Assessing the Health of Trees, Preventing Lyme Disease and Attracting Butterflies

In the height of our growing season, your questions abound.

Q: Your recent column regarding the lingering effects of the drought brought the following questions to mind: If a large tree leafs out only slightly, on a branch or two, is it a goner? What if it doesn't leaf out at all? I've lost several large oaks. Is it best to leave them standing for wildlife habitats or have them removed to prevent borers or other pests? -- Ted C.

A: Healthy plants should be in leaf now, having ample soil moisture, great temperatures and plenty of sunshine. Monitor the progress of your trees. The droughts over the past six years might have damaged mature trees. You could consult with an arborist, but nature will take its course. Regardless of the cause, if a tree is not leafing out by June, or if there is a paucity of leaves (not enough for shade), it's dead or dying. If temperatures hold in the '80s, we should have good soil moisture. Soak trees once or twice during a dry week.

Leaving a dead tree for wildlife is an interesting idea. Owls, hawks, snakes, songbirds and insects could use it. But you didn't indicate the size of your trees or how close they are to buildings, cars and pedestrians. Those should be your major considerations, since trees can fall. Make sure people and structures are out of harm's way, then decide which trees can remain. Open some holes and niches to give the wildlife a head start.

Besides providing food and shelter for wildlife, decaying trees make great trellises for training vines. You can also cut limbs into sculpture, statues or totems.

In your recent column on ticks, you described them as being as small as the period at the end of a sentence. I was not thinking about ticks when I blithely walked through tall grass in sandals to get to my canoe. I noticed two tiny black spots on my foot. I am curious about one's ability to remove (or even correctly identify) something as small as a period. Is it possible? -- Bernice B.

Perhaps I should have said a tick could be the size of a comma. You need to know what to look for. The dot might be moving. It has black legs and a reddish body. However, the larvae and young nymphs can easily fit through the eye of a sewing needle. This is why noticing the bull's eye rash within 30 days after being bitten is such an important indicator of whether you have contracted Lyme disease.

I have a 15-year-old non-bearing pear tree about 30 feet high. Last year it began showing wilted dark-brown leaves. This year it is covered with many wilted dark-brown leaves. What is the problem? What can I do to correct it? -- Dave B.

Flowering pears ( Pyrus calleryana) are showing symptoms this year of fire blight, an enemy of pear and apple growers. This disease, which is caused by bacteria, is most easily spread during the flowering stage. Rain and pollinators spread it. Flowers die, and young growth curls and blackens in areas where the blossoms were. It's most evident in a warm (65 to 85 degrees), wet spring. It could stay in the flowers or spread to kill the tree. You must decide how much ornamental value the tree holds for you. See if the problem persists. If so, remove for a lower-maintenance flowering tree.

Here's how to treat it. (Because of the size of your tree, you may want to hire a tree company.)

Prune and destroy all damaged branch tips 12 inches into the healthy growth. After every cut, disinfect pruners by wiping with bleach and lubricating them with light oil occasionally. (Bleach is quite corrosive.) Next spring, when a quarter-inch of green shows, spray the tree with copper sulfate to protect flower buds. Apply a bactericide/fungicide containing streptomycin when about a quarter of the blossoms open. (I feel the less unnecessary streptomycin is used in the environment, the better.) Repeat every five days while the tree is blooming. Spray again 14 days after the petals fall to control twig blight.

We are landscaping a hill that has been infested with ground bees and ants. We have selected spreading junipers to plant there. We would like to get them planted before summer. We found very aggressive ants when clearing weeds. The bees have left for the season. Previously we treated for ants with boric acid powder. The ants finally left. Can you help with this problem?