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Saturday, November 28, 2015

Philippine Government Officials Visit Las Vegas on Agritourism

Release Date: November 30, 2015
Kill Date: December 19, 2015
Contact: Robert Morris, 702.630-5173; 702.610-5035

Las Vegas Visits Impact Philippine Agri-Tourism

Las Vegas – With 32 million credited to the Las Vegas tourism count through September, no one thinks about the agricultural side of the gaming industry. No one thinks of Las Vegas as a place to grow food. They do in the Philippines. Their reasoning: visitors have to eat and the restaurant scene is changing rapidly.
        Three government officials representing the Philippine Department of Agriculture recently took note of changes they predict will impact agri-tourism in the Philippines. Most notable is how government involvement can foster or hinder development of this new industry.
      The restaurant industry has marketed itself differently in Las Vegas during the past decade paralleling consumer demand. These changes are trending internationally as well. Themed restaurants have emerged which embrace the locally grown food trend, eating healthy and growth of farmers markets.
        Philippine government representatives visited several producers of local food in Las Vegas. Here they learned about enticements and barriers producers experienced working with local government agencies to bring locally grown food to area restaurants frequented by tourists.
          In a recently published Restaurant Business Online survey, 15 of the top 100 restaurants in gross food and beverage sales are located in Las Vegas. The number one restaurant grossed $47 million in 2014. Tourists visiting Las Vegas spent over 60% of their tourism dollars on food and drink. This equated to about 70% of their gambling budget.
        The Philippines is poised to become the next most attractive gambling hub in Asia given its proximity to a range of key tourism markets.  It attracts over 4 million visitors each year with a 40% increase in tourism over the past three years and expected to climb dramatically. Dramatic increases are attributed to increased gaming restrictions in Macau, the world’s largest gaming destination, and the shrinking Chinese economy.

Robert Morris is an Emeritus Professor with the University of Nevada, Reno and retired Horticulture Specialist with Nevada Cooperative Extension. He is local and international horticulture consultant who contributes weekly with his own byline to the Las Vegas Review Journal. Visit www.xtremehorticulture.blogspot.com

If you would like more information about this topic or schedule an interview with Bob please call him at (702) 630-5173 or email him at Extremehort@aol.com

Saturday Fruit Tree Pruning Classes in North Las Vegas

I will be giving free fruit tree pruning classes to the public on Saturdays in December.Classes will be held at the UNCE Demonstration Orchard located 100 yards east of the intersection of North Decatur and Horse Road. Horse Road is located 2.8 miles north of the Bruce Woodbury Beltway in North Las Vegas. Bring your pruning shears, loppers and saw if you have them.

Pruning Class Schedule
Saturday, December 5    845 AM to 1 PM
Saturday, December 12  845 AM to 1 PM
Saturday, December 19  845 AM to 1 PM

All three pruning classes will follow the same schedule:
  8:45 AM  Preparing your equipment for pruning
  9 AM       Peaches and Nectarines
10 AM       Apricots, Plums and Their Relatives
11 AM       Apples and Pears
12 PM        Pomegranates, Figs and Persimmons

Please don't be late for the fruit trees of your choice.

Tuesday, November 24, 2015

Leaves Remain on Trees If Weather is not Cold

Q. I have two dwarf peach trees. They are still loaded with leaves. What can I do about it?

A. Nothing. Just let them drop normally. One good night of near freezing or freezing temperatures and they will drop. Prune them in mid to late January.
Normal fall leaf drop on peach

            Another method you can use to drop the leaves is to begin restricting water to the tree. If it’s possible, turn off the drip emitters or bubbler to the tree for a couple of weeks. You will not hurt the tree and you will encourage leaf drop. When the leaves begin to turn yellow resume your irrigations.

Figs Remaining on Tree During Winter is Normal

Q. Our fig tree is losing all of its leaves but still has fruit on it. What can we do?
The third crop of figs in Las Vegas does not have enough time to ripen before freezing weather. The figs remain on the tree after leaf drop, dried and inedible.
A. This time of year figs lose their leaves, it is normal. It is that time of year.
            What confuses you is that there is fruit remaining on the tree and you would like to harvest it. Figs, in our climate, have three crops each growing season but unfortunately our season is not long enough to support the third crop. So this crop is lost to winter weather.
Mixture of early figs (briba, lower. older wood) and main crop (smaller, above, new wood) coming on a little later, less mature.

            The first crop of the season grows on the wood produced last year older wood and is called the briba crop. The second and third crops are called the main crops and develops on new growth.

