Various factors can result in pine needle droppings

     By Bob Morris
     View columnist
      The following are typical questions our Master Gardeners deal with daily at the Nevada Cooperative Extension. If you have gardening questions, call the Master Gardeners' hot line at 257-5555 between 9 a.m. and 4 p.m. Monday through Friday. There is also a gardening Web site at http://www. intermind.net/mgarden/.
     
      Question: The pine needles are turning brown and dropping on the inside of my pine tree. What can I do?
      Answer: Dropping pine needle can be result from underwatering, overwatering, shock from transplanting, weed killer damage or a natural occurrence. Another possibility is the plant was recently moved or planted from the nursery.
      This is the result of what is called transplant shock. Transplant shock occurs when a plant has been accustomed to growing in a certain way and then is suddenly thrust into a new environment.
      If a plant is grown in a cool environment and then moved to a hot environment, leaf drop can sometimes happen. The same is true if a plant is grown in a humid environment and then put into a dry one or if a plant is taken out of its container and left too long before planting or if it's planted in a dry hole.
      If needle drop is happening on the inside of the tree only, this also could be natural. Needles on a pine tree may represent growth up to 5 years old. The oldest needles will be on the inside, with the new needles on the growing ends.
      Look at the newest needles to determine what is happening to the tree now. If the newest needles look healthy, the plant is probably doing OK. If the newest needles are browning, dropping or dying back, then you have a problem with the tree right now.
      Look for overwatering, underwatering or poor drainage. These are the most common problems associated with needle drop this time of year.
      Q: My lawn has a large brown area that resulted from a plugged sprinkler head. What should I do about it now?
      A: The grass may not be dead. Tall fescue has fairly good recovery from drought. Bermuda grass has even better. Immediately water the area thoroughly. Simply turning on the sprinkler system and running it through a cycle will not be enough.
      Very dry soil will require more water than moist soil to bring it up to the moisture content of the rest of the lawn.
      Put a hose on the area. Cut a small plug of grass from the lawn with a pocket knife. Pull the leaves away from the stem of the plant. On a grass plant, this is the thick part of the plant that supports the leaves. See if the stem is green where the leaves are attached to it.
      Check several different plants from the brown area. If there is green tissue on the stems, the lawn may recover with just water.
      Recovery may take seven to 14 days. If the grass is dead, then reseed this fall or resod the area. Sodding can be done now if you are diligent with your watering. Seeding should be done in September or October.
      Q: I have some black, scabby growth on the branches of my oleander. What is this?
      A: The description is a little different than the way I would describe it but it sounds like your plant has bacterial gall. This is a black growth that appears as a black knot on the branches. It's easy to miss since it's buried by other branches inside the plant canopy.
      You would usually find bacterial gall when you're pruning. It's more of a visual problem than a plant health problem. It can cause the plant to weaken and grow poorly.
      Correcting the problem is easy. Prune out the infected branches all the way to the ground if possible. If it's not possible, prune them out as low on the branch as possible. Spreading the disease is usually through pruning.
      When an infected shrub is pruned, the disease can be transmitted to a healthy plant with the pruning shears. This is a bacterial disease and so, like many bacterial diseases, pruning equipment should be sterilized between each cut.
      Sterilize the shears with alcohol or any bacterial disinfectant. Oil the shears after you finish all the pruning.
      Q: I have flowering plums with borers. What's going on?
      A: Don't jump to conclusions. How do you know your tree has borers? Did you see them or remove the bark and see their damage? Or are you just seeing sap coming from the trunk. There are some trees like Arizona cypress and Hollywood twister juniper that, when we see sap, we are very confident that borers are the problem.
      Stone-type fruit trees (peaches, plums and nectarines) and their relatives, such as the flowering plum and almonds, can have sap coming from the trunk and limbs without having borers. This is very common during the summer heat and is related to heat stress. Sometimes we call this "gummosis."
      Even this term isn't correct, but it at least lets us talk about the problem without mistakenly calling it borers.
      To determine if it is really borers, use a pocket knife and carefully cut the bark where damage is seen. Is there a dark, sawdust material under the bark? Is there an internal cavity where the borer has tunneled? If you see these borer activities, follow borer-prevention advice. Call our Master Gardeners for borer information.
      They have information on natural control methods or they can provide you with advice about traditional pesticide practices.
     
     Bob Morris is a horticulture specialist with Nevada Cooperative Extension.