Saving a Japanese maple, killing poison ivy

japanesemapleI have a 25 year-old Japanese maple that got all of its leaves frozen off last spring. It got more leaves but there were not as many or as big. Some branches are bare. What do I put on it this spring so those leaves come back? I did nothing to the tree last season. So what do I do this year?
The phrase, “Pray a lot” comes to mind. If you truly did nothing, which includes watering, the tree was beaten up by the heavy freeze and kicked repeatedly by not being watered during a drought.

Last spring’s flip-flop of 85 degrees in March and 18 degrees in April caused a great deal of damage to plants. Japanese maples have always been garden divas and the weather extremes hit them especially hard all over the state. It is more concerning that it did not re-leaf well and that there are dead branches. Others did. But let’s not talk too much about what should have happened.

This spring, by the end of May, remove the obviously dead wood. Prune it back to where it joins live wood with twigs or branches with leaves. Consider getting a soil test and following the instructions. But you are not going to use the full amount on a damaged tree. It could be too much. You should use your nitrogen recommendation at a half dose this year. The phosphorus and potash, if they are required, can all go on. If the soil pH needs to be adjusted, that can happen. But nitrogen can cause burning if it is too much for the weakened tree.

See how the tree responds this year. Mulch the tree with 3 inches of wood chips or other organic mulch. And water when it is dry. This is the key to recovery. No water means no growth. To buy a soil test self-mailer for $25, go to <> and follow the link to the MSU Bookstore.

I have Boston ivy as a ground cover. I got a poison ivy rash pulling some weeds there last fall. What do I spray with to get rid of the poison ivy that is mixed into the Boston ivy? I want to do this real soon.
All aboard for the bad news express. This is not an easy problem to solve for a couple of reasons.

Basically, poison ivy and your ivy are both broad-leafed plants. That means that an herbicide kills broad-leafed plants will kill all of them, if sprayed. If you use a nonselective herbicide, it’s the same thing. There are no “bad plant” herbicides. That means that your herbicide is going to have to be selectively applied to only the poison ivy.

Use a nonselective herbicide and apply it only to the poison ivy leaves with a foam paint brush. This is slow, tedious and back-breaking work. Then you will have to go back all during the growing season and look for more poison ivy.

And you can still get a rash from dead poison ivy because it still has its resinous oil on the dead stems.

You are not going to use weed killers until the poison ivy is vigorously growing. That means a delay until mid or late May. If the nonselective herbicide is absorbed into the leaves, there have to be green leaves on a growing plant. You are trying to get the maximum amount of herbicide to be absorbed. Consider working in the area with rubber gloves. Also consider several of the poison ivy products that protect you like Ivy Bloc or Ivy Shield. There is a wash to use after being in the garden that removes poison ivy oil from skin called Tecnu.

Learn to detect poison ivy rapidly and remember that if a bird can sit above the garden on a branch, it can return poison ivy seeds to you after eating the delicious berries in the fall.

Contact Gretchen Voyle, MSU Extension-Livingston County Horticulture Educator, at (517) 546-3940.

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