            What you are seeing is normal. Enjoy the first two crops and remove the third crop and put it in your compost pile to prevent possible future disease or insect problems. However, I must admit, I usually let the immature fruit from the third crop drop to the ground where it rots in the wood mulch beneath the tree with no problems.

Protect Citrus From Freezing Temperatures Soon

Q. When should I begin to protect plants like citrus from the freezing weather that’s coming?

A. Some citrus will handle the cold weather better than others. Most of the citrus sold in this area are grafted to a cold hardy root system called a rootstock. Damage or even death results when the temperatures remain low enough to kill the top of the tree, its root system or both.
This citrus died from winter freezing temperatures several years ago and the sour orange rootstock grew in its place producing oranges that were too sour to eat.

            The more cold hardy and reliable citrus here are kumquat, grapefruit and Myers lemon. However, they will not survive the cold if the roots which they are grafted to are not cold tolerant as well. Most plants sold by nurseries in this area have citrus on cold hardy rootstock. This might not be the case if you buy citrus online.
Spring freezing weather caused this fig to die back and push new growth from lateral buds along the stem.

            None of the citrus are severely damaged if temperatures remain above 32° F. The least cold tolerant of the citrus, such as limes, is damaged when temperatures drop below freezing. When temperatures are low enough to damage the top of the tree but not the rootstock, suckers or water sprouts grow from the rootstock the following spring while the top of the tree may be dead or severely damaged.
Freeze damage to bougainvillea
            As we start getting close to 32F, start watching the local weather reports or track the low temperatures online. When you see projected temperatures reaching 32° F or lower, wrap the base of the tree with a blanket or cover this area with mulch. Smaller trees or trees pruned into an espalier may be entirely covered with a blanket.

            Some people wrap tender trees with Christmas lights on a timer that comes on at night. This may work if temperatures are not extremely low and there is no wind. Blankets should be removed the next day when temperatures climb above freezing.

Soaking Seed in "Fortified" Water Does Make a Difference

Q. I am new to starting my plants from seed. I read an article about soaking seed with fish or seaweed solution before planting. I am trying broccoli seeds which are small and I used water from a fish solution. Am I on the right track?

A. Yes, you are on the right track. Let’s focus on vegetable seed which are fairly easy to germinate. When seeds germinate, they first “soak up” water from its surroundings. This is called imbibition.
            Imbibition causes seed to swell or enlarge and begins all of the internal chemistry which pushes it towards germination. That is, IF the temperature is correct for that seed. By the way, imbibition does not tell you if the seed is alive. Imbibition occurs if seed is alive or dead.
            If a seed imbibes water and begins the process of germination and the seed dries out after this, living seed will die. It had its chance and failed.
            For imbibition to occur, the seed must be in contact with the water long enough for water to be absorbed. This is an important concept in the desert. If the seed comes in contact with water for five or 10 minutes, and then dries, it will not imbibe water. The seed will not germinate but it may still be alive. If this happens too many times in a row, the seed will die.
Large seed like this runner bean seed is easy to soak in water, surface dry and plant. Small seed are difficult.
            Seed must be in contact with water for a fairly long time for imbibition to occur. This is the reason I encourage gardeners who are germinating seed in the garden during the summer months to use a thin surface mulch. This surface mulch reduces evaporation from the soil and leaves soil water in contact with the seed for a longer period of time.
            The water that moves into the seed during imbibition carries with it whatever nutrients are in solution. So if you have dissolved nutrients from sea kelp or a fish solution, that water will enter the seed and provide nourishment to the seedling.
            That was a long winded answer that basically says, “Yes, the quality of the water used for germinating seed may have an impact on the growth of a seedling.” I will caution you though. You do not want a strong solution when imbibing seeds with water. If this water has a high nutrient content from the sea kelp or fish solution, it could kill the seed or damage the seedling. It is best to dilute it.
            Another word of caution. Once you retrieve these small seeds from this solution of water, they will be wet, cling together and be difficult for planting. It is much easier if they are allowed to dry before planting.
            Here is where you have to be careful. If you dry seeds too long before planting you risk the possibility they will die. If you do not wait long enough, they are difficult to plant. Allow seeds to dry on their surfaces, only, before planting. Do not let them dry further than this or you may kill the seed.
When seed first begin to germinate (left) the beginning of the root, the radicle, is the first to emerge.
            And another word of caution. If you wait too long before planting and these seeds begin to germinate, you will see a tiny projection coming from the seed. This is the beginning of a root called the radicle. It is very easy to break this radicle when you are handling the seed as you are planting. If it breaks, the seed is dead.Throw it out.

