Why Do Fruit Split Before Harvesting?

Q. What causes cantaloupe melons to split before they slip the vine?

Melons splitting as they are ripening

A. Like any fruit, when the melon nears maturity and the outside rind hardens and irrigation water is “pumped” into fruit, they split. This can happen with melons, cherries, peaches, tomatoes, cucumbers, and other botanical fruits. Fruit with a thin skin like cherries are more susceptible to splitting after a rain than thicker “skinned” melons. Fruit splitting can happen soon after an irrigation when the temperatures have created a lot of stress or right after a rain.

Peach splitting on the tree

Rainwater enters the fruit through the “skin” or rind and causes it to swell and burst. It is due to an “osmotic effect” and susceptible fruits will split when nearly ripe and their sugar content is peaking. Nearing maturity is the time these fruits are full of sugar and primed for rainfall and the “osmotic effect”. “Nearly ripe” is a dangerous time for a combination of fruit and rain.

Orange split

What to do? First of all, note the variety. Some varieties are more susceptible to splitting while others are not. Secondly, harvest climacteric fruit (those fruit that continue to ripen after they are picked) early. before a rain and let them ripen protected after harvest. Unfortunately, melons are non-climacteric and do not ripen further after picking. Protect the fruit from rainwater and apply a surface mulch during hot weather.

Cupping or Rolling of Plant Leaves During the Heat

Q. Why are the leaves of my fruit trees cupping or rolling?

Leaf roll or cupping on pepper plant even though its mulched

A. Fruit tree leaves of apples, pears, pistachios, tomatoes, and other plants in full sun all day long will sometimes cause the leaves of some varieties to cup or role. Excessive irrigation and fertilizer, high temperatures, the variety of the tree or plant, overly dry soils, root damage and planting shock are some of the environmental factors that can cause physiological leaf roll in fruit trees. Over time all the leaves on the plant may be affected.

Tomato leaf (probably 'Early Girl' cupping or rolling

If your plant is showing lots of leaf roll first blame the high temperatures of summer. Leaf rolling won’t hurt the leaves as long as they remain soft and pliable. Next, be careful of irrigations. Irrigations should keep the soil consistently moist for most garden plants and not allow the soil to dry out rapidly. Apply a surface mulch to slow water loss from the soil and reduce plant stress. Woodchips, straw, shredded newspaper applied a few inches deep will slow water loss from the soil, reduce fruit cracking due to irrigation and conserve moisture.

Leaf roll of mockorange landscape shrub (Raphiolepis spp.)

Retract Your Statement About Poisoning Ground Squirrels!

Q. I am wildlife biologist and a gardener. You should retract your statement about poisoning ground squirrels as the poisoned bodies will appear in the food chain of hawks, owls, coyotes, foxes, and snakes.

Ground squirrel taking the nut from almonds by chewing the outer hull and shell

A. You are right. Poisoned carcasses of any animal can enter the food chain of other animals. It is important to make sure that individuals are following all federal, state, or local laws or ordinances pertaining to the use of a pesticide (whether it is used to kill weeds, insects, protect plants from diseases or terminate the life of a critter) and that any pesticide is used as a last resort. Make sure to read the pesticide label and follow its directions.

After ground squirrels are finished harvesting the nuts, they leave behind the hull and husk which can drop to the ground

            Ground squirrels can rob a tree of almonds overnight. One method to avoid this from happening is to harvest the nuts earlier in the calendar year and dry them in a protected location.

There are different ways to eliminate ground squirrels. Pest control companies exist that focus on “humane methods” and market these options for concerned gardeners. I would refer anyone interested to follow the advice given by the University of California regarding controlling ground squirrels (http://ipm.ucanr.edu/PMG/PESTNOTES/pn7438.html). Please remember that trapping and releasing an animal to another area is illegal in most states and potentially cruel. Check with your local laws.

Nuisance wildlife in Nevada

Bottletree New Growth Dying in Phoenix

Q. The new growth on my bottletree I bought in 2018 is dying (crusty), starting a month or so ago. After talking to the local nursery, I increased the watering and soaked it for about an hour and it now looks worse. I’m watering 6 days a week and each time the tree is getting 22 gallons.

Branch in bottletree dying back.

