Possible to Stop Berries Produced by Palms

Q. My palm trees continuously produce berries. I keep cutting them off but they come back. Even the new 1-year-old palms I planted have green berries on them.  Is there any way to keep them off?  Are there palms that do NOT produce berries?

A. Production of these berries or fruits and dropping them on the ground is a natural occurrence every year on all palms. They produce flowers on long stalks, the flowers become fruits or berries and they drop from the tree and litter the ground.

This is a major objection to palms growing near swimming pools. Once a palm is old enough for flowering, it will continue to flower and fruit every year. There is nothing that you can do to prevent the sequence of events leading up to the production of these berries. There are no chemicals you can apply to prevent this from happening.

However, there is one simple thing you can do. When it is ready to begin flowering you will see stems growing from the trunk. When they are long enough, cut off them off with a pruning shears.

Flowers emerging from Canary Island date palm in the spring.

Cutting off these flower stems prevents the production of fruit and will not harm the palm. If the palm is too tall, use a pole pruner to cut them off or a ladder and a loppers.

These flowers will make thousands of "berries" that will drop to the ground. Cut off the flower stalks with a loppers or pole pruner.

If you want it done commercially, coordinate the pruning of your palm at the same time it produces flowers and cut them off at the same time the palm is pruned.

Rings on Peach Fruit May Be Disease, Frost

Q. What is wrong with my peaches? I left you a voicemail. I'm not much of an e mailer. These peaches are 30 miles south of Mesquite. Around 4500 elevation. The spots showed up essentially as the peaches formed. 

A. And I am not much of a phone person. I am working outside of the country right and I did get your voicemail but responding to you is easier for me through email. It allows me to collect my thoughts and gives you a written record of my thoughts and recommendations.

This is not something I have seen before on peach fruit. I have seen something similar to this on apricot. The things that jump out at me are your location south of Mesquite and your 4500 foot elevation. Three things came to mind when I saw the picture; virus disease, early spring frost damage or powdery mildew or similar disease developing on the fruit during cool, wet weather.

You didn’t tell me if you’ve seen it in previous years but if this were a virus disease you would've seen it before. The fact that you did not mention that it leads me to believe this may be a one-shot problem and not one that is reoccurring. This kind of eliminates virus diseases. But your pictures very closely resemble a virus problem.

 Peach Virus Diseases Click Here!

Although it really does not resemble late frost damage too much, because of your elevation, I am thinking it might be a possibility. All it would take is some temperatures slightly below freezing for an hour or even less just as the fruit were forming. Frost damage might cause some fruit drop while damaging others and not affecting others that remain on the tree.

 Frost Damage to Peach when it reaches near maturity

There is a microclimate in the tree fruit canopy that can affect frost damage severity for the entire tree. If this were freeze damage to immature fruit I would suspect it would be more of a problem on the north side of the tree, fruit exposed to windy locations or at the top of the tree rather than lower and inside the canopy.

Diseases like powdery mildew can leave this kind of a mark on immature fruit. It would have occurred during or slightly after rainy or wet weather and on fruit that were protected from wind by leaves or inside the canopy of the tree. Fruit in areas exposed to full sunlight and lots of air movement would, most likely, have fewer problems.

Perhaps powdery mildew on apricot

If this were a virus disease, it could have been brought in with the tree when it was purchased. It is also possible that the tree was infected by neighboring trees with the same virus. The third possibility, if the tree was grown from a pit or seed, the seed could have come from an infected tree. Virus diseases of fruit trees are usually a problem when people do not purchase “clean” nursery stock. Make sure you purchase fruit trees from nurseries that are using and producing plant materials that are certified free from diseases.

Perhaps powdery mildew on apricot

If you grow your own fruit trees from pits or seeds, disease problems like this are always a possibility. It may be rare, but it does happen. If you planted from seed and you think this may be a virus disease, there is not much you can do except live with it or replace the tree.

If you decide to live with it, it is possible the disease could spread to other plant materials in the Orchard or your neighbors.

If you think this may have been a disease problem such as powdery mildew or close relative, make sure your peach trees are not growing close to apple trees which may contribute to the problem.

If you think this is a disease problem that is not a virus, you should prune open the canopy more so that there is better air circulation and light penetration inside the canopy. Secondly, spray with sulfur applications shortly after rainy or very wet weather to help prevent the disease from developing on fruit.