            Imbibe the seed with cool water for 24 hours. Surface dry the seed long enough so it can be planted easily and immediately plant it in warm soil.

Special Fruit Tree Orders No Longer Available

Q. In the past you took special orders for bare-root fruit trees. I am looking for a fig tree. Will you be repeating the offer this year?  If so, when will the information be posted in your Saturday newspaper article?

A. I am sorry I no longer provide that service to the local community since I left the University. However, nearly any type of fig will grow in this climate and many can be purchased locally or online.
Kadota fig
            The most common figs selected and have a history of doing well here include Kadota in the category of yellow or white figs, Black Mission and Brown Turkey in the category of dark figs. The white or yellow figs have a mild flavor while the dark figs are typically stronger in flavor.
Black Mission fig
            Keep in mind that several of our birds love figs and you will be in competition with them when they are ready for harvest. Figs can only be harvested when they are soft and ready to be eaten. They cannot be picked early, like peaches or apricots, and the fruit allowed to mature off of the tree.
The darker figs generally get larger than the yellow figs
            The nice thing about fig trees is that they can be pruned heavily and still return a good crop the following year. The biggest mistake people make with figs is not giving them enough water or not watering them frequently enough. Water them just like any fruit tree.
            This lack of water results in fruit that does not mature, stays small and hard and is inedible. If this lack of water occurs early in the development of the fruit, it will drop from the tree.

I do understand that the University of Nevada Cooperative Extension is providing fruit trees for the local community. I am not involved in this program so I will not guarantee what is available meets my criteria for local production.I would strongly suggest that you visit the list I published a couple of years ago on this blog. Or send an email to me and I will forward the publication to you.

Be Careful of Fruit Growing Wild in Your Landscape

Q. My husband found a plant growing wild in our garden with green berries in clusters that turn dark blue or black. He tasted a few and they seem to be okay. We looked at pictures on the Internet but it does not resemble any of the common berries. Did you know what this is?

A. I think you have black nightshade. Several people have sent me pictures of this plant growing in their garden. It is a fairly common weed in the garden and landscape that gets mixed up with tomato and pepper seed.
Black nightshade
            This plant can be found worldwide and is extremely variable in leaf size, leaf color and whether the leaves are smooth or hairy on the surface. The berries of this plant are pretty consistent in size and color in a rather distinctive cluster and a good way to identify it.
Fruit and flowers of nightshade

            There are several countries that do eat different plant parts of nightshade and promote it as an herbal medicine, food or for livestock but the American black nightshade is poisonous and should not be eaten in any form.

            Be careful of internet information. This plant, because of its variability, may vary in the amount of poison it contains in different parts of the world. To be on the safe side, consider it a poisonous weed and get rid of it.

Can I Transplant a 10-year-old Palm Tree?

Q. We have a palm tree, perhaps a Mexican fan palm, that was planted close to a wall and I have to move it because the wall is damaged. I'm guessing the palm was planted 10-15 years ago. Can the palm be transplanted or is it a loss?

A. You have two problems with that palm; it is too close to a wall which makes moving it very difficult and it requires a crane if you want it moved. Moving it will be very expensive and it will not be worth, monetarily, transplanting it to a new hole. If you decide to move it anyway then you would move it during the warm spring months or even summer but avoid moving it during fall and winter.

Wall cracking because of roots lifting the wall. This is typically not the case with Palm trees but the trunks of some palm trees can be a problem.

            Palm trees are full of water and fan palms can run from 200 to 500 pounds for every foot of trunk depending on the diameter of the trunk. Palm trees with larger diameter trunks can weigh 1000 pounds or more per foot. This does not include the weight of the root ball.
            Cut your losses and have it removed. Unfortunately palms do not burn very well and are not used for firewood since it produces little heat when burned and burn quickly when dried. The wood does not compost very well either.

Are Any Vegetables or Herbs Available Locally As Transplants?

Q. You mentioned growing winter vegetables such as spinach, cauliflower and others. Are these vegetable plants available locally?

A. We are seeing more and more of these plants available as transplants locally as the trend in vegetable gardening has grown but it is still hit and miss to find them.
            Most of these plants can be planted directly in the garden from seed easily. Certainly the leafy green vegetables should be started from seed and not purchased as transplants. These include spinach, lettuces, mustards, kale and the like.
            There are only a few winter vegetables that should only be started from transplants and include Brussels sprouts, cauliflower and cabbage. Almost all of the other winter vegetables can be started from seed directly in the garden if soil temperatures are warm enough.
            If soil temperatures are not, cover the area with plastic where seed was placed and cover the edges with soil so wind does not pick it up. I have some information I produced on soil temperatures required for different seed germination.

