Trees - Oak
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  (January) I have a beautiful pin oak tree that's about 13 feet in circumference. I have allowed English ivy to climb up a good portion of the tree. Will this be harmful? Some have said it will kill the tree, while others have told me the tree is large enough that it will not harm it.

  If it is a well-established tree there should be no problem with the ivy. The only downside is that if something should injure the tree, you won't see it. With young trees, I have seen ivy grow to the ends of the branches, and actually compete with the trees leaves for sunlight, but that should not be a concern for your large oak.

  (March) I have a low area in the front of my lawn. Until recently there was a circular gravel-filled plant bed with junipers etc. I have removed the plants and in the process of removing the white rocks. I want to have top soil hauled in to raise its level. My problem is that there is an oak tree off to the side. How much soil can I add to the base of the tree and not damage it? When should I add the soil and how can I prevent it from washing away?

  I wish there were a simple formula for how much soil can be added around a tree, but there isn't. It depends on the type of tree, the type of soil, the slope of the yard and the area to be covered. Since you are removing some cover, a light covering of soil is going to be fine. If you are just adding to a small area on one side of the tree, and not covering a large area, that too should not be a major problem. For an oak tree, I would not recommend adding more than an inch or two of soil in a large area, but pockets of soil or a thicker layer of mulch would be fine. If there is a slope, you may want to add this at the same time you are planting, so you don't lose the soil to erosion during our spring rains.

  (September) The leaves on many of our oak trees have white insects on them. It is covering the backs of some leaves, and actually falling off. It just started within the last two weeks. What should I be spraying with? I don’t want to lose my trees.

  Cottony aphids and mealy bugs are present in our gardens right now, but this late in the season I would not be spraying, if they are primarily on deciduous trees. The key is to rake up and destroy the leaves as they fall this season. It has been extremely hot and dry and the insects are building up. They are not going to damage a large tree. It is almost time for the leaves to begin falling naturally, so spraying to protect the leaves now, would be pointless. If the nuisance factor is at play here -- the sticky sap is also falling on your patio furniture or car windows, try taking a garden hose at full force and spraying the trees in the areas where they are most a problem.

  (November) As you know by now, those of us with oak trees have an over-abundance of acorns this year. What are we to do? I am afraid they will damage my grass and I don't dare put them in the compost, knowing they will sprout.

  Acorns are in abundance this year statewide. I attribute it to our mild growing season the past few seasons, and the abundance of rainfall. The acorns will pose a nuisance in flower beds when they begin to sprout, but weed-eat, or rake them up now. In the lawn area, regular mowing should control them. If you don't have any squirrels stocking up, I bet you could import some from a few neighborhoods-give me a call!

  We have a large oak tree in our yard that doesn’t look great. Recently I noticed a black sap running out of it midway up the trunk. Insects are circling it. Do you have any idea what is wrong, and how I can correct the problem. I would hate to lose this tree.

  The tree is suffering from wetwood or slime flux. While normally not deadly, it does mean the tree is having problems. Wetwood is a build-up of gas within the tree, which ferments and then oozes out any opening on the tree. It can be white and foamy in appearance or clear and dark. The white and frothy type originates in the sapwood. The sap is rich in starches, sugars and proteins, and produce fermentation, resulting in an odor that is attractive to many species of insects. In the wood, the dark sour liquid is nearly colorless, but darkens on exposure to the air. The slime flux contains acids that are toxic to tree tissues and if left on the trunk for any time much of the bark and even the cambium tissue can be killed. You can bore a small hole in the wood directly beneath where the sap is coming out and insert a piece of plastic tubing in it. This can relieve the pressure and allow the wound to heal. Using a strong spray of water to wash off the offending sap can also prevent further injury to the bark. When the sap stops flowing out of the pipe, remove the pipe. Slime flux is not fatal, but it does mean the tree is in stress. The key to a healthy tree is plenty of water. Fertilization next spring can also help.

  I have a large white oak tree that has the most unusual growths on it this spring. They are about the size of a ping pong ball and are white with tan spots. When pulled apart they appear to contain a fiber and many seeds. What are they, and is there any control? Will they hurt my tree?

  Wherever oaks occur, they are attacked by a group of small insects called gall makers. These insects cause deformities known as galls, of various sizes, shapes and colors on leaves, twigs, flowers and buds. Your "growth" is a wool sower gall caused by a wasp. It is considered one of the prettiest galls. The fiber resembles wool, and the seedlike structures inside, actually each contain a gall-making insect. Galls are produced by a powerful plant growth regulator produced by the insect when it attacks your plant. The majority of oak galls do little or no harm to their hosts. And this is one that looks unusual, but shouldn’t hurt the tree.

