Question
I have two large catawba trees in my yard. This is the first year I have owned the property and when they put on leaves the leaves seemed to be much fewer than I had seen on other catawba trees. Now Sept.15 they seem wilted and turning yellow. They have had plenty of water as I have supplimented water that the automatic sprinkeler system gives them. Also some flowers near the tree have yellowing leaves while the same flower farther away look fine. I have applied a tree insect killer with no change in the appearance of the trees. Any help would much appreciated as I really would hate to loose the trees.
Thanks
Bill Shumate

Answer
I would fertilize them. Here is how to do this and the web link where you can see the measurements easiler.
http://www.state.sc.us/forest/refcare.htm#fert

"Fertilization aids in maintaining tree vigor, promoting new growth, and overcoming insect, disease, or wound problems. Small, yellow-green leaves, sparse foliage, or leaves dropping early may be indicators of the need for fertilization. Fertilization is not a "cure-all" for declining trees, but may be used to complement other tree maintenance activities.

The ideal time to fertilize is late winter or early spring just before the leaves begin expanding. Fertilization may continue until mid-July. Avoid fertilization late in the growing season which may stimulate a flush of new growth that would be susceptible to damage by an early frost.

Fertilizer should always be applied to moist soil to improve uptake and to reduce the chance of root injury. If soil is dry, irrigate prior to fertilization.

Application Rate:

A soil test is best for determining the amount of fertilizer to apply, especially in coastal areas where soils may be high in phosphorus. For most areas, the following guidelines based on the distance to the edge of the branches may be used for fertilizing established trees:  Step 1 - Measure the distance from the trunk to the edge of the branch spread; this is the crown radius.


Crown Radius = distance from edge of branch spread to trunk.

STEP 2 - Use the table below to determine the amount of fertilizer to apply. Find the crown radius in the left column, then look in the appropriate column for the type of fertilizer that you are using to determine how many pounds of the fertilizer to apply. An 18-5-11 type fertilizer would have the best ratio of Nitrogen-Phosphorus-Potassium, 16-4-8 is considered good, and 12-6-6 is acceptable.

If the area under the branches is restricted by sidewalks or driveways, or the root system has been damaged by construction, the rate should be reduced by an equal percentage to avoid damage to the tree.

FERTILIZER APPLICATION RATE :
Crown Radius (feet) BEST
Pounds 18-5-11 to apply GOOD
Pounds 16-4-8 to apply ACCEPTABLE
Pounds 12-6-6 to apply
0-5 1 1.5 2
10 5 6 8
15 12 13 18
20 21 24 31
25 33 27 49
30 47 53 71
35 64 72 96
40 84 94 126
45 106 119 156
50 131 147 196
55 158 178 237
60 188 212 283

NOTE: If using a slow release fertilizer, use twice the indicated amount and apply it every two years.
One pound of fertilizer is approximately two cups.


METHOD:

Apply fertilizer to the soil surface, starting 2 to 3 feet from the trunk and extending several feet beyond the furthest branch tip. If the soil is compacted or grass is present, drill holes in the soil to apply the fertilizer.

The drill hole method requires that holes be dug in a 2 foot by 2 foot grid pattern starting 2 to 3 feet from the trunk and extending slightly beyond the edge of the branches. Holes should be 8-12" deep and 1 -2" in diameter, and may be made with a fertilizing auger, pipe, broom handle or tire tool. To avoid damaging the roots, mix fertilizer with an equal amount of peat or other organic material and stay at least 6" from small plants. The total amount of fertilizer should be divided evenly among the holes. The increased amount of air available to the roots is often as beneficial as the fertilizer.

WARNING

Use of lawn fertilizers which contain herbicides for broadleaf weed control will cause tree damage or mortality. Do not use herbicide type fertilizers or soil sterilants in the area beneath the branches of trees."