Sapsucker damage not life-threatening to trees
Q: I noticed that woodpeckers attacked our palo verde tree. There are probably 60 holes around the truck and main limbs. The sap is running even though the holes are just under the surface, not deep. Any advice on how to prevent further damage and do you think this can eventually kill the tree?
A: This is probably one of the sapsuckers. Sapsuckers are a type of woodpecker and a couple different types have been documented in Southern Nevada. Some sapsuckers migrate through the valley and others maintain a year-round presence.
They damage a variety of trees including fruit trees and many different types of landscape trees. They frequently come back to the same tree over and over.
The only thing you can realistically do is exclude them from the tree. This means putting up some wire mesh, burlap or other barrier to keep them from the trunk and larger limbs. They will still get into limbs where it is hard to put a barrier.
I have seen the same fruit trees damaged year after year for the past 20 years and the trees still seem to be doing well. Damaged trees repair themselves more quickly if they are in good health — watered and fertilized adequately. I know it causes damage but it doesn’t seem to be life-threatening so I would let it go unless the damage gets extensive.
If this seems to be seasonal, you could try some hot pepper sprays just before they begin damaging plants. Mark the event on your calendar and time your applications accordingly.
Q: My friend has a lantana plant and the leaves look good from the top to about the bottom few inches and then they turn yellow. What might be the cause of this condition? My lantanas are getting very thin and “leggy.” Do you think I should wait until December to cut them to the ground as some say?
A: These plants originate from wetter climates and richer soils. As these plants get older and woodier at the base, they tend to lose their leaves toward the bottom and keep the leaves on the more succulent stems and new growth.
This is worse if the plant is not in full sun or if it is very dense. Regular applications of fertilizer help along with correctly pruning the plant. Prune these plants to within an inch or two of the soil surface in February if they are leggy. They also need plenty of water so if water is being restricted they will also look pretty bad.
Lantana loves full sun and does very well provided the soil has been enriched and it is receiving fertilizer. If planted in rock mulch, the soil will become mineralized or lose its organic matter content over time and the plant then does poorly.
Get lantana on a schedule every couple of months with a decent fertilizer for flowering plants. In the spring, apply compost or composted chicken manure or something similar around the plant and water it in thoroughly with a hose. You want to rebuild some organic matter back in that soil again.
I had several reports of grubs feeding on the roots of these plants. When this happens, the plant begins to decline. It might not be obvious to you unless you dug the plant up and examined the soil.
If you believe this could be a problem, you would apply a granular insecticide or a liquid drench around the outside perimeter of the plant. Granular organic insecticides containing rosemary and thyme oil work as well as conventional insecticides containing imidicloprid.
Q: Last week, I heard about a variety of apple called the Pink Pearl, not Pink Lady. Will Pink Pearl apple trees survive the Las Vegas growing season? Do you know where I can get a sapling?
A: I have heard of Pink Pearl apple but I don’t how it will perform here. Nearly any apple tree will grow in our climate, but it’s really a question of how good the fruit will be. It originated in Humboldt County in Northern California, and it ripens sometime in late August or September. In Las Vegas, it might ripen a couple of weeks earlier than that.
The eating quality of a specific variety of fruit is affected by the climate where it is grown, the soils and how it is managed. Pink Pearl has a good reputation in Northern California but its quality is unknown in our hot desert climate. I would hate to see you wait four or five years only to find out the fruit is not good quality.
I am confident it will set fruit provided it gets pollinated. In its place, I would advise you to select an apple that ripens very early in the summer or in the fall months and avoid apples that ripen during the hot summer months. My experience with apples that ripen in July through August here has not been promising.
Q: I have a rosemary bush in the front yard that’s very healthy but has grown quite big in the seven years since it was planted. Is there a technique to trimming? I tried once before and it looked like a really bad haircut.
A: Any older, woody plant will have its leafy growth on the perimeter of its canopy. If the plant canopy is dense, which is typical of rosemary, all of the leafy growth will be in a 2-inch layer along the outside of its canopy.
Leafy growth needs sunlight. Shade causes leaf drop and prevents leaves from developing. Dense plant canopies don’t allow sunlight to the interior. This means that the woody growth in the interior will be leafless, bare, naked.
If you begin cutting away deeper than 2 inches then you will expose the interior, bare wood. This does look like a bad haircut.
The good thing is that bad haircuts are not permanent. New growth emerges from these bad haircut areas because of sunlight and the stimulation the plant receives when it is pruned.
Shaping plants should begin when they are young. You cannot wait until they are several years old to begin shaping them unless you are willing for that plant to have a bad haircut for awhile.
Pruning rosemary depends on whether you want it as an ornamental or you plan to harvest the rosemary for cooking. If you are harvesting rosemary for cooking you want to harvest soft, succulent growth.
Alternatively, you can harvest the woody growth and strip the leaves off. Commercially, pruning is done with shears because it is faster. Again, if you cut too deeply with shears it will look like a bad haircut.
After pruning always make sure there is enough warm weather for regrowth to occur. Water and fertilize the plant to stimulate new growth and recover from pruning.
If you want your rosemary to be an ornamental, it can adhere to any shape you want to give it. It can be sheared or it can be pruned with a hand pruners.
During this past holiday season, we saw upright rosemary pruned into small Christmas trees available at nurseries and garden centers. Just don’t cut the plant too deeply.
I prefer a more normal look. This is done by reaching deep inside the plant and removing older wood with hand shears. By reaching inside to make cuts, the cuts are hidden by the remaining growth. If you prune like this, it will never look like the plant was pruned, just smaller.
To look for the longest growth, follow the stem back inside the canopy to a place where it joins another branch. Cut and remove the longer stem and leave the shorter one. This would be done in several places each year to keep it restrained.
Bob Morris is a horticulture expert living in Las Vegas and professor emeritus for the University of Nevada. Visit his blog at xtremehorticulture.blogspot.com. Send questions to Extremehort@aol.com.