A. Not sure why you thought the tree looked worse after you watered it. This trees roots are sensitive to watering often and keeping the soil wet. It’s a “deserty” kind of tree, but not truly “deserty”. As a young tree, it needs about 20 – 30 gallons each time it is watered. You are watering the right amount, but the soil shouldn’t be continuously wet six days a week. That’s a mistake. Read what someone else says about this tree in the Phoenix area.

Roots Must Breathe

The roots need a chance to “breathe” after the tree is watered. Knowledgeable people from the Phoenix area suggest watering this tree only twice a month during the summer. Remember, Phoenix is a bit wetter than we are because of their summer monsoons and they get more cloud cover.

My advice is not as dramatic, but I think not giving the soil a chance to dry out between irrigations is a mistake with this tree. Starting this October, try watering less often, maybe twice a week. Apply water to the soil starting 12 to 18 inches from the trunk. This water should wet the soil all the way to the ends of its branches (canopy). This tree likes to have other smaller “deserty” plants getting water near it. Other plants help cool things down.

Apply Water Less Often but Deeper

Apply enough water so the soil is wet to a depth of about 24 inches. This takes somewhere between one and 2 inches of water so that will take about an hour or so. Then hold off on your next water application until the top four or five inches of soil starts to dry out. Then water again. This might result in watering once, twice or three times a week depending on the time of year. Watering fills the soil again with water and then wait long enough for the tree use it. The upper surface of the soil will begin to dry. This drying of the soil encourages deeper rooting of the tree and helps avoid root diseases due to frequent watering. That’s normal.

Inexpensive soil moisture sensor you can buy at any box store

...

            Use an inexpensive soil moisture sensor (like the kind sold for houseplants) and gently push it to into the soil about 4 to 5 inches deep, soon after an irrigation and in several other spots. When the soil moisture averages about “5” on its meter, water again and fill up the soil.

Bottletrees and Leaf Drop

Are Bottletrees Really Desert Trees?

Problems with Bottletrees Growing in the Desert

Bottle Trees Dropping Leaves Probably Water Related

Rosborough and Womack Blackberries Can Be Grown in the Mojave Desert

Q. I am growing Bababerries. What small berries do you recommend for our Mojave Desert climate?

'Rosborough' and 'Womack' blackberries grown at the University Orchard in North Las Vegas.

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A. Growing berries is tough in our desert climate due to summer heat primarily. Bababerry (a heat tolerant raspberry) is a good choice to try due to its heat tolerance. I have not grown it but others claim it works. 

I have had luck growing two blackberry varieties for several years: ‘Rosborough’ and ‘Womack’. I was led to this decision by a publication out of Tucson, Az, regarding some research done in Yuma. I also tried 'Brison' but did not have the luck growing it as I did the other two. Both are “thorny” and grow erect so they don’t need much trellising. Both varieties were released from Texas A and M University in 1977 with very similar traits.

Other varieties (particularly varieties released from the University of Arkansas with native American names) have not been very successful here. All that information is anecdotal as I have not tried them. 

In our climate these berries mature during the heat in May and, like figs, must be picked the same day they are ripe. So mark your calendar for picking when growing these berries. They do not keep well after they are harvested.

You can buy starts of either of these or both by mail order here.

Value of Manure in Landscapes is Not Just for Fertilizer

Q. What is the range of N-P-K value in cow manure that I see some landscapers use for grass?

Manure can be a valuable source of many different plant nutrients, good and bad microorganisms, 

and organics. It is best composted first but in a pinch you can use it raw. Just be careful.

A. The fertilizer content (N-P-K value) of steer or cow manure varies because of what they eat and how the manure is collected and processed. It is considered “low” in fertilizer content as far as fertilizers go. It would take a very small amount of bagged fertilizer to equal the fertilizer content in a ton of manure. Both manures contain about 4% nitrogen and lesser amounts of phosphorus (P value) and potassium (K value). They can both be high in salts and rich in both good and bad microorganisms.

Difference Between Cow and Steer Manure

There is a difference between steer and cow manure. Cow manure is typically derived from cows used for dairy farming. Steer manure is derived from cows fed for meat production. Steer manure typically contains more salt than cow manure and it is considered “hotter” when applying it to plants.