Clark County Code 30.64.030 Restricting Hardscape to 60%

Q. If Clark County Code 30.64.030 restricts hardscape to 60 % which includes paved areas, pavers, rocks, stones, etc where does xeriscape fit into this issue, please?

A. It is my understanding that hardscape does not include mulches (rock mulch used for desert landscaping). These are not permanent features of a landscape such as drives, sidewalks, decking. etc. 

I think the point that concerns the government is that they do not want someone coming in and paving the entire landscape to save water, reduce maintenance, etc. 

Hardscapes increase surface runoff to storm sewer systems and add pressure to waste water treatment facilities and a number of other issues. However, I was not a part of this discussion and really not qualified to address it. Perhaps someone who is closer to the government issues and county codes can address this better than I can.

During Hot Weather Increase How Often You Water, Not How Much

Q. With the temps averaging 110 F, how much and often should I be watering my shrubs and trees?

A. I would normally not increase the number of minutes on an irrigation clock but add one more watering day each week as it gets hotter. I would not recommend changing the number of minutes under normal circumstances but the number of watering days in the week. You seldom change the number of minutes on an irrigation clock after you are satisfied with your landscape irrigations.

The number of minutes on an irrigation clock delivers a set volume of water during a cycle and it does it the same every time it comes on. This set volume of water fills the same volume of soil every time for every plant on that valve or station.

This set volume of water wets the soil to the same soil depth and same spread every time it comes on. It’s like filling a gas tank on a car.

This wetted soil supplies water to plant roots. Each time after an irrigation, that specific volume of water fills the soil to the same depth and width every time. Roots grow into these areas to get the water they need. Plant roots dominate the wetted soil where there is irrigation water. They do not grow into areas where there is little to no water.

As temperatures increase, the amount of water needed by plants also increases and they consume water in the soil more quickly. Relating back to a gas tank of a car, we fill the soil with water again when the “gas tank” is about half empty. This means as temperatures get hotter we must fill the soil with water more often.

This jump from 100F to 110F (10° F change) seems big to us but it is not as big as the jump as the jump from February to June (30 to 40° F). Usually an increase of one day each week, or about 20 to 30%, is enough to handle a 10% increase F in temperature.

The Whiteflies are Coming! The Whiteflies are Coming!

Whiteflies are the proper name for those tiny little, gnat-like, delicate flies that swarm off of plants like tomatoes, eggplants, peppers, grapes when you touch the leaves. They are located on the undersides of the leaves (as most bugs are) and fly off of the leaves when they are disturbed.

They like the heat of the summer. They don't particularly like the cooler spring and fall

Whiteflies, most likely ash whitefly, on pomegranate

months. Whiteflies suck the juices out of plants in much the same way aphids, scale insects and mealybugs do. Because they suck plant juices by tapping into the plant with their mouthparts they poop out sugary excrement that attracts ants.

Yellow sticky traps can be made with bright yellow paper or paint and a sticky surface like vaseline

You can use yellow sticky cards hung in the garden area to trap some of them but if there are loads of them you all have to spray. Try insecticidal soap first and see if you can reduce their numbers with that. If that doesn't work, try pyrethrins sprays to see if you can get some control that way.

Tomato Plants With No Fruit. What's Happening?

Q. We have several tomato plants that had grown well with lots of leaves but there is no fruit production. We have a good soil blend and other greens like kale, red and green chard are doing well. I know that it has to do with pollination or lack of it and wonder what else we can do to help these tomato plants.

Tomato flowers not setting

A. Several factors come into play regarding tomatoes not setting fruit. Let's keep in mind that some varieties of tomatoes are better suited for our hot, dry desert climate than others. Good performing varieties have included Early Girl, Patio, Jet Star, Champion, Roma, Big Boy, Better Boy, Sweet 100, cherry tomatoes in general, grape tomatoes to name just a few. There are others as well. Heirlooms typically struggle in their production so selecting a variety that you know should perform well and then experimenting with others that are unknown is probably a pretty good idea.

Tomato flower on left has set but tomato flower on right did not.

The second problem is regarding how rich the soil is and the fertilizers applied. Extremely rich soils with a high percentage of manures can promote a lot of top growth at the expense of flower production. In other words, amending the soil with a lot of rich ingredients high in nitrogen will promote a lot of leafy top growth early in the season, delaying flowering. 

