Keeping your trees healthy

By Tay­lor Kaser

reporter@newscolorpress.com

Dis­eases from Asia aren’t just a threat to humans, native trees are fight­ing a bat­tle of their own too. Bugs, fungi, and spores all threaten to dec­i­mate the local flora.

While peo­ple have antibi­otics and mod­ern med­i­cine to aid them, trees are basi­cally on their own, with lit­tle defenses. The help that peo­ple do try to give, through using her­bi­cides and pes­ti­cides, can some­times do as much harm as good.

The Ohio Depart­ment of Nat­ural Resources advises pre­ven­tion to be the best defense against flora ail­ments. Plant trees that are com­pat­i­ble with your intended loca­tion. Exotic trees native to the south­ern hemi­sphere will obvi­ously face greater chal­lenges in Ohio. Also, look for trees that are resis­tant to bugs and fungi that are an issue in your area.

Trees that are phys­i­cally vul­ner­a­ble are also a prime tar­get. Trees may come under “stress” when they are unable to col­lect needed nutri­ents or water. Loca­tion of the tree can also have a bear­ing on its health. Main­tain your trees by reg­u­larly water­ing, mulching, and pruning.

More nat­ural meth­ods of main­tain­ing good tree health include the avoid­ance of high nitro­gen fer­til­izer and chem­i­cal pes­ti­cides. These often kill ben­e­fi­cial insects, microbes, and nema­todes. Other organic sug­ges­tions can eas­ily be found online.

The best aid you can extend to your tree is to keep an “eye on it”. Look for clues of ill­ness or infes­ta­tions. Addi­tional infor­ma­tion can be found at your local OSU Exten­sion office or at ohioline.osu.edu.

The ODNR also gives a list of com­mon tree dis­eases with descrip­tions of what to look out for:

Pow­dery mildew: Usu­ally found on crabap­ples, dog­woods, Eng­lish oak, and catal­pas. Leaves appear to have been “sprin­kled with pow­der.” Nor­mally the older leaves are affected first.

Leaf spots: Fun­gal leaf spots can be found on trees all over the state. Dam­age caused by the­ses fungi is min­i­mal, fungi­cides are rarely needed. Two types of fun­gal spots are most preva­lent: tar spots and fro­g­eye spots.

Tar spots, found on maples, Amur, Japan­ese red and sil­ver, begin in spring as yel­low green cir­cles. By mid sum­mer the cir­cles turn dark.

Fro­g­eye spots attack crabap­ples gen­er­ally, spot begin with a tan­nish hue with pur­ple to red bor­ders and then expand and turn grey.

The sug­gested method of halt­ing leaf spot spread is to rake up fallen leaves and remove them from the vicin­ity. The spots move from fruit­ing bod­ies on fallen leaves.

Insects

Chew­ing insects: Trees can usu­ally recover from the chew­ing assaults of spring and fall canker­worms, tent cater­pillers, gypsy moths, leafmin­ers, and Japan­ese bee­tles. Recur­ring infes­ta­tions could even­tu­ally kill the tree.

Bor­ing insects: These insects carve tun­nels inside of trees where they lay eggs, which some­times after hatch­ing will bur­row even deeper into the tree’s water-conducting tis­sue. When this occurs upper parts of the tree may be starved of essen­tial nutrients.

Small enter/exit holes can be seen in the tree bark accom­pa­nied by small bits of saw­dust at the base or branch bases. Bugs that bur­row are the Asian long­horn bee­tle, bronze birch borer, dog­wood borer, two-lined chest­nut borer, ash borer, and elm bark beetle.

Suck­ing insects: Scales, aphids, leafhoop­ers, spi­der mites, and thrips suck liq­uids from branches and twigs. These insects can be seen on the out­side of the trees, usu­ally in dark scaly for­ma­tions. They often excrete a sticky liq­uids that later turns black and is cov­ered by fungi.

Tay­lor Kaser is a reporter for the Mor­row County Sen­tinel, 46 S. Main St., Mt. Gilead. She can be reached at (419) 946‑3010.

Posted by Rob Treynor on Nov 1 2012. You can follow any responses to this entry through the RSS Feed. Both comments and pings are currently closed.