columns won the 2020 gold medal at the Garden Communicators International conference. He’s authored several books on organic gardening, and his latest book, "Teaming With Bacteria," can be pre-ordered on Amazon. Reach him at jefflowenfels@gmail.com.

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