Be careful when amending garden soils that you don't overdo it with amendments. If you have a productive garden already, I would not add more than 1 inch of compost to the soil and digging it in to a depth of 8 to 10 inches. Soils that are not productive or have never been underproduction might require 2 to 3 inches of compost initially added to it with a 1 inch layer applied in subsequent years.

Starter fertilizers added to the soil at the time of seeding or putting in transplants should be fertilizers high in phosphorus (the second number) with moderate to low amounts of nitrogen (the first number). Once a starter fertilizer has been used, you should not fertilize tomatoes with a high nitrogen fertilizer until you begin to see flowers setting. After flowers have set fruit, then go ahead and feed the plants with small amounts of fertilizer once a month.

The third problem is regarding the air temperature. Once air temperatures climb above 95°F and nighttime temperatures are warm, tomatoes will no longer set fruit. 95°F is not an on and off switch for setting tomato fruit. Some tomato varieties will stop setting fruit in the low 90s and others will stop when temperatures get our bit higher.

Keep your tomatoes healthy during the heat of the summer and if summer temperatures cool off to the low 90s for a brief time they should set if nighttime temperatures are dropping as well. When temperatures climb back up again, they will stop setting again. If you can maintain tomatoes into the early fall, they will start setting fruit again when temperatures drop down.

How to Spray When Mantids Are in the Garden

This question was posted to the Desert Horticulture Yahoo discussion group! Come join our desert horticulture discussions  and ask to be a member.

Mantid egg casing on a tree.

Q. Well they are back and so the battle begins.  I’m just starting to see a stinkbug or 2 and a few leaves on my squash has eggs on them.  I know just how fast those hungry buggers can suck the life out of cukes, squash, melons or whatever sounds good to them. 

This year I bought some praying mantis eggs/nest.  It’s impossible to see when they hatch and leave home so I just thought they died.  Imagine my surprise to now be finding baby mantis’s in my front and back yard....on the very same plants the squash bugs are hitting. 

So here’s my question.  To spray for the bugs or hope the praying mantis’ will feast on the squash bug buffet? 

Thoughts, ideas or opinions?  All are very much appreciated!
-Sue

A. Sue, that’s a really good question and it is one of the major difficulties we face when we try to manage our garden and fruit trees organically or as organically as possible. You have introduced an insect predator into your garden to help keep some of the "bad bugs" under control rather than to use pesticides. It is one of the cornerstones of integrated pest management or IPM. We should also be realistic about what praying mantis can and cannot do. They are not focusing on "bad guys" to help you, they are just looking for a meal. Their meals include "good bugs" and "bad bugs".

This idea works great with some pesticides approved for organic production and it does not work well for others. For instance if we use a pesticide allowed in organic production that targets a certain pest while not harming others it can work fine. An example is using Bt that kills only the larva or worms of moths and butterflies but we want to protect the praying mantis. It is totally safe for the praying mantis since it targets only the worms or larva of moths and butterflies. However, if we are realistic, it also kills the larva of butterflies which are not plant pests for our gardens.

However, if we use insecticidal soap, which is also recommended in organic production, and apply it to our vegetables or fruit trees, we are applying it is an "indiscriminate killer"; it will kill any insect on contact, squash bugs, leaf footed plant bugs, aphids, honeybees as well as praying mantis. 

When we choose to use an "indiscriminate killers" but want to keep beneficials, like praying mantis, from getting harmed, then we must direct the spray on the insects we want to kill and avoid spraying the ones we do not want to harm. This requires a lot of plant inspection on your part; looking for, identifying and targeting the "bad bugs" with the spray. 

Focusing on the use of beneficial insects as your primary method of controlling "bad bugs" limits your ability to use pesticides. You must either not use pesticides or select pesticides which will not harm the beneficial insects or direct any pesticide sprays so that they come in contact only with "bad bugs".

Another approach is to use these indiscriminate killers, such as insecticidal soaps, to keep bad insects under control and realize you will have "collateral damage". The "collateral damage" which occurs is the killing of good bugs and bad bugs with the hope that the good bugs will recover after the spraying is over. 

You also select "organic" pesticides that do as little damage to the general insect population as possible. This type of spray program limits the use of beneficial insects for any long-term control. It is really a "spray and pray" program.

Enjoy your praying mantids. They will migrate to other parts of your landscape as well as your neighbors. Visit and inspect your garden and fruit trees often. Use plants sprays when "bad bugs" are getting out of control and target your sprays on these "bad bugs".