Value of Manure

The value in manure is due more to its potential for soil enrichment rather than its N-P-K content.  For that reason, it can be mixed into a “hot” compost pile. The heat from these compost piles will help to change the microorganism content and decrease or possibly eliminate those microorganisms which are a potential human health problem. 

Research has shown that applications of composted manure can reduce lawn diseases due to its high microorganism count. Application of dry manure is done best with a barrel-type compost spreader.

Winter Pruning of Pomegranate Helps Remaining Stems to Remain Erect

Q. Why do my pomegranate trees have large branches lying on the ground?

Young pomegranates sucker from the base every year when they are young. These suckers need to be removed in winter pruning so that 5 to 6 larger stems remain. This winter pruning and sucker removal helps build the future fruit supporting structure of the pomegranate tree.

A.  I dont have a picture of these limbs on the ground but just went through this at an orchard where I am consulting. The pomegranates were three to four years old and had not been pruned for one or two seasons due to a poorly undiagnosed disease problem (probably crown rot due to frequent irrigations and lots of wood chip mulch applied near the base). This disease problem was spread between plants through pruning. When they were finally pruned this past spring, some of the larger stems laid on the ground. 

Pomegranate dieback disease (probably crown rot due to mulch keeping the stems wet and spread on hand pruners at pruning time), Yes, you can water pomegranate too often.

This happened for a couple of reasons. First, there was ALOT of new sucker growth from the base that caused some crowding because they were young. Sucker growth slows done considerably after about 8 to 10 years of growth and an established canopy. Secondly, they were growing like gangbusters with most of that disease gone. They are flowering and fruiting heavily causing a lot of weight on the ends of these stems.

This pomegranate was not pruned every winter and got out of hand. By this age, the tree should have hand its architecture established so the fruit does not lie on the ground.

This can happen to pomegranates when they have been in the ground for a short time and not pruned regularly. Pomegranates should have emerging suckers removed from so that only five or six of the larger stems remain. Then side growth is pruned from these main stems to about knee height to help prevent fruit born on thick woody stems from lying on the ground. This results in larger fruit produced on the older and thick 5 to 6 stems remaining and fruit produced on these smaller, side, lower branches will not lie on the ground.

This pomegranate has been pruned so that five or six larger stems remain. All the smaller suckers were removed. These remaining larger stems will bare the weight of a full load of fruit in the future. The next step is to remove the side branches to knee height.

The remaining stems will begin flowering and bend toward the ground as the heavy fruit bends them over. As these stems get older, they will get stronger. New growth comes from the remaining bent stems and not as sucker growth from the base. Removing the sucker growth from the bottom encourages the remaining stems to grow strong and erect without crowding them. Removal of sucker growth must be done frequently when they are young until the new growth emerges from the larger stems and not as suckers at the base. You are nearly done. Remove side growth from any of these major stems to about knee height so the fruit produced by these branches do not lie on the ground.

Melon Splitting after a Rain

Q. What causes cantaloupe melons to split before they slip the vine?

Melons splitting can be from several things but usually applying a surface mulch on the ground to slow evaporation from the soil will help

A. Like any fruit, when the melon nears maturity and the outside rind hardens and irrigation water is “pumped” into fruit, they split. This can happen with melons, cherries, peaches, tomatoes, cucumbers, and other botanical fruits. Fruit with a thin skin like cherries are more susceptible to splitting after a rain than thicker “skinned” melons. Fruit splitting can happen soon after an irrigation when the temperatures have created a lot of stress or right after a rain.

Peach fruit split

Rainwater enters the fruit through the “skin” or rind and causes it to swell and burst. It is due to an “osmotic effect” and susceptible fruits will split when nearly ripe and their sugar content is peaking. Nearing maturity is the time these fruits are full of sugar and primed for rainfall and the “osmotic effect”. “Nearly ripe” is a dangerous time for a combination of fruit and rain.

Tomato fruit split

What to do? First of all, note the variety. Some varieties are more susceptible to splitting while others are not. Secondly, harvest climacteric fruit (those fruit that continue to ripen after they are picked) early. before a rain and let them ripen protected after harvest. Unfortunately, melons are non-climacteric and do not ripen further after picking. Protect the fruit from rainwater and apply a surface mulch during hot weather.

