Palm Fronds Falling From Mexican Fan Palm. Wrong!

Q. I see palm trees with the fronds falling off all around our Sun City McDonald Ranch as on our daily walks. Was wondering if this is part of the palm’s life cycle or is it a disease problem?

Palm fronds falling were thought to be from the Mexican fan palm. Not really.

A. Some palms have fronds that drop from the tree and other palms that don’t. The usual dropping of fronds may or may not be typical to some palm trees like the Mexican fan palm. It depends.

Mexican fan palms flowering.

            It's a genetic issue. Seed production in palms is from the wind, not from bees or flies. There can be a lot of genetic variability when starting plants from seed. In other words, there is a lot of variation in palms because they are started from seed. There is such a thing as "seeded varieties" (some lawn grasses) but for the most part not in palms.  

Mostly California fan palms near a lagoon in 29 Palms.

            The palms you have a picture of are generally Mexican fan palms. Mexican fan palms are typically started from seed. Mexican fan palms are famous (mistakenly) for "self-skinning". There is a lot of variability in that feature of Mexican fan palms. What you are seeing is genetic variability in these palms because of the seeds.

            Palm fronds separate from the trunk because of rotting (rotting diseases) but this does not happen as often with California fan palms. These typically have a fatter trunk that holds on to the palm fronds and may form a "skirt" of old dead fronds that cling to the trunk. So, we call fan palms with a fatter trunk "California fan palm" and those with a skinny trunk Mexican fan palm.

Is the Western Fence Lizard Vegetarian or Omnivorous?

Q. Will the Western fence lizards that took up residence in our yard 2 or 3 years ago and ate our tomatoes. Or has it been something else?  They really keep ants down. Thoughts?

Western fence lizard and meal. From https://www.ocregister.com/2010/06/19/lizards-in-your-yard-are-a-good-thing/

A. My understanding is that the Western fence lizard is mostly a meat eater (ants, roaches, spiders) and not a vegetarian (your tomatoes), but I could be wrong. I thought it would be damage easy to recognize such as rats or rabbits (omnivorous and gnawing damage, my first thought) or birds like the boat-tailed grackle (vegetarian and pecking damage).

Gnawing on tomato not from the Western fence lizard.

            Sometimes fruit like tomatoes will ripen ahead of time if they are damaged first. I would rely on the fact tomatoes are climacteric fruit (they will ripen off of the vine and kept at room temperature for a few days) and avoid the problem and harvest them while they are still green but starting to ripen. The fruit turns from a darker green to a lighter green as part of the ripening process. If this is an "animal" problem, they are sensing ripening fruit and either smell this or see it.

Bird damage on grapes

            This may not be an "animal" problem at all. It might be best to stay ahead of the problem instead of trying to figure it out.

Calcium Deficiency of Tomato and Blossom End Rot

Q. I wanted to ask about a strange occurrence in my tomato garden. Not all, but some of my tomatoes when they ripen, have these black spots only at the bottom of the tomato crop. I just wanted to reach out and see if you could tell me about what causes or could be causing the discoloration?

Blossom end rot of tomato

Blossom end rot of pepper

A. That is normally a physiological problem on tomatoes, peppers and some eggplant this time of year called blossom end rot. Some scientists claim it is caused by an imbalance of calcium in some of the fruit when soils are cooler. Sometimes calcium sprays can fix it. Some varieties of tomatoes show this problem more than others. This imbalance of calcium in other plants is called "bitter pit" in susceptible apples like 'Mutsu' and "corky spot" in susceptible pears like 'Comice'.

Bitter pit of 'Pink Lady' apple

Corky spot of  'Comice' pear

            Apples and pears take regular leaf sprays of calcium as a temporary fix in them. The easiest way to fix this problem in tomatoes is to use a less susceptible variety to blossom end rot. Otherwise, it may take several sprays of a liquid calcium spray (such as calcium chloride or calcium sulfate mixed in water) to fix it. The fruit is okay to eat, it just looks odd.

Sucker Control Under a Wall

Q. My neighbor's tree is sending out suckers that go under my cinder block wall and come out in my planter. I try to pull them out and spray them with weed killer, but to no avail. Is there anything I can do to keep them from coming up? I have the same problem in the front yard but it's the neighbor's palm trees and seeds. They root in the front yard. Anything I can do to kill them too?