            The advantage of starting vegetables from seed is freedom from some of the pests and diseases found in greenhouses as well as any pesticides that might be used on them. Sometimes you may have to start these vegetables from seed when transplants are not available locally.

If you want some videos on any of this let me know. I'll be happy to make them and post them on YouTube with a link back to my blog.

I have included a copy of a vegetable and herb planting calendar for the winter that I did for a local compost company, Viragrow.

Why Does My Sumac Have Yellowing and Dying Branches?

Q. I have a 20-year-old sumac tree that has developed yellow leaves in several areas. There has been no change in watering or the soil. What is causing this and how can we treat it.
Branches dying in the bottom of the canopy of sumac. This may be due to too much shade. If not, it definitely contributed to the problem.
A. If the yellowing or browning of the leaves is occurring in shaded areas it might be because there is not enough light reaching the leaves. If the canopy is dense and creates too much shade then leaves and stems in these heavily shaded areas will die. When the leaves are first dying they turn yellow and finally brown when they are dead.
            Try removing some limbs on the tree to allow more light to penetrate inside the canopy. The problem is that African sumac responds very well to pruning with new growth and limb removal might have to be done regularly.
Regrowth or watersprouts coming from a large African sumac limb after removal.

            Do not remove too many limbs but allow the entry of filtered light inside the canopy.
            An easy way to see if enough light is entering the canopy is to look at the ground. If the ground beneath the tree is a solid shadow, not enough light is entering the canopy. It should be pixelated. Some limbs should be removed until the light on the ground is “speckled”.
            You can do this pruning any time of the year and do not have to wait for winter. I would focus on removing limbs around 1 inch in diameter and no larger unless the tree needs major pruning work done. Do major pruning only in the winter months.
            African sumac does not have very many diseases so I have ruled out the possibility of disease. At least in our desert climate.. It has a few insect problems but nothing serious except aphids which leaves a sticky or shiny appearance on the leaf surface.

            Aphids would be a problem in the spring and fall months. Heavy feeding by aphids could cause yellowing of leaves as well but they will be sticky. They can usually be removed with soap and water sprays.

When Removing a Lawn, Large Trees Frequently Die

Q. We’re seriously considering getting rid of our turf and taking advantage of the SNWA Rebate Program ("Grass for Cash" Program).  However, not at the expense of our beautiful fruitless mulberry. What steps do we take to maintain the health and vitality of the tree? 
Mulberry that might be threatened in a "cash for grass" rebate program. Most landscapers will not provide enough water in the right locations for a tree of this size to survive.
A. Great looking tree and I applaud your efforts to keep it although I am sure those with severe allergy problems would like to see it gone.
            As you have discovered, the water needed to support a tree like that is nearly equal to the amount of water applied to the lawn underneath it. The best advice I have is to maintain the grass directly under the canopy of the tree. If you decide to remove all the grass, then you will need to add a way to deliver enough water directly underneath the canopy.
            A method that some people are using is to lay a coil of in-line drip emitters around the tree in a spiral, spacing the tubing about 12 to 18 inches apart. Use tubing with emitters spaced about 12 inches apart along its length.
            The less distance between emitters, the less time will be needed for watering. I am guessing this method will require about one hour to deliver enough water for the tree in a single irrigation. Other plants can be planted in this area that will take advantage of the wetted area.
            Another method, and the one I like the most, is to flood irrigate about half the area under the canopy with two bubblers in a constructed basin that is at least one third the diameter of the canopy. The basin must be level so that the water does not accumulate on one side of the basin.  It will take about 10 to 15 minutes to fill the basin with enough water to supply the tree.
Pine tree with a bubbler and basin used to for irrigation. The bubbler releases water quickly and fills the basin. It is important that the bottom of the basin is flat.

            The most common option is to use drip emitters under the tree. This seldom works when keeping large, mature trees like yours healthy. You would need a very large number of drip emitters to deliver enough water. Very few retrofitted desert landscapes use enough to keep the tree from dying back.  
This tree previously was growing in lawn. This area was converted to a rock landscape, the grass removed, to conserve water. This tree was not provided with enough water after this conversion so it began to die.

