Aggressive trimming of palm fronds can be harmful

     By Bob Morris
     View columnist
      The following are issues 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.
     
      Question: I was told that my palms need pruning this time of year. They have brown leaves drooping from the top. As long as I am pruning them, should I also skin them as well?
      Answer: First of all palms, if you do elect to prune, should be pruned early in the season if at all possible so that the plant has time to recover from leaf (frond) removal.
      It's recommended that the remaining leaves making the canopy of the palm resulting after pruning should be in a half circle.
      Many times too many healthy leaves are removed from the top of a palm leaving a "feather duster" look. This is done so that the next pruning can be delayed as long as possible.
      Excessive frond removal hurts the health and vigor of the tree. Only remove fronds that are either brown or nearly completely brown.
      For convenience to the pruner, the frond is removed from the tree at a point on the "stalk" (really a leaf petiole) that is the narrowest.
      The remaining part of the frond attached to the tree provides some insulation to the tree even though the leftover base of the frond is dead.
      Skinning a palm involves removal of the base of the frond from the trunk by cutting with a heavy-duty, sharp knife. The base of the petiole is removed at the point of attachment to the trunk.
      This results in a trunk that is relatively smooth compared to a trunk with dead petioles attached. It also gives the tree a more formal appearance. With skinning, the protection afforded by attached petioles is now removed and the plant is more subject to damage due to exposure.
      For this reason I would not "skin" a palm tree during the time of year when environmental stresses (cold, heat) are the greatest. A better time for skinning would be the early spring and fall months. You might even consider leaving dead fronds attached to the trunk and not removing the leaves at all.
      This collection of dead leaves left attached to the trunk is called a "skirt." This gives the palm a very "wild" look that might be very attractive in "native" landscape designs.
      Q: Is there anything I should be doing to my fescue lawn just prior to winter? I heard that lawns should be "winterized."
      A: The term "winterizing" a lawn is a marketing gimmick dreamt up by people wanting to sell products and playing on your sense that you should "do" something in the fall since you may "winterize" your home, your plumbing, etc.
      There really is little to do. There are the obvious things, such as regular mowing, cutting back on irrigations and the like. Things like dethatching and aerating, if done at all, should have been done earlier in the fall.
      There is one thing you can do in preparing green lawns for winter: Fescue lawns low in nitrogen will turn brown if temperatures drop below 20 degrees. If you want some "insurance" against winter browning of lawns such as fescue, an application of a fertilizer high in nitrogen would be a good idea. Any fertilizer high in nitrogen will work. If you haven't been applying a quality lawn fertilizer during the year then I would pick one now to use in late November.
      The application should be right around Thanksgiving time or about two weeks prior to real cold weather coming on. If applied too early then the nitrogen can be leached from the soil and not be effective at the time when you need it. If applied too late then the grass might turn brown early and the nitrogen won't be effective at all.
      Q: I had some terrible luck with periwinkle (vinca) this past season. Some of it died, and that which lived turned yellow. I prepared the soil with organic matter like I was told and fertilized at the time of planting.
      A: It sounds like you had several things going on. First of all we have problems with some periwinkle dying back every year. Usually what will happen is one kind of periwinkle or cultivar will be fine and a different periwinkle dies. Usually when that happens all, or nearly all, of one cultivar dies and the other cultivar does just fine-- even though they're both in the same bed.
      This is probably a root disease problem. Certain cultivars are more susceptible to these diseases than others. There are fungicides that you can apply to protect susceptible cultivars, but the easiest thing to do is not to plant that cultivar again. When you stop in the garden center or nursery, tell them the problem you had.
      They should point you in the direction of different cultivars that are resistant to these diseases. You and the nursery should be looking for cultivars that are resistant to diseases such as fusarium and verticillium. These cultivars are designated from the suppliers of bedding plants with the initials V, F or VF following the cultivar name.
      This oftentimes appears on the seed label, but the grower should be aware of it.
      The second problem you had with yellowing is probably due to a lack of nitrogen in the planting bed. This may have been due to the use of uncomposted or poorly composted organic matter in the planting bed. It's easy to tell if this is the case. Nitrogen deficiency causes the oldest leaves (bottom leaves) to yellow first while the newer leaves (near the top) are greener.
      Dissolve a small amount of nitrogen fertilizer in warm water (maybe a teaspoon in a gallon of water). This can be ammonium nitrate or ammonium sulfate. Put this water in a spray bottle and spray the leaves of the yellow plants. If it's a nitrogen deficiency, the plants sprayed will turn green in a few hours in warm weather.
      n MUMS THE WORD -- Ever think Chrysanthemums were only for Mother's Day?
      Wrong.
      Try coming to the Las Vegas Chrysanthemum Show, sponsored by the Las Vegas Chrysanthemum Society, on Nov. 21 from 1 to 6 p.m. and Nov. 22 from 10 a.m. to 4 p.m. at the Circus Circus Hotel.
      You will learn that not all mums are made the same!
     
     Bob Morris is a horticulture specialist with Nevada Cooperative Extension.