Palm seedlings

A. Actually, these are two separate problems. The palm seedling cure is the easiest to fix. When palm seedlings are about 8 to 12 inches tall, pull them out. It works best in wet soil after irrigation. Palm seedlings will die if the bud in the top of the plant, the terminal bud, is removed or killed but it leaves the rest of the plant which can be unsightly. There are sprays that will kill the plant. They are sold as woody brush killers, but they must be sprayed only on the problem areas.

            The first problem requires more work on your part. There is no spray, but you will have to remove the planter, remove or cut the roots that are suckering, and put in a physical “root barrier” and then put everything back.

White Fuzzy Problem Solved

Q. What are those “white fuzzies” on the stems of tomato, peppers, beans, and even outdoor landscape plants?

White fuzzies (as I call them) are egg masses from insects closely resembling tiny cicadas.

A.  These are “plant or leaf hopper” egg masses. Thanks to everyone who responded. Planthoppers and leaf hoppers are basically the same insect. The female lays her eggs on the surface and then covers them with a whitish waxy fuzz. You never see immatures because they drop to the ground from the eggs, much like cicadas. You only see weak winged adults like the grape leafhopper. 

Unconfirmed Eutypa dieback (Pierces disease) on table grapes.

The only times they cause plant problems are when there are lots of them (grape leafhoppers) or when they send viruses and bacteria such as those that cause Pierce’s Disease.

            When these immature forms hatch from these eggs, they even look like very tiny cicadas. If you did see the immature forms from without the help of a magnifier, you might mistake them for flies. Once in the soil, they feed on plant roots until they are adults and need to reproduce. In the case of Eutypa dieback, these insects transmit this disease by feeding on the roots.

Size of Trees and Root to Shoot Ratios

Q. I have a large old 40-foot oleander tree. Every year as it begins to flower, some of the leaves turn yellow and drop. I realize I may need to fertilize but I was also thinking of cutting the trunks at about 20 feet, just below where it branches to encourage new healthier growth. Do you think this is an option? Obviously, I would do it late summer when flowering has finished.

Not a 40 foot oleander as the readers says but this oleander tree is about 18 feet tall.

A. It’s a temporary fix. There is such a thing as “root to shoot ratio”. What that means is that the top of the tree returns to its pre-pruning height as quickly as possible. It’s because of the size of the roots. The energy for growth is funneled into the top of the tree because the roots are at a maximum size for its height. Once the tree “catches up” to the size of its roots, it will slow in its growth because its nutrients for growth are partitioned once again.

Persimmon pruning and root to shoot ratio. This persimmon did not flower or fruit for two seasons until top growth (shoots) caught up with the root size (roots) demonstrating the importance of root to shoot ratios.

            Your oleander needs more water as the summer approaches; four times more from winter to summer and even more as it gets bigger. You can add more water without increasing the minutes by adding or changing drip emitters. But the nice thing about most oleanders is that they handle desert heat well, unlike some other “trees” that get bigger. Oleanders are Mediterranean trees in their water use, not “desert” trees.

December and January plant water use is about 400% more in the summer of June, July, and August.

We have found that giving a tree, growing in a moat six feet in diameter, about two inches of water gives it enough water until its next irrigation. The difference in water use of plants from winter to summer is about 4 times. The number of times that is done in a week or month depends on the time of year and whether it is a “desert tree” or not. At that size, if enough water is applied (so that its roots are wet to a depth of about 24 inches) will last until the next irrigation.

This is about a 15 year old nondesert tree watered with a bubbler and basin (about 15 minutes using pressurized irrigation) at about half of its canopy size. That same tree would require about 7 or 8 drip emitters and watering perhaps two hours to achieve the same thing and using the same amount of water.

What I can’t tell you is how many minutes that takes with drip irrigation. That needs a “gallons to minutes” conversion. In Las Vegas, mesic (nondesert) trees are watered about three times a week in the summer. In the winter they are watered a week or ten days apart, or about four times as long as during the summer months. When changing the irrigation time, focus more on the number of days per week or month rather than the minutes of applied water. It is too confusing. The number of minutes to water is seldom changed with a seasonal change in watering.

Ash Decline (Disease). Or is it?

Q. What might be happening to our ash trees? We noticed that a couple of our ash trees are not doing well at all.  I did a quick google search yesterday and found an article you wrote about ash dieback. I’m hoping that’s not what is happening to our trees, but it does look like it. The only other thing that might have happened is that my husband put sterilant down on some rocks nearby last November. Now we are wondering if perhaps the sterilant made its way down to tree roots that may have been growing beneath the rocks?  I believe he treated the whole area with the sterilant, and you can see where the tree trunk is located in relation to the rocks.  If it is in fact a chemical injury to the trees, is there anything that can be done?