            Consider covering the soil under the tree with wood chip mulch rather than rock mulch to maintain good “soil health” under the tree. Good soil health was promoted in the past by maintaining your lawn. With the lawn gone and the soil covered with rock mulch, soil health will be severely impacted which will negatively impact the health of the tree in a period of 3 to 5 years.

What Edibles Can I Grow in Shady Spots Along a Walkway?

Q. I am creating garden beds along a walkway on the west side along a north facing wall. It is shady there most of the day. What edible plants can I grow there this time of year?
Here is the walkway in question
A. The area next to the sidewalk is a long, a north facing wall so it does not get much sun. Because it receives less sun, the production of food will be lower. To come close to maximum production of food of good quality it needs at least eight hours of bright light. Very bright indirect sunlight reflected from light colored walls will help production in this area a lot.
            Less than six hours of bright light will severely impact the quantity and quality of vegetables produced from flowers such as tomatoes, peppers, squash, etc. There will be fewer flowers and thus fewer fruits from these flowers.
            You would focus on greens, many kinds of herbs, possibly onion and garlic. Keep in mind that leaf and stem growth is also affected by light. Leaves that grow under lower light levels tend to be larger, thinner and tend to tear or rip more in wind and when harvested. They also tend to be less bitter.
            On the flipside, vegetables produced under the high light intensities of the desert tend to be more compact, thicker, more bitter and frequently tougher in texture. Full sunlight tends to produce more nutrient-dense leaves, stems and fruits but may reduce its eating quality or texture.

            This time of year focus on the cool season stuff like mustards, kale, lettuce, spinach, and beets, cauliflower, broccoli, rapini, carrots, escarole, mizuno, and the like. Some herbs include parsley, sage, rosemary, thyme, chives, lavender and cilantro.

What Cause Whitish Spots on the Leaves of Star Jasmine?

Q. My star jasmine leaves are covered with a whitish plaque. The leaves are turning yellow and falling off. I have noticed the green leaves are only at the end of a branch and bare to the main stem. The plant is approximately two years old and facing east on the side of a patio. What can be done?

Star jasmine with whitish spots on the leaves.
A. I took a look at the picture and I saw the white spots on the leaves but I could not determine what it was from the picture and your description. I can only tell you about some general problems with star jasmine.
            First of all, star jasmine will do very poorly in desert soils if the soil was not amended with compost or a good soil amendment at the time of planting. Their roots will not tolerate soils that drain water poorly as well. They do like soils covered with organic mulch.
            They tend to get root rot diseases in these types of soils and they will develop yellow leaves along with leaf drop just like you are describing.
            However, the white spots are a bit of a mystery. Star jasmine has milky sap in it stems and if the stems are cut they will drip a milky sap on the leaves so watch for that. If they were pruned recently they might have the milky sap dripping on leaves.

            This would probably be unrelated to the yellow leaves and leaf drop you are mentioning. Bottom line, don't plant star jasmine in our desert soils without amending the soil a lot with compost or other suitable soil amendment. Consider organic mulches on the soil surface.

Growing Redwoods in Las Vegas Poses Long-Term Problems

Q. We are growing some redwood trees on our property in containers. Some of them on the south side of the home that have been in containers for several years have branches dying at the bottom. Younger ones in containers on the north side seem to be doing well.

A. Congratulations that you are trying to grow something different than what is found in the local nurseries and garden centers. I encourage people to push the limits of their environment by growing a variety of different plants. But remember, whenever growing plants, like redwoods, that don’t belong here you will need to invest more time, energy and money to get them to grow here.
Redwood tree in its natural habitat with man posed in front of it for perspective. From Wikipedia https://en.wikipedia.org/wiki/Old-growth_forest#/media/File:Redwood_M_D_Vaden.jpg
            Soils in containers become “exhausted” in a couple of years and must be renewed. I try to relate it to a fish aquarium. Periodically about one third of the water in an aquarium should be removed and replaced with fresh water. In a similar way, about one third of the soil in a container should be removed and replaced with fresh soil every 1 to 2 years.
Adding new soil to a container is like changing the water in an aquarium. Both rely on replacement to keep the arguments healthy.Picture is from Wikipedia https://en.wikipedia.org/wiki/Freshwater_aquarium#/media/File:Aquarium_60cm.JPG
            The second problem is the mature size of this plant. If you want this plant to grow for any length of time at all it should be grown in the ground, not in a container. These trees will get much too large to maintain in containers.
            The third problem is exposure. The south side of the home is much hotter than the north side. Plants that do not enjoy our desert environment perform much better on the north side, in the shade, than on the south side exposed to intense sunlight and heat.
             Even if the trees are protected from exposure by a house or other building, when they grow above this protection you will begin to see damage to the exposed parts of the tree in our climate and soils.
            A fourth problem is our tap water. About three fourths of it comes from the Colorado River and contains a high amount of salts. Redwoods do not like salts in the soil or the water and the salts will cause problems for these trees in containers.