Leaf Rolling (Cupping) of Fruit Trees, Ornamentals and Vegetables

Q. Why are the leaves of my fruit trees cupping?

Leaf roll of tomato ('Early Girl' variety, I think) during summer heat but the leaves look fine otherwise

A. Fruit tree leaves of apples, pears, pistachios, tomatoes, and other plants in full sun all day long will sometimes cause the leaves of some varieties to cup or role. Excessive irrigation and fertilizer, high temperatures, the variety of the tree or plant, overly dry soils, root damage and planting shock are some of the environmental factors that can cause physiological leaf roll in fruit trees. Over time all the leaves on the plant may be affected.

Leaf roll of mockorange (Raphiolepis) during the heat of summer (in northern climates the common name of mockorange is a different plant, Philadelphus). Had me confused for awhile.

If your plant is showing lots of leaf roll during the summer first blame the high temperatures of summer. Leaf rolling won’t hurt the leaves as long as they remain soft and pliable. Next, be careful of irrigations. Irrigations should keep the soil consistently moist for most garden plants and not allow the soil to dry out rapidly, a balance between watering too often and not watering often enough. Apply a surface mulch to slow water loss from the soil and reduce plant stress. Woodchips, straw, shredded newspaper applied a few inches deep will slow water loss from the soil, reduce fruit cracking and leaf roll due to irrigation and conserve moisture. Sometimes its just damn hot!

Ground Squirrel Damage vs. Poisoning the Food Chain

Q. I am wildlife biologist and a gardener. You should retract your statement about poisoning ground squirrels as the poisoned bodies will appear in the food chain of hawks, owls, coyotes, foxes, and snakes.

Ground squirrel harvesting of nuts from almonds

A. You are right. Poisoned carcasses of any animal can enter the food chain of other animals. It is important to make sure that individuals are following all federal, state, or local laws or ordinances pertaining to the use of a pesticide (whether it is used to kill weeds, insects, protect plants from diseases or terminate the life of a critter) and that any pesticide is used as a last resort. Make sure to read the pesticide label and follow its directions.

Ground squirrel looking for handouts at Hoover Dam

            Ground squirrels can rob a tree of almonds overnight. One method to avoid this from happening is to harvest the nuts earlier in the calendar year and dry them in a protected location.

Harvested table grapes by a ground squirrel. I challenged him/her/it and saw it jump from the grape vine about 2 pm in the afternoon

There are different ways to eliminate ground squirrels. Pest control companies exist that focus on “humane methods” and market these options for concerned gardeners. I would refer anyone interested to follow the advice given by the University of California regarding controlling ground squirrels (http://ipm.ucanr.edu/PMG/PESTNOTES/pn7438.html). Please remember that trapping and releasing an animal to another area is illegal in most states and potentially cruel.

Do You Want Dark Green Sago Palm (Cycad)?

Let me talk about sago palm (cycad; Cycas revoluta) and growing them in the desert or in desert landscapes. We should be aware that they are NOT palms, they grow best with some relief from the late and midday sun (best on the east side of a home), they prefer to grow in soils high in organics and kept fairly wet. 

Cycads are not palm trees

Canary Island Date Palm growing in artificial grass. They will handle temps below 20F and above 110F but they like some afternoon relief from intense sunlight.

A reader didnt want me to call them sago palms because he thought people might get them mixed up with other palms, like our true palms. He is right. They are far removed from true palm trees. So lets look at a few of the palm trees that do grow in the Mojave Desert and their scientific names. Scientific names (genus, species and even variety or cultivar) say something about their appearance, how they flower or other physical descriptions. If you step back one further in classification, to their Family, it is even more general in nature. Where the sago palm and other palms diverge from other palms is in their Family name; a category of classification more inclusive than their scientific name. 

Palm Family

Palms, as we know them, are in the true palm family, Aracaceae. Sago Palm is not in the true palm family but in its own Family; Cycadaceae. Is it a palm? Technically it is. But it could be called a false Palm, not a true Palm. A more familiar Family to us is Rosaceae or the true rose family. This family not only includes true roses of all kinds but most of our temperate fruit trees (peach, apricot, plum, apple, pear, strawberry) as well as many landscape plants (rose, pyracantha, flowering plum, photinia, and cotoneaster). So compare the true palm Family to the true rose Family. In fact, sago palm is so far removed from palms it is closer to a pine tree than a palm tree!

