Fruit tree care - August

August Tree Care 2008

August is the time to check for pear sawfly (cherry slug) damage, ground falls, and dry soil.

If you have cherry trees, you will want to check for pear sawfly larvae damage. Although a pest of all fruit trees, cherry trees seem to be especially susceptible in northern Nevada. Examine the leaves on your cherry tree for leaf damage evidenced by the upper surface of the leaf is gone leaving only the brown skeletal veins. Then look on the leaves for a small (3/8 inch long and 1/8 inch wide), slimy, dark brown to black, little slug—the larva of the pear sawfly (a small wasp).

If the damage is extensive (more than 20 % of the leaves effected) and the larvae are still present, take action. I generally will spray with Sevin. Organic methods include picking them off by hand (yuck) or sprayed off with a water hose. If unchecked, the larvae will strip the leaves on a large portion of the tree and severely damage the tree if not kill it.

I have noticed apples dropping off trees early this year; these are called ground falls. Most of the apples that fall off the trees before they are ripe do so because of codling moth damage or watering problems. Ground falls should be removed and disposed of as soon as possible as they may still contain codling moth larvae or pupae. If the apples have been on the ground more than 24 hours, do not consume them as (harmful) bacteria have likely started to bloom in them. If you have ground falls, clean up under the tree and dispose of the damaged apples. Then, each day, pick up the falls in the morning and evening; when you have enough for a pie, cut out the damaged portions and use.

Check your soil moisture by digging a small hole just beyond the drip line of the tree; the soil should be moist but not soggy. If the soil is hard and dry, increase watering. You will also want to check the moisture in your garden and yard as well.

Now is the time to apply Bt to tomatoes to kill the tomato hornworm before one eats one of your tomato plants for dinner. Buy a small container; it goes a long way. I mix and apply with a sprinkler can.

Michael
8/3/08