A Greener View: Japanese maples prone to brown tips on leaves
Jun 29,2007 00:00 by Jeff_Rugg

Q: I planted a Japanese maple this year. I noticed that some of the tips of the leaves are brown, but the tree looks healthy.

Do I have some kind of insect problem? One of the branches broke off.

How do I keep insects from getting into the branch?

A: Brown tips on the leaves of Japanese maples is a common occurrence caused when the plant becomes dried out due to excessive sun exposure, wind or fertilizer. As long as the brown stays within the leaf tips, I wouldn't worry about it this year. It is probably just a reaction to the planting.

Once a leaf has a brown tip, it will stay that way. If a single dry spell caused a reaction from the plant, then it will remain the same all summer. However, if the leaf becomes more dried out, the plant continues to have problems. You will need to investigate which of the above reasons is causing the problem.

If only one branch is affected, then try to figure out what occurs only on that one side. Is that the side the wind or sun comes from? Maybe that one branch was damaged during planting or shipping and it is slow in showing up.

When a branch brakes, make a clean wound by using a pruning tool or saw to cut off the stub. Don't paint it with anything and the tree will create scar tissue to grow across the wound to heal itself.

Q: A few weeks ago I attended a butterfly class at the Jupiter Library, and bought milkweed plants for my yard. They have grown quite well, but one recently had all of its leaves eaten by caterpillars.

What should I do and will the leaves grow back?

A: You can now see that attracting wildlife to your yard may have its price. Leave the plant alone and it might send out some side shoots, since every leaf node has a bud for a new stem. It could send out a new shoot from the roots, but it might just die.

If it does send out new leaves and it attracts more caterpillars, move them to one of the other plants. It is better to lose a few leaves on several plants than to lose them all. Some plants seem to do fine with the occasional defoliation and others don't recover, so the safe choice is to spread out the damage.

Q: I have many of the right larva and host plants, but I am getting few butterflies. What could the problem be?

A: In the case of movie baseball players the quote is something like: "If you build it they will come." Unfortunately, in the real case of wildlife, if you build it they may not come; however, if you don't build it they can't come. Therefore, you did the right thing, but there may not be enough nearby habitats for them to reach you. A little patience may also be necessary. Once they do find you, they may forget about you for a while as well.

More of the right kinds of plants in your neighborhood will help. Talk to your neighbors or park district to see if they will grow these plants. Adding water to your landscape may also help. Possibly, birds are eating all the caterpillars, or maybe they are dying from insecticide.

You may also need to limit your expectations. If you look at a field guide for any kind of animal, it may color the whole state to show that the animal lives there. Well, animals have habitats. For instance, a duck will only be found in the properly sized wet habitats that are large enough to supply it with food and a place to raise its young, not in every inch of the state or even in every wet spot.

Butterflies are the same way. Some like hot areas, some prefer cooler and higher altitude areas, and some like prairies. We can easily take the plants from all of those climates and grow them in our landscape. We can even grow them side by side in the same landscape in a way never found in nature. We will then get a limited number of butterflies or birds that normally feed on those plants in an unusual location.

That doesn't mean you should stop trying. Read more about the butterflies you want to attract and try to see what it is about their life cycle that is missing in your landscape. And I mean the landscape as a whole, not just the one limited by imaginary boundaries that butterflies can't see.

E-mail questions to Jeff Rugg at info@greenerview.com.

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