Common name                        Scientific name                        Family

Mexican Fan Palm                   Washingtonia robusta                Arecaceae

California Fan Palm                 Washingtonia filifera                 Arecaceae

Mexican Blue Palm                  Brahea armata                          Arecaceae

Date Palm                                 Phoenix dactylifera                   Arecaceae

Canary Island Date Palm          Phoenix canariensis                 Arecaceae

Sago Palm (Cycad)                   Cycas revoluta                          Cycadaceae

This is a girl plant. Sagos are dioecious, boy and girls are separate from each other like mulberries and date palms. This is a dainty girl plant. You can tell by the round flower like thing in the center. The boy plants have flowers that look like a penis.

Sago Palm is not a Desert Plant

That's true. It is not but it can handle some of the low humidity, high temperatures and intense sunlight if it is in good health. If your sago palm is surrounded by rock chances are it will not handle the south or west sides of a hot landscape. But if it is in good health, it might. They will prefer growing on the east sides of buildings getting some relief from the afternoon sun or in light to medium shade of a tree.

Sago palm prefers growing in soil with lots of organics in it and then covered with wood chips. They will not grow well surrounded by rock, in rock landscapes or hot sides of buildings (south or west sides).

Plant them in Compost and Cover the Soil with Wood Chips

Will they grow in soils not amended with compost? For a time, yes. Will they grow in landscapes surrounded by rock? Yes, for awhile. But that is not where they prefer to grow. They prefer rich moist soils. To get them in good health to handle the heat then plant them in soils with compost in it and water them like a peach or apple tree.

These sago palms (okay, cycads) are planted on the north side of a home and the soil covered with wood chips.

If you want a sago with healthy dark green leaves that are vibrant and healthy then plant on the east or north side, use compost in the soil mix at planting and cover the soil with wood chips. Oh and dont forget to use about four drip emitters when they are a few years old and water them at the same time as your fruit trees, roses, and most landscape trees and shrubs.

Ash and Plum Success Stories

 

Fan-Tex ash tree about 17 years old. Front yard.

At least 17 years old.  When I got to take care of it 10 years ago, it was on its last legs.  Plenty of bone meal and water. It has great drainage.  I did apply some 30 year old insecticide for ash borers on the trunk about 5 years ago and probably some of that systemic rose fertilizer. The only ash tree in the neighborhood.

Santa Rosa plum tree in the back yard. Notice that the water is applied through drip emitters that apply water to the soil surrounding the tree and covering at least half the area. Also notice that the soil is covered in wood chips that decompose and enrich the soil with organics as they rot near the water.

Planting Peach Tree in the Summer Not Ideal but......

 Q. Here is the hole where I will plant the peach tree.  Still have to add some more top soil/compost mix.  Plan on shading the tree with 40% sun fabric for the first year.  Will mulch heavily but 8 inches away from the trunk.

Planting hole was dug super big and the soil from it was mixed with compost.

A. Planting in the middle of summer when it is hot in the desert is not the best time and not really recommended but it can be done. How?

Not recommending for this time of year but it can be done. Here is how.

1. Predig the hole at least three times wider than a five gallon container. Mix the soil from the hole with a rich compost like you can get from Viragrow, about 25% in the summer (one shovel full to three shovel full of soil from the hole).  Fill the hole with water before you get the tree.

2. While you are out and about getting the compost, get a garbage bag or two full of wood chips from the University Orchard in North Las Vegas. Call 702-257-5555 for directions and availability. You need enough to cover the area around the tree, about six feet in diameter, with wood chips.

3. Pick out a tree in a five gallon container that is healthy with low branches. Small is good as long as it is vigorous. Also buy a role of green nursery tape. When you get home, water it and put it on the north side of the home until early tomorrow. Do you have rabbits? Then pick up some chicken wire.

4. When it is first thing and cool out, remove the plastic container, fluff out the roots quickly, and put it in the hole. It should be the same depth in its new home as it was in the container. Slowly fill the hole with water and  put the amended soil around the fluffed out roots. You should see air bubbles escaping from the planting hole.