            Your trees are probably “root bound” with spiraling roots that will never become established even in the best landscape soils. If you want to keep them, put them in the ground on the north side using improved soil and stake them for support. Enjoy them for as long as you can but realize that eventually they will succumb to our desert.

My Pomegranate Tree Produced No Fruit

Q. I have had a pomegranate tree for five years. The first three years it had fruit, even the first year I planted it. Last year and this year it has had no fruit. Can you tell me what to do for it? I prune and fertilize it the same way every year.

A. Pomegranates flower on the growth produced the same year the fruit is produced. In other words, unlike many other fruit trees, it flowers and produces fruit on new growth.
Pomegranate flowers

            It is very important to prune pomegranate before it begins to flower and avoid pruning during its growth. Pomegranate flowers and produces the best fruit on new growth coming from older wood.
            Some varieties of pomegranates, like yours, produce fruit when the tree is very young. Other pomegranates produce fruit after they get a bit older. As an experiment I would try not pruning at all this coming year and see what happens.
When pruning pomegranate leave four or five main stems at the base and remove all other sucker growth. The best pomegranates will be produced from this older wood.

            Another possibility could be the presence of some pretty nasty bugs such as the leaf footed plant bugs. You say your tree had no fruit but you did not say whether it produced flowers or not. If it produced flowers but no fruit than it is very likely the leaf footed plant bug was hard at work on your tree.
            If you have broadleaf evergreen trees such as bottlebrush (not pines), spray these trees during the winter months for leaf footed plant bug. These insects hide and feed during the winter months on trees that are evergreen or keep their leaves during the winter.
Bottlebrush in the winter with its very different looking seed capsules resulting from the flowers.

            These insects will be in full force when your pomegranate begins to produce fruit. Their feeding can cause fruit to drop from the tree at a very early age.
Safer is insecticidal soap is one example of a commercially made soap product safe to apply on plants.

            Soap and water sprays will control them if it is sprayed directly on these critters. Soap and water will not work if the tree is sprayed and you hope they come in contact with it.   Chemical sprays that appear to work well against this insect include pyrethrin sprays and those that contain the conventional insecticide Sevin.

Wednesday, November 18, 2015

August is Early for Chinese Pistache Fall Color in Las Vegas

Q. My Chinese Pistache was planted in my xeriscape front yard almost 4 years ago. Overall, I’d say it’s doing fine.  One thing puzzling is that the leaves started changing to “fall colors” around the beginning of August.  I don’t remember when it changed colors last or previous years but I think that’s a bit soon.  Again, the tree looks healthy to me but I thought I’d check with you to see if I should be concerned.

A. I agree, August is early in our climate unless there had been some unusually cold weather. Early fall color can be a sign of plant stress and this would be followed by unusually early leaf drop. The usual reason for this type of stress is either a lack of water or possibly watering too often.
Pistache with fall color.
            When watering, give the plant a lot of water all at once so the water drains to a depth of 2 feet, wetting all the roots. This will require that there are enough drip emitters and they deliver enough water if you are using drip.
            Chinese Pistache trees can get large, 40 feet, and the larger they get the more water they will need. Increase the amount of water they receive by adding more emitters every few years. It also helps if this tree has other plants growing around it that are receiving water.
            Do not water this tree daily. That is a big no-no. Watering deep, twice a week, would be plenty.
            Chinese Pistache will survive lawns but the soil under lawns is usually much better than the soil under rock mulch. When they are growing in lawns, this soil can be much more forgiving than the soil under a rock mulch that is getting watered too often.

            Chinese Pistache typically does not have a lot of insect or disease problems in our area so I would tend to think that this would not be the case unless of course you are watering frequently. This will cause big problems for this tree in the future.

Lawn Problems Basically Boil down to Three Types

Q. See if you can figure out what's happening to our lawn. It is dying. I'm very bad with technology so I'll have to send each picture in separate emails.