Ash Decline (disease) or not?  Ash Decline looks just like the trees are not getting enough water. You wont know until you water it (give it some extra water) for a few weeks and find out. Unless you want to pay a big plant pathology bill.

A. I don’t think your ash tree has this particular disease. After looking at the pictures you sent, I think it was caused by the sterilant. It’s helpful if you can tell me the name of the sterilant used. Many sterilants are taken up by plant roots. The sterilant damage usually occurs on leaves and stems. On leaves, sometimes they “scorch” (their leaf margins will burn). This is what I think I see. In many cases the leaves turn yellow or become “bleached”.

This is the type of "yellowing" I'm talking about. It is not "sterilant" yellowing but this is the color I am talking about.

            Tree roots watered by rainfall extend horizontally to about the length of their height. So, if you roughly (visually) lay the tree on its side and spin a circle with it, that roughly extends the length of their roots (with rainfall).

Some pine trees I was given to spray with Dicamba, because we saw some dicamba issues on some pine trees when I worked for Utah State University as a Horticulturist.

            In the desert tree roots follow water. Wherever water is applied, that's where you will find its roots if this area is under its canopy. I noticed a lawn under the tree. Did you kill a part of the lawn with sterilant? Many sterilants are taken up by plant roots but this sterilant can oftentimes be seen in the leaves.

Dicamba was also used as a sterilant. This is what dicamba damage looks like on pine trees. Shout out to my friends in SLC Utah.

            If it is sterilant damage, you can try a couple of things. First try to wash it out. It may or may not work. Putting a lot of extra water in that area may flush the sterilant out. Just remember to give a day or so without water to give a chance for the roots to "breathe". Roots need both air and water to survive.

            There is a chance that putting activated charcoal (expensive, activated carbon its called and is specific to the sterilant) may help but it depends on the sterilant used.

            When there is consistent rainfall, roots of trees extend all through the soil under its so-called “canopy”. Your ash tree grows in a lawn. Watering lawns is more even, regular, and consistent than rainfall. Ash trees do remarkably well in lawns. In my opinion that is their preferred way of getting water to the roots.

            Ash trees infected with ash decline are not getting enough water to the dying limbs.  This disease plugs the water conducting vessels in tree limbs. As this disease slowly gets worse, more and more limbs begin dying because of a lack of water. The homeowner ends up removing the tree because it looks “ugly”.

             To see if your tree has this disease or not, give it some extra water once a week during the summer! An extra irrigation during the week tells you if the tree has this disease or not. If the tree does not improve in a few weeks with this extra irrigation, then assume the tree has the disease.

            The mistake made by most homeowners, in my opinion, is not removing the tree as soon as they decide one way or another. If you have confirmed this disease, then remove the tree as soon as possible. This tree can spread this disease to other ash trees!

Roots of Plants Vary in Depth

Q. How deep are plant roots?

Plant roots vary in depth from less than 12 inches to more than three feet. Large trees are watered to the deepest roots get water (guessing its three feet).  Citation is lost.

A. It depends on the size of the plant. This is because the roots of plants extend beyond their drip line. Roots of plants have the potential of growing anywhere under a plants canopy. When a plant is surrounded by dry soil, applied irrigation is very important for root growth. So is air. Roots must “breathe”. If you visually lay a plant on its side spin a circle with it, that will roughly describe where its roots can grow when there is plenty of rain. That is not true in the desert. Even tall lawn grasses have shorter roots if they are watered and then mowed closer to the soil.

Plants generally follow a "40-30-20-10" rule when their roots pull water from the soil. This means as the top quarter begins drying out, the water is used or pulled from deeper in the soil. That is why is it so important not to water every day unless they are very small plants like lawns, vegetable beds and annual flowers. Those roots at the bottom of medium to larger plants cant get the water and their roots suffocate or "drown". Citation lost.

            The functions of roots are not just to supply the top of the plant with water, but this plant must stay upright and resist the pushing by wind. This is one reason why tall plants have water that’s applied deeper than shorter plants.