5. After seeing no more water on top of the soil, stake the tree so the roots dont move. Cut the green nursery stake free from the tree and pound it in the soil right next to the plant until its solid in the ground beneath the hole. Re-tie the plant back to the nursery stake. Apply wood chips three or four inches deep around the tree but keep it 6 to 12 inches away from the tree trunk.  If you have rabbits in the area, protect the tree with a two foot tall cylinder made from 1 inch diameter chicken wire. If rabbits chew on the tree, it is a goner. Rabbits love to chew on fruit trees. In and is there a the culture and I thinking I just Russians I you and so I'm thinking you'll find in your area will you as you are serious a serious and you will is maybe is a good time love you the possibility is very about the you because I think it would be a mistake to buy anything is very Las Vegas is is expensive but I keep it open is maybe you are a places that can be pretty easy to talk more about the money find this in a you will

6. Do not fertilize if you used rich compost like the kind you get from Viragrow. Water it with a hose the next day and then every other day until you see new growth. Once you see new growth and it is hot outside, water three times a week.

Crape Myrtle Can Be Grown in Desert Soils

Q. I planted this crepe myrtle the first of May. I recently noticed leaf curling and now the brown edges. I’m watering with 6 “ inline tube emitters every other day for 20 min. It’s located in a very hot spot in a corner with south and west facing walls. Any advice would be appreciated.

Crape myrtle newly planted and growing in a raised bed.

A. The browning along the leaf edges either means though tree is not getting enough water or it is being watered too often. The crêpe myrtle will not like hot locations. It doesn’t like hot locations unless you are a very good gardener and can manage that heat and water it needs.

I certainly wouldn’t water more often than every other day. I worry a little bit about two things; is the soil staying too wet between irrigations and secondly is the water getting deep enough when you are watering. 20 minutes of watering doesn’t tell me much. I drink 16 ounces of coffee in 1 ½ minutes. I like coffee when it’s hot. Some other people they can sip on this coffee for one hour. So, 20 minutes doesn’t mean much to me. A crêpe myrtle that size needs about 10 gallons of water. It can get it in 20 minutes or one hour. It doesn’t matter.

Crape myrtle watered with a basin and bubbler, fertilized once a year and using EDDHA iron chelate as its iron source, No organics added to the soil.

I noticed you have what looks like vinca or periwinkle planted with the crêpe myrtle. That is a no no. Vinca or periwinkle has roots that are shallow growing to about six or 8 inches deep. It likes to get frequent watering. The tree on the other hand has roots that are as deep as 18 inches. It likes to get water less often than the vinca but more applied each time. Unless you are a very good gardener and can manage the water between the two the mixing of these two plants together can cause problems in watering. I suspect that’s what you’re seeing. Other deeper rooted flowering plants like rosemary would be a better choice since it has deeper roots and a more similar watering regime.

What to do? 

I am not sure how much water that laser tubing is delivering in 20 minutes. The water for the tree should be applied so that it penetrates the soil each time to a depth of about 18 inches. Then the idea is to hold off on watering again until the soil begins drying in the top few inches. That might be one day or it might be two days I’m not sure. An inexpensive soil moisture meter like for house plants would tell you that. 

Inexpensive soil moisture meter used for monitoring irrigations. Push it in three or four inches in several different locations.

Push it into the soil in three or four locations about three or 4 inches deep and don’t water again until it reads Midway or about five on the 10 point scale. The periwinkle are vinca will drive your watering cycle since they are more shallow rooted.

The other problem you’re going to have with crêpe myrtle during the summer months is its location. As you pointed out it’s very hot in that spot. The crêpe myrtle will improve and looks in October and November but it will not like it there during the heat. The most successful locations for crêpe myrtle in Las Vegas has been on the east or north sides of homes where it’s a bit cooler.

Why Branch Fell off of Mesquite Tree

 Q. This large branch suddenly fell off our 22 yr. old Mesquite tree. We have no idea why. Any thoughts?

When a stem becomes a branch, there is just a thin cylinder that is living inside this branch. The rest is dead wood.

A. When stems are first growing and just young small suckers the entire inside is living and pumping water up and down to the leaves and roots. If this upright sucker is getting plenty of water and lots of light, the growth of this sucker will be fast. As this young stem becomes older and larger, the inside of it dies and becomes dead wood. But inside every large branch there is a cylinder of life protected by the bark that is alive. Instead of having small suckers, stems, that move the water up and down these larger branches don’t need that much living parts of the stem and so this internal "vascular tissue" dies and becomes the internal but dead wood. This internal wood strengthens the branches and keeps them attached to the tree. 

