Stopping those pesky spider mites

September 27, 2008|By BOB KESSLER

If you grow pine, spruce, fir or hemlock trees, you should be aware of spider mites.

If you have seen yellow needles on your tree that are mottled in appearance, this is probably from spider mites.

To check for spider mites, take a plain sheet of white paper and place it under the branches of your trees and give the branch a sharp tap.

Now look at the debris that fell on the paper. If you see dirt specks that start to move, then you likely have spider mites.

To control spider mites, you should use 3- or 4-percent horticultural oil. You can get horticultural oil at most garden centers.


Spray your trees so you have plenty on the needles, even to the dripping point. Be sure to check the label for more details.

Buy local apples

Now is a great time to visit the many roadside fruit stands in our area and buy local fruit. If you want to keep apples over a longer period of time, you can do this if you have extra refrigerator space.

Sort out any damaged fruit to use right away and place the pieces in good condition in a well ventilated container such as a plastic bag with some holes in it.

Store your apples around 32 to 35 degrees. Do not let your apples freeze.

Do not store with onions, potatoes or herbs, as the apple will pick up the flavor.

Be sure to check the fruit frequently to remove any that are starting to go bad.

With the proper conditions, you can enjoy autumn produce well into the winter.

The woolly bear

Have you seen a woolly bear caterpillar yet this fall? This is the time of year when you can see them as they move in our landscape and search for a place to overwinter.

These are the critters that kids and adults like to pick up and look at and some even use them to predict what the winter is going to be like.

The woolly bear is the caterpillar stage of the tiger moth. There are actually eight distinct woolly bear species in the United States.

You might find two species in this area. The most common is the banded woolly bear, which is black at both ends and reddish brown in the middle.

The woolly bear has been the best-known caterpillar because in 1948 Dr. C.H. Curren of the American Museum of Natural History in New York proposed a scientific study to see if the woolly bear does indeed indicate what our winter will be. The publicity from this study made it famous.

What is known is the black on the caterpillar is affected by the age of the caterpillar and by the moisture levels in the area where it developed. Yet today you will still find people who swear by the woolly bear as a predictor of our winter weather.

Some people are so serious about them that they hold a festival in Vermillion, Ohio. This year's festival will be Sunday, Oct. 5. It is the largest one-day festival in Ohio and includes a huge parade that takes more than two hours. Merchants sell woolly bear T-shirts and hats.

This fall, when you see a woolly bear caterpillar moving through your landscape, stand back and give the caterpillar proper respect as one of the most famous caterpillars we have.

And remember: The amount of black on the ends of the caterpillars do not predict a good or bad winter.

(Yet, interestingly enough, people say the woolly bear is right more than half the time - at least, according to my contacts who watch the woolly bear.)

Grow a mighty oak

If you would like to grow your own oak tree to plant in your yard, you need to collect acorns this fall. It is very important that if you are going to try to grow your own acorns that you do not let them dry out. If you have a tree in your yard, pick up the acorns you are going to plant as soon as they fall. You can test acorns by placing them in a pan or a bucket of water and the ones that sink should be ok to plant. The ones that float are not likely to germinate.

Once you have your good acorns, you can either plant them in a bed in your yard or you can plant them in a container. A third option is if you have the exact location you want for your tree, plant several acorns in that area and then next year thin out to one tree.

In any of these sites you should plant your acorns about two inches deep and plant at least three to four acorns for each tree you want to have.

The type of tree you collect your acorn from will determine what happens next. If your acorns came from an oak tree in the white oak group, they will germinate this fall and start a root system, but the top growth will show up next year. If your oak is in the red oak group, nothing will happen until next spring.

If you are using a container, you should use a good potting mix and you will need to protect the container from drying out this winter. If you can't do that, then place your acorns in a plastic bag in the refrigerator until you can plant next March.

Keep in mind that trying to start in containers is very tricky. You will be more successful by planting in a bed and then moving it to a new location in a year or two.

Bob Kessler specializes in consumer horticulture and energy for Penn State University. He can be reached weekdays at 717-263-9226 or by e-mail at

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