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Cicadas and Ivy: can they damage your landscape?

Plants that some folks call weeds, and insects that are sometimes called "locusts."

Working on your landscape and garden can get pretty darn confusing! Later in this column, I'll address a concern that Ivy and Wisteria are no more than weeds. But first, let's get ready for that invasion of non-locusts: cicadas!

By mid-May most of the eastern half of the United States will be familiar with those noisy little critters known as 17-year cicadas. Literally billions of these insects will emerge from the ground, begin to "sing" then mate and die. That's assuming they manage to crawl up a tree, fence or post before they become a tasty snack for your pet cat or dog, or for any wildlife predators.

Let's address the most important issue on most people's minds: cicadas are harmless to humans, pets and other animals. They cannot sting you or bite you and they are not poisonous if ingested. I'm told that if you eat a cicada as soon as it emerges from the ground and before the new shell hardens, it will taste like cold asparagus. Uh huh. I'm willing to take someone else's word for that, but it's good to know that Kitty and Fido will survive their cicada buffet!

However, delicate trees and shrubs CAN be damaged by cicadas. The damage done by 17-year cicadas is far less catastrophic than that of "real" locusts with which they are sometimes confused. Cicadas can damage your landscape in two ways: when the female lays eggs in slits in tree branches, and when the "nymphs" (larvae) sustain themselves during their time underground by feeding on the tender roots of plants.

How can you protect your trees from cicada damage? The three main choices are covering, spraying or pruning.

Small trees can be covered with very fine netting such as cheesecloth, secured around the trunk to prevent the determined critters from climbing up. You'll need to keep them covered from the first sign of emergence until the "invasion" is over.

Spraying with insecticides is an option that can help to reduce damage, mainly by acting as a repellant that fends off the females before they lay their eggs.

If you notice twigs with fresh slits in which eggs have been laid, you can prune them and destroy them before the eggs hatch. When you prevent egg-laying or remove damaged twigs, it follows that you will also lessen the likelihood of root damage from the resulting larvae.

Here are some useful links with more cicada information.

Recently I was taken to task by a reader of this column over an answer I had given to a question e-mailed to me by another reader. In that original question, I had been asked if there was something other than English Ivy that could be trained up a fence and that would withstand direct, hot sunlight. In my answer I suggested that Wisteria could be a good alternative.

However, I then received an e-mail telling me that both English Ivy and Wisteria are considered "noxious weeds" and it was wrong of me to recommend any plant that could adversely affect the eco-system.

Now, I'm always happy to receive e-mail messages, even from people who disagree with me! Indeed, I was probably remiss in failing to mention that Ivy and Wisteria - if leftuncontrolled -can spread rapidly and become a nuisance, even choking out less aggressive flora.

However, I happen to like both Ivy and Wisteria; certainly not everywhere and only in appropriate locations andcircumstances. All plants and shrubs should be carefully monitored, trimmed and - where necessary - cut back. Of course, this applies particularly to plants that have the potential of spreading rapidly. Whenever we plant anything, we have the responsibility of being good stewards of our landscape.

So let me add this to my original answer: Yes, English Ivy and Wisteria can be considered weeds, and, if left unchecked, can spread and overpower other flora. You will need to keep an eye on them and make sure they don't get out of hand. But even if they are "weeds" I happen to think they are attractive and can be a viable addition to your landscape under the right conditions!