Branches are dead on the inside. This cylinder of living wood inside the branch is "rolling over" the dead wood inside and will eventually fully transport water back and forth between leaves and roots.

Internal Wood is Dead but Strong

This internal wood, since it is dead, can very easily decompose if infected. The outer bark of a tree protects the wood from rotting but if it is damaged by improper pruning or a knife or other accident, then this dead wood on the inside can become infected and die.

 Your Mesquite Branches

The internal wood of this stem on your Mesquite tree has rotted. The stem has weakened because the internal dead wood has rotted or is rotting. This is why I encourage people to sanitize the saw, lopper or pruner before cutting into the bark. Sanitizing sharp pruning instruments helps to protect the internal wood from getting infected, rotting and weakening the limbs. Dead or dying limbs are blown off the tree more easily than strong healthy limbs.

 

This mesquite tree is infected with slime flux or wetwood disease which is common on mesquite. This bacterium will rot the interior of the branch and weaken it.

If you look closely at the internal damage of this branch, most likely you will see where the bark has been injured and disease rotting organisms have gained a foothold inside the branch.

Three Reasons for Spots in a Lawn (Uhm, four)

Q. My hybrid Bermuda grass lawn from seed is coming along well but have this spot that is turning yellow.   Any thoughts?

Spots developing on a seeded hybrid bermudagrass lawn.

A. Do you have a female dog? The brown spots on the bottom of the picture look like dog spots from peeing. Brown spots from dog pee are usually greener at the edges of the spot and then get die in the center of spots that are about 8 to 10 inches across. But there is browning in the center of the picture as well.

Urine damage from dog

Checking for Insect Damage

Yellowing in spots can result from several possibilities. The possibilities are insects, watering or disease. Let’s eliminate one at a time and discover the most likely reason. The easiest to determine our insect problems. On the edge of the yellow area where there is a mixture of green grass and yellow grass pull on the grass like you are playing and pulling at someone’s hair and jerking their head back. Not rough but gently pulling. Most insect problems cause mechanical damage to the plant. When you pull on the grass and it has damage from insects, the grass comes up easily and to severed from the roots. You will get a mixture of green grass that looks fresh and dead grass in your hand. The insects that cause this damage are white grubs usually in the spring and side webworm in the summer. If this is the case and you find this true, then go to your favorite nursery or garden spot and by an insecticide to kill the grubs or side webworm. 

Not Insects?

Now let’s say the yellow spot is not insects. The next category we have to eliminate is disease. Most diseases when they are present will leave a few brown spots on the leaf blades and stems or dieback on leaves or spotting. When you are on your hands and knees checking for insect damage, also check the leaf blades in those areas for disease problems such as small brown spots. This is less likely than insect problems but if you think it might be a disease problem then go to your favorite nursery or garden center and by a fungicide for lawn diseases and make the application. Some lawn diseases can be spread from lawn to lawn by mowers.

Not Insects or Diseased?

The third reason can be irrigation, if you just started this lawn it went be too often and keeping the soil too wet most likely. Once the seed has germinated and the lawn is growing you should not be watering more than once a day. With Bermuda grass you might be able to water every other day even when it’s hot. The only way to know is to try and but definitely not more than once a day. Don’t water your grass again until you see any signs of water stress on the grass. 

Footprints when grasses like fescue need water

This is a smoky green color or when you walk across it it’s leaving your footprints in the grass. This tells you it’s time to water again. In the summertime when it’s hot you can’t fool around and wait a day to get the irrigation on. You must water it as soon as you see it when it’s hot. In cooler temperatures in the 80s you can go a day without watering and it won’t affect the lawn but not now.

Canary Island Date Palm with Dying Fronds

Q. Canary Island date Palm with one or two fronds browning and dying. What to do?

Canary Island Date palm with individual frond death

A. Please be aware of that Canary Island date palms can grow to 50 or 60 feet high so they are too large, in the long run, for residential landscapes. These are huge plants. But these palms grow slowly so it will grow slowly. There are several things that could cause the fronds of this palm to die. The most serious is a disease called Fusarium. You can Google the images and look to see if it resembles Fusarium or not. If the palm tree has Fusarium disease it will most likely not recover but it will get worse in time. If you think the palm trees are infected with Fusarium it’s best to remove them before they get larger and more expensive to remove. The other problem with Fusarium is that it contaminates the soil so few trees can be planted exactly in the same hole. It’s best to plant something close to it but not in the hole. Fusarium is caused by wounds to the palm tree oftentimes caused by improper pruning and sanitation of the pruning equipment and then weakening the palm tree by watering it too often.

