In landscapes across the region, homeowners overly zealous with the mulch at the base of trees are creating what Chris Daeger calls the "toilet plunger effect."

"It looks like a toilet plunger," explains Daeger, manager of the Stanley M. Rowe Arboretum in Indian Hill. And it's unhealthy for trees.

Over-mulching can promote trees with shallow roots that can blow over in the wind, Daeger says. And, the same organisms that break down the mulch can eat the bark.

It's good to mulch around the base of landscape trees, Daeger says. But keep the mulch low.

"Don't mound it. You just need a couple inches, at most, even when you put in a new tree."

How to avoid some other tree mistakes? Daeger advises:

Don't top off trees. That's the practice of shearing the tops of mature trees.

"It's a great way to kill a tree," Daeger says. "When you top a tree, you're cutting parts of a tree at a location that does not have a natural ability to close and heal up".

Instead, prune to a side branch one-half the size of the original.

If a tree is growing close to a power line, Daeger says to call a professional.

Do remove wire baskets - and burlap - from the roots when you plant new trees.

The basket can choke the tree as it grows. Daeger recommends removing the sides of the basket - and pulling back the burlap - after you place the tree in its hole.

Avoid wrapping trees or enclosing them in tubes to protect them from rabbits, deer or damage from trimmers.

You are creating an environment inside the wrap or tube that could harm the tree or create a home for fungus, mold and rodents.

If a tree comes from the nursery wrapped for protection during shipping, remove the wrapping after planting.

Daeger suggests using a shallow layer of mulch as a buffer from lawn equipment. If you are concerned about rabbits, try a circle of chicken wire around the tree.

If deer are a concern, taller fencing will help. He also suggests attaching a bar of soap to the trunk - even rubbing it up and down the trunk of the tree before attaching it. Soap scum deters deer.

"The last thing deer want to do is go around smelling like us," Daeger says.

If you stake young trees, limit the practice to about one year. Never stake a tree too tightly; it needs to be able to sway. When a tree sways the cells in the trunk elongate and get used to being flexible. That helps the tree withstand windy days later.

To avoid a scraping wound, use a loose strapping material, such as an old belt, to attach the tree to the stake

If you plant something in June this year, wait until fall of next year to take off the stake, Daeger says.

The Stanley M. Rowe Arboretum, 4600 Muchmore Road, Indian Hill, is open daily, dawn to dusk. (513) 561-5151.

E-mail: GardenStories@cinci.rr.com