            If the plant is small, water it only to 12 inches. Small plants don’t need as much support and the water travels smaller distances. Large trees and shrubs are watered as deep as 24 to 36 inches! Their roots must carry water a lot further as well as keep these big plants upright under their weight and in the wind. The water they need is applied to the soil deeper than when watering short plants. They need deep watering because the soil under the roots is dry. Deep roots are needed as the tree gets bigger because of its ever-increasing canopy size and weight.

            The taller the plant the deeper are the plant’s roots needed for transporting water and support.

            As plants get larger, they need an increasing number of the same drip emitters to apply water to the soil. By adding more drip emitters, you can keep the minutes the same. With very large trees and shrubs at some point you may need to increase the size of the emitters, as well as their numbers, to keep the minutes the same.

Stake Wires Will Strangle a Tree If Left Too Long

Q. I have a tree that was staked and now the wires used in staking it are starting to strangle the tree trunk.

Staking trees are for a number of reasons. Make sure the stakes are removed after one year, two at the most.

A. That's a common problem on large, staked trees planted in home landscapes. It's a gamble on the wind whether to stake or not to stake. I encourage people to stake nearly all plants. It's cheap insurance. On smaller 5-gallon plants (sometimes even 15-gallon shrubs) the small, square, green nursery stake found in the container may be adequate if cut loose from the plant, driven or pushed into the moist, solid ground beneath the plant. Retie the plant when you’re finished. Always have some half-inch, stretchable green nursery tape on hand. It's very useful.

If trees are smaller when planting there is no reason to use big stakes. The purpose of staking is primarily to keep the roots from moving until the tree gets established and its roots can keep it from blowing over in the wind.

The purpose of staking any plant is to keep new roots from being damaged during establishment. The movement of roots usually happens during strong winds. Planting in wet planting holes and amending the backfilled desert soil may get around the use of stakes with smaller plants. Use your judgement.

Typically staking is only needed for one growing season and then removed. One growing season is all that is needed to establish plant roots in the surrounding soil and make the plant secure against wind.

Some homeowners may think the reason for staking is to hold the tree upright. That's only partially true. On occasion more than one growing season of staking may be needed when planting trees grown too close to each other in wholesale or production nurseries. In cases like these, metal ties are loosened and then retightened at the end of each growing season to prevent “choking the trunk” as seen in your picture. Remember, plants grow in two dimensions; length AND girth. Sometimes excessively tall and weak plants must be pruned smaller to encourage new, stronger growth.

Staking is sometimes needed particularly to protect the plant from blowing over and stabilizing the roots.

The proper way to stake a tree is to allow the canopy and trunk of the tree to move but not its roots. Movement of a tree’s trunk allows it to gain taper (become stronger) as it grows in size. Trunk taper may or may not be missing because of production nursery practices. Properly grown trees have a tapered trunk as you look at it from top to bottom.

Cracks in Tomatoes

Q. What causes cracks in the tomatoes near the top where the stem is? I have also seen some of my tomatoes with very deep cracks. Let me know what you can tell me about this.

The types of cracks speaks volumes. Longitudinal cracks, like this one running the length of the fruit, is caused by expansion of the fruit when it is ripening. Cracking that are radial, or run around the fruit is mostly genetic.

A. There are two types of cracking, longitudinal cracks (which you have) and radial cracking (which you don’t have). Yours are longitudinal cracks. Radial cracking is mostly a varietal issue. Some varieties of tomatoes show these radial cracks more than others. If you have radial cracks, grow a different variety next season. That will lessen, but not eliminate, radial cracking.

This is a so-called "Heirloom" variety called 'Caspian Pink'. It demonstrates radial cracks typical of the variety 'Caspian Pink'. Not much you can do about it except lessen it under better conditions but the radial cracks will still be there. All type of cracks do not harm the fresh eating of these fruits unless it spoils.

            Another possibility is uneven amounts of water to the fruit. These types of skin cracking causes mostly longitudinal cracks. The swelling of the fruit and then shrinking back to its original size can cause cracking because of the expanding fruit. This type of cracking (longitudinal cracks again mostly) is lessened by using a surface mulch on top of the soil. Sometimes watering differently will help. 

Longitudinal cracking of the fruit by irregular watering even with a surface mulch of straw applied.

If you are using surface mulch, I would recommend wood or pine shavings (like rabbit, horse, or hamster bedding). It “melts” (decomposes) into the soil easier than straw which has fibers that are tough to decompose. Straw works but is more difficult to get it to break down quickly.

            You don’t need a thick layer of surface mulch but just enough to shade the ground and lessen water lost by soil surface evaporation.