A. First of all, you did a very good job with the pictures. They all came through just fine.
Dying lawn from unidentified causes.
It is very difficult to determine a problem with the lawn from pictures. Lawn problems basically boil down to three types; disease, irrigation or insect problems. Sometimes it can be a combination of these.
            The pictures make me lean towards a disease problem. The first picture you sent had a combination of two grasses in it; tall fescue and there was a patch of what I think was ryegrass in the center of the picture. In that picture, the problem only affected the tall fescue and not the ryegrass.
The lawn has a color difference that you can see which is actually due to a difference in "texture" more than color. Different grasses have different "textures" due to the reflection of light on the leaf surface. This textural difference is a good indicator that more than one type of grass is present in "patches" and not mixed together.
            Lawns dying because of irrigation usually die in a specific pattern related to the irrigation sprinkler heads. Sometimes this pattern can be in between irrigation sprinkler heads and sometimes the pattern can be close to irrigation sprinkler heads. It depends on a number of factors including the nozzles that are used, operating pressure of the system and the design of the system.
            Homeowners that design their own irrigation system usually tell me it's not due to design because they "did it themselves". Good irrigation design is not something that most people can do. It is much more complicated than people realize.
Not the lawn in question. Grass suffering from drought will grass near the damaged area with a darker appearance than the rest of the lawn. This is because blades of grass either "roll" or "fold" in response to a lack of water and cause this darker appearance during times of drought.
            There are many landscape contractors who are skilled at irrigation design or they purchase the materials they need from companies that provide for them a professional irrigation design. Fly-by-nighters will not be skilled in this area.
            Poor irrigation coverage or management will contribute to disease problems and lawns. It is imperative that a good looking lawn has an irrigation system that is designed and installed by professionals.
            Poor irrigation management will contribute to disease problems. Never irrigate a lawn if there is more than three hours of darkness after the irrigation has been completed. A wet lawn sitting in darkness for more than four or five hours when temperatures are above 80° F has a very high probability of becoming diseased. In other words, "Never put a lawn to bed wet."
            I was not in town in September and I understand there was a long period of wet weather and warm temperatures. When I heard this, I was thinking this was an ideal condition for disease development in lawns.
            Disease problems may develop in a pattern or they may not. It really depends on the disease and to a lesser degree the management decisions applied to the lawn. Judging from the pictures you sent and what I have seen historically here I lean more towards a disease problem.
Diseases in lawns frequently develop some type of "pattern". Not always but it can be a good indicator that a disease is at work.
            What to do? Diseases will run their course until there is a change in the weather or management practices. If this disease problem began during September rains then the lowering of temperatures and low humidity stopped the disease from spreading further. It will probably do little good to apply any kind of fungicide now.
            We are getting to the tail end of the lawn planting season. I would make a decision to either replant the lawn from seed or sod but you should get it done by the middle of November at the latest.
            If you decide to re-plant from seed then mow the areas that are dead as short as possible and rake or power rake these areas until you see bare soil. Seed these areas with a good quality lawn grass. If your lawn is predominantly tall fescue, then select a good tall fescue blend and don't use a cheap one. If you are going to lay sod in these dead areas, rent a sod cutter and lay some new sod in these spots.

Backyard Wildlife in Las Vegas

Here are some pictures sent to me by readers of some wildlife they saw in their backyards recently. Remember the fires that occurred in the Mount Charleston area a while back. Water is a great way to attract all types of wildlife into your yard.
Bird at birdbath identified as Cooper's Hawk
One of the readers reported to me that she saw this Cooper's Hawk take out two pigeons.

Wikipedia on Cooper's Hawk
Wikipedia on great horned owl
Bird at birdbath identified as horned owl

Oleander Toxicity Probably Not A Problem for Vegetables When Composted

Q. I read you said recently that oleanders can be composted. Just for clarification, can they be composted for vegetable gardens since they are toxic?

A. Yes! They can be used for mulching and composting! Mulching is when the plant is chopped up into small pieces and laid on the soil surface. Composting is the controlled rotting of the plant so that it can be mixed in the soil as an amendment and fertilizer.
            There is contradictory information circulating on the Internet about the safety of oleander but the study below strongly suggests that there is no problem with it when it is composted and used for growing vegetables. They do warn that it is not safe to eat the compost (why someone or an animal would do that I don't know). It is also not a problem to compost eucalyptus as well.

            The smoke when burning oleander is a problem if inhaled. Although about 60% of our landscape plants are poisonous to some degree, oleander is one of the most toxic along with Datura spp. (a.k.a. Jimson Weed, Angel’s Trumpet, Thorn Apple), Nightshade, Castor Bean (Rosary Bead), Rhubarb, Moonseed, Lantana, Yew and Wisteria.