The most common problem facing people growing Canary Island date palms in the Las Vegas desert are not amending the soil at the time of planting and watering too often. Watering too often keeps the soil wet and weakens the palm. Pruning these palm trees with dirty pruning equipment causes the disease to enter the plant and watering too often or poor drainage makes the plant unhealthy.

What can you do? 

If you are convinced this palm probably has Fusarium disease, then remove it while it is still small and young. Not many trees and shrubs are resistant to Fusarium. It’s a very aggressive and nasty disease. Make sure the soil around the plant drains water, do not watered too often but if you are watering too much then give it too much water rather than too often.

These can be expensive plants. It might be an expensive educational lesson.

Read Up on Ash Decline and Decide What to Do

 Does Ash Decline Exist? 

'Modesto' ash in a lawn and its dieback.

Read up on the tree disease here, here, and here and decide for yourself.

What is known?

In Las Vegas:

The "condition" was reported by landscaper Nanu Tomiyasu to Yours Truly in late 1980's on mature, 30 foot tall mature Modesto ash trees growing in a lawn near Cashman Field. The trees were given supplemental water and fertilizer but removed when they failed to respond. Yours truly took the State Pathologist, Dr. Wally Sheta, to the site where he thought it might be Ash Yellows and a sample was prepared and sent to the University of Florida for confirmation. The report came back negative for Ash Yellows and this "condition" was not pursued after the trees were removed. It has since been seen in Las Vegas on varieties of Modesto, Raywood, Fax-Tex and Rio Grande ash trees.

In Arizona:

This "condition" has been reported in Arizona by Jeff Shalau in 2018 after an investigation begun by Extension plant pathologist Dr. Mary Olsen started in 2009.

This condition has been reported in the Journal of Arboriculture by Bricker and Stutz in 2005 as a tree disease and MLOs are suspected to be the cause.

All trees infected by this condition die a slow death regardless of irrigation and fertilizer applied. 100% mortality. To my knowledge no pesticides were applied.

What is suspected?

The condition is a disease called Ash Decline in Arizona and caused by an MLO, a Mycoplasma like organism.

Because it is an MLO, it is thought to be spread by insects.

Infects ash trees with Arizona ash (Fraxinus velutina) genetics. Shamel ash (F. uhedi) is thought to be resistant. No trees other than those with F. velutina genetics has been infested.

What to do?

My recommendations are:

1. Remove ash trees showing symptoms after the dieback has been confirmed it is due to Ash Decline to prevent the spread of this condition.

2. Stop the planting of ash trees in the Las Vegas valley.

Bob Morris

To Remove or Not Remove Ash Trees with Dead Branches?

Q. I have been following your comments on ash tree decline. You believe those trees should be promptly removed.  Is this to contain the disease?

Does Ash Decline Exist? Something is causing the limbs to die and water and fertilizer dont change anything.

A. This disease is called Ash Tree Decline in Arizona and Ash Dieback in California. In California, ‘Raywood’ ash has been the hardest hit. In Arizona and Nevada ash trees like ‘Modesto’, ‘Raywood’, ‘Fan-Tex’, ‘Rio Grande’ and other ash trees having Arizona ash genetics have shown branch dieback and “failure to thrive” symptoms.

 We suspect it is an MLO and the "disease" is spread by "something" from tree to tree. Insects? Pruners? Cicada feeds on plant roots like this tree, climbs out of the ground onto the trunk and pupates (leaves its "skin" behind, cuts into trees with its ovipositor and lays its eggs. A possible culprit in its spread?

The disease itself is thought to be an MLO (Mycoplasma Like Organism). What we do know is that it’s probably transferred to new trees by insects, just like other MLO’s. So, my recommendation has been to contain the disease by removing potentially infected trees, so they don’t become a source of inoculum to other trees. If suspected trees receive more water and fertilizer but fail to grow, then we should assume it has Ash Decline until we know differently. I have not seen it on any other trees but relatives of Arizona ash.