  I have a pin oak tree that has an unusual growth on the back of the foliage. It is a swollen ridge that completely follows the main vein of the leaf, and begins to branch out onto the leaf. I have seen galls that were on leaves but they have all been round in shape. This looks more serious. What is it and what can I do to control it?

  This is also a gall, called vein pocket gall. It is caused by a tiny insect called a midge. It won’t hurt your tree, and control isn’t possible once they are on the leaves. Rake and destroy the fallen leaves this fall, but it isn’t cause for concern.

  I am having a problem with an oak tree in our back yard in North Little Rock. We have noticed tiny brown spots, approximately the size of a pin head, covering the leaves which have caused some leaves to wither up and turn brown. There are, also, some pin point size black specks on the leaves and some small white insects and possibly small white eggs. Any advice you can offer would be appreciated

  We have had an abundance of diseases and insects feeding on our plants this year. Typically small spots on large tree leaves is nothing to worry about. there is no feasible way of spraying anyway. The only times I get concerned is if this occurs several years in a row, and causes the trees to defoliate early--by early, I mean in late spring through early summer. This can weaken a tree and lead to other problems. If the leaves are intact, ignore it. Rake up the leaves and destroy them this fall.

  I am enclosing a leaf from my neighbors tree. Can you tell me what the white spots are? They are on the trunk of the tree also. What can be done about it?

  This water oak tree is covered in scale, which I suspect is also what is on the trunk. I don’t often see scale insects on large woody trees. This fall rake up and destroy the falling leaves. Then spray the tree with a dormant or horticultural oil, saturating the trunk and as much of the lower portion as you can reach. I don’t think there is much cause for concern, but try to get a handle on it this winter.

  We have an oak tree in our back yard and it has looked sick all summer. The leaves got raised spots on them, began curling and started falling sporadically in mid June. I have enclosed a leaf for you to look at. We love this tree and would like to save it if possible.

  Many oak trees in the state suffered from an attack of oak leaf blister this season. It is a disease that tends to be worse when we have a cool, wet spring. While it does look extremely bad, and can cause some early leaf shed, it will not be life threatening. Be sure to water regularly during dry weather and rake up the leaves as they fall. Unless your tree gets this disease yearly and defoliates early for several years in a row, this should be nothing to worry about.

  Please see if you can identify this tree for me. I’ve enclosed leaves and acorns. It was growing in the hills of Johnson County by Lake Dardanelle. The tree is about twenty feet tall and about ten inches in diameter.

  The tree in question is a sawtooth oak, Quercus acutissima. It is a great landscape tree, with rapid growth rates. It can grow to be 35 -45 feet tall or more at maturity.

  Enclosed are leaves from my willow oak. I have no idea what the cause of damage is on the oaks. If you have time, please look at the leaves and tell me what to do.

  Your willow oak is suffering, like many plants, with powdery mildew. We are having a bumper crop of the fungus on everything from trees to perennials. If it is a large, well-established tree, ignore it. If it is a small tree, and the leaves are covered, you can use a fungicide such as Daconil or Funginex.

  I have a willow oak tree that was transplanted in November 1995. August of 1996 sap came out of the bark, the leaves turned yellow and fell off. It came back out this spring, and has put on a lot of new growth. The sap started coming out again this past growing season, and in one place I could see small white bubbles coming out. I sprayed and wrapped the body of the tree with tape to keep the bugs from sucking the sap. It appears the bark is turning dark and a small crack is appearing farther up the tree where the limbs start. Is there any treatment that will correct the problem or is it a lost cause? I have another tree that was planted in 1991 and I have had no trouble at all.

  Your tree has been suffering from a disease known as wetwood or slime flux. While normally not deadly, it does mean the tree is having problems. It is a build-up of gas within the tree, which ferments and then oozes out any opening on the tree. It can be white and foamy in appearance or clear and dark. The white and frothy type originates in the sapwood. The sap is rich in starches, sugars and proteins, and produce fermentation, resulting in an odor that is attractive to many species of insects. The slime flux contains acids that are toxic to tree tissues and if left on the trunk for any time much of the bark and even the cambium tissue can be killed. You can bore a small hole in the wood directly beneath where the sap is coming out and insert a piece of plastic tubing in it. This can relieve the pressure and allow the wound to heal. Using a strong spray of water to wash off the offending sap can also prevent further injury to the bark. When the sap stops flowing out of the pipe, remove the pipe. I would not recommend wrapping the bark, as this may cause more damage to the outer bark. Slime flux is not fatal, but it does mean the tree is in stress. Fertilize the tree in the spring, and pamper it some the next growing season to get it back into a healthier growth pattern.

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