Your Garden: The beautiful but competitive flowering pear

Dear Roger: I saw an article in The Fayetteville Observer a week or so ago in which you said diseased pear trees should be cut down.

Were you referring to Bradford pears or what?

I have two in my yard that have cedar-quince rust this year. My agricultural agent looked at them and took a sample and sent it to Raleigh and reported that the rust is coming from a cedar tree near one of the pears.

I plan to have the cedar tree cut down this fall but would like you to tell me if he is wrong and I really need to cut down the pear trees.

I hate to lose any of my trees but will do what's needed. - Ann in Elizabethtown

Dear Ann: You are fortunate to have such an excellent adviser. He is absolutely correct.

I was talking about flowering pears, not the ones you eat. They are commonly known as the cultivar 'Bradford,' though many other cultivars exist.

This tree is so sneaky it can go by several aliases, including 'Chanticleer,' 'Aristocrat,' 'Cleveland Select' and 'Monument.'

The cultivar 'Bradford' has no thorns, but its seedling often do.

Another common name is callery pear, short for the botanical name, Pyrus calleryana.

This tree is a beautiful but vicious competitor from China. It drives out our native plants and the wildlife that depend on them.

A single wild tree can spread quickly by seed and often forms dense thickets within several years. The young trees out-compete native plants.

In forested settings, they leaf out earlier than our native trees, effectively shading out spring wildflowers.

You should cut your trees down, if you love wildflowers and other native plants, birds and other wildlife.

Chances are, their seedlings already have begun to drive out our native dogwoods, redbuds and other choice trees from woodlands near your house.

I would not cut down your cedar tree in any case. Though it is a host for cedar-quince rust, a close relative of cedar-apple rust, other cedar trees are likely to be nearby. The spores from any trees within half a mile or so can infect your pears, not to mention apple trees.

The University of Missouri, department of conservation, suggests the following control measures for callery pears:

"In areas with light infestation, small trees can be removed by hand when the soil is moist, with care taken to remove the entire root.

"When too numerous, foliar spraying with a 2 to 5 percent systemic herbicide solution of glyphosate or triclopyr can be used in mid- to late summer.

"Medium to large trees should be cut down and stumps treated immediately with herbicide to prevent re-sprouting. Effective herbicides include glyphosate and triclopyr at a 25 to 50 percent solution.

"Less labor intensive control options include basal bark treatment and girdling. Basal bark treatment can be used for trees up to 6 inches in diameter by applying a 1:5 ratio of the ester formulation of triclopyr and basal oil in a 12-inch wide band around the entire circumference of the tree base.

"The most successful period for herbicide uptake through basal bark is late winter/early spring or during the summer. Mature trees can be girdled during the spring and summer, by cutting through the bark around the entire trunk, 6 inches above the ground.

"Due to the persistent seed bank and potential for re-sprouting, subsequent treatments will be required for several years."

In your case, you may simply cut the trees down and treat the stumps.

I include full information on control to help others who may have a more serious infestation. And because these pear trees have so many problems, besides splitting limbs and blowing over.

Many people will ignore this, because who wants to get rid of our most beautiful white-flowering spring tree?

My answer: Who would want to get rid of our wildflowers, dogwoods and robins? How would you like to take a walk in the woods and find only wild pears under the big trees? No wild azaleas, no baby dogwoods or redbuds, no wild blueberries, no nesting places for rabbits or birds? And how would you like to be snagged by vicious thorns every step or two?

Cedar-quince rust requires apple or pear trees as well as cedar trees (actually Juniperus virginiana) to prosper. Removing either will help wipe out the rust disease. I'd rather remove the invaders from China than the native cedar.

To control the disease on your cedar tree, simply prune out infected stems before they have a chance to make spores.

Send your questions to roger@mercergarden.com or call Roger at 424-4756.