Nursery Notes: Trees wallow when roots are too deep

Have you ever noticed how some trees in the field will wallow out an area around the stem? By wallow, I mean, the area within 1 to 2 inches of the stem will have no soil. The tree moves around. As the top moves, the stem pushes the soil away.

If you look down into this wallered out area, something is missing.

Roots! The roots are too deep, but are still anchoring the plant.

As the top moves around, with the roots anchored deep, the stem pushes the soil away.

Another indication of roots being too deep is having to stake plants in their 2nd and 3rd year to keep them upright. Struggling roots are slow to establish and anchor well.

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I visited 2 nurseries last week again that I had visited earlier with roots planted too deep. We went to the same blocks. One was redbud in their third season; the other a red maple cultivar planted last fall. We selected a group of 10 plants in a row at random. We measured down to the first primary root or the root flare.

Surprisingly, the depth averaged 5 inches at both nurseries. The depths ranged 2.5 to 6.5 inches at one nursery and 3 to 8 inches at the other. We might easily allow an inch of soil and say they were planted an average of 4 inches too deep.

Both producers had noticed a problem with the growth and had called me a month or so ago to look at them. The redbud were stressed with a lot of Bots canker. A few of the maples were stressed and were showing premature fall color.

I was assisting Dr. Douglas Airhart from Tenn. Tech. Univ. He was using an Air Spade. He will demonstrate what it can do Friday Sept. 30 at 12:15 immediately as soon as the educational program breaks for lunch at the Civic Center during the MTNA trade show.

The air spade is generally used in the landscape to expose the root system by blowing the soil away. Girdling roots and depth issues can be determined. This is all part of the national approach to bring attention to a major cause of plant decline in the landscape.

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Here is some good information about saddleback caterpillars and the treatment of their “stings” by Dr. Karen Vail.

The “stinging” caterpillar has been making its presence known recently.

The saddleback caterpillar, Sibine stimulea, is brown with a brown circle on its back surrounded by green giving the appearance of a brown saddle on a green saddle blanket (http://eppftpserver.ag.utk.edu/profiles/insects/saddleba.jpg).

A robust caterpillar about an inch long, it is the fleshy protuberances on the front and hind ends that bear the venomous or stinging hairs.

Smaller stinging organs can be found in a row along the sides. An itching and burning sensation may be experienced when this caterpillar is contacted; however, some people may have a more severe reaction from the poison released by the spines and may require medical attention.

According to Short et al. 1997 (http://edis.ifas.ufl.edu/IN014)first aid should consist of repeatedly placing and removing “Scotch” tape from the affected area to remove spines. Ice packs followed by a paste of baking soda and water can be applied to the affected area to reduce the stinging sensation. If the victim has a history of hay fever, asthma or allergy, or if allergic reactions develop, contact a physician immediately.

For images and descriptions of other stinging caterpillars, see the fact sheet at http://edis.ifas.ufl.edu/IN014.