Ask the Gardener: Plant ID, knotweed, tree selection and more

Posted on: September 14, 2019 | Written By: Doug Oster | Comments

Everybody Gardens editor Doug Oster gets asked a lot of questions. A lot. And he doesn’t mind offering gardening advice. But rather than just limiting those answers to the person who asked, we thought it might be a good idea to share that wealth of knowledge with everybody.

There are three ways to send in your questions:

  • Email
  • Submit your question on our “Your Garden” section of our site
  • Send us a message on Facebook.

(The questions may be lightly edited for grammar/clarity/etc.)


Question 1: Plant ID

Carol: Do you know what this might be? The flowers never open and there are spiky pods on the plant. It sprouted up along the house under a bird feeder.

Doug: That’s datura, one of the many plants called moonflower. It’s an annual, and the seeds in those prickly pods are poisonous.

Question 2: Knotweed

Joyce: How do you get rid of Japanese knotweed? We have cut the stalks, used Bush kill and Roundup, and it keeps coming back.

Doug: There’s only one way I know of to get rid of knotweed, and it’s not easy. It’s called continual top kill. Once a week during the season, cut the knotweed plant to the ground. Eventually it can’t continue as the roots are fed from the foliage. I got rid of some, but it took two years. Wish I had better news for you.


Question 3: Tree selection

Janet: This is a picture of my tiny front yard. I had the beautiful maple removed because it was too big for my yard, and its roots going everywhere were concerning. Our HOA has approved a Japanese maple as a replacement. Since there are many, many varieties, I’m wondering if you could recommend a Japanese maple (that would grow as a tree, not a bush) that would be appropriate for our small yards. Would Emperor be OK?

Doug: Emperor is a good one, but if it was me, I would look around a little to find something more unique. There’s nothing wrong with Emperor. It’s a reliable, pretty tree, but there are so many different Japanese maples out there with different colored bark and foliage.

You’ve got two months or more to decide. This is what I would recommend: go to a good nursery and look at the trees they have there to get an idea. Tell the person how big you want it to get at maturity and take it from there.

Here’s an idea of what’s available. The key to doing this is having fun to find the right tree for you.


Question 4: Tree issue

Beth: Can you offer me some advice on how I can treat my Poinciana tree? It has lost bark off the trunk and it looks like holes are bored into the trunk. It’s now losing leaves. Can I save it?

Doug: The best course of action is to call a certified arborist to look at the tree. They will come for free and inspect the tree, then tell you if it can be saved and what the treatment would cost.

From the picture, it’s not looking good, but maybe the arborist can help. I use Davey Tree, they have offices all over the country.

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