Clean up Debris to Reduce Skeletonizer Populations

Q. Although I was able to control the grape leaf skeletonizer all summer, I came back from a three week trip with 99% of the leaves stripped and dried up.  The grapes were picked in August and September. Should I still treat the vines with BT or just forget it since it is October and the leaves
would have soon turned brown anyway?
Skeletonizer feeding on the bottom side of grape leaves.

A. I would just let it go at this point. The only thing I worry about a little bit is regrowth (new leaves produced) because the temperatures are still warm. Regrowth will drain stored food reserves from inside the plant.
            These reserves are used for next year’s production but there should be plenty of “food” left even if it regrows this fall. I would not worry about it if that happens.

            Make sure you cleanup the leaves at the base of the plants. This is where the pupal stage (cocoon) will overwinter and if you do not cleanup this debris the attack on the plants next year will be earlier and more intense. The adults are winged moths so they will move from neighbor’s vines to neighbor’s vines. 

Curled Leaves on Pomegranate

Q. Our pomegranate tree has been planted for 5 years. We've had some fruit the past 2 years.  Lots more this year. I just spotted one already split with critters on it. The leaves look shriveled. Gave it fruit tree fertilizer and an extra watering. Any other suggestions would really be appreciated.

A. I looked at the pictures you sent to me and your pomegranate does not seem to be very full. The reasons they tree may not have filled out is because of the shade or not enough light during the day, not getting enough water or not fertilizing at the beginning of the growing year.
            Don’t worry about the curled leaves. This can be fairly common on pomegranate.
            They like to be deep watered just like any other landscape tree or shrub or fruit tree and watered about as often as well. If you want good production, don't treat them like a cactus. So in short, fertilize the tree in late January or February and start weekly irrigations the first week of
            I would construct the basin around the tree about 3 feet in diameter and 3 to 4 inches deep and fill the basin each time you irrigate. If you are to use drip irrigation, and they will perform good on drip irrigation if they're getting enough water, then make sure you have about four emitters and you run them long enough to deliver the water they need.
            The critters you see are leaf footed plant bugs and normally soap and water sprays would be enough to knock them back but you'll have to apply it weekly to the undersides of the leaves and all over the foliage.

            Pyrethrins sprays will also work on them. And if you are hard-core, the insecticide is Sevin will kill him but don't spray when the plant is in flower and spray very early in the morning or at dusk when bees are not present. I hope this helps.

Friday, October 9, 2015

What Caused Jalapeno Leaves to Be Stripped from My Plant.

Q. I went away for three days and when I returned all the leaves were stripped from my jalapeƱo plants. Do you know what did this?

A. Leaves stripped from vegetable plants is usually because of their tomato hornworm. Tomato hornworms are large caterpillars with the spine sticking from their rump. They can come in a variety of colors but we usually see green ones.
            They are voracious eaters and can remove leaves from plants at an alarming rate. They also leave behind a lot of large feces that could be confused with mice.
            They select only tender tissue and may leave behind more woody stems because they are not as delectable. When plants are very young and tender, they will consume the entire plant.
            You do not see them during the day because they hide and come out to forage at dusk and during the nighttime. To find them, go out at dusk with a flashlight or in the early evening hours.
            Another interesting way to find them is using a black light, the same way to find bark scorpions. Hornworms shine with an eerie green iridescence under a black light.
            Your plant will recover but you don’t have much time left for pepper production. When leaves are removed this stimulates the plant to produce new leaves from existing buds in the crotch or axil of the leaf. The problem is now the plant will focus on producing new leaves first rather than flowers and fruit.
            Protecting your plants from these creatures is easy to do by going out at night and removing them by hand. Protect plants with sprays of Bt or Spinosad which are considered organic controls. Just about any vegetable insecticide will control them as well.

Pine Top Dieback Means Damage Near Top

Q. The top of my pine tree died.  Bottom branches look as healthy as ever, green, supple new growth on all of them.  It is about 20 years old.  Its watering has been successful for my 14 years in this house, infrequent and deep - it has options to gather additional water from adjacent areas (lawn and garden) if it wants. Why did it die?   Can I remove the dead top?  And what will happen? 

A. I looked at the picture and I tried to identify the tree. The needles are not very long so it did not look like one of our common pines such as Afghan or Mondel pines. It actually looked like a spruce from the branches and the needle length. The kind of tree is very important in determining what caused the problem.
            Whenever we have a portion of the tree die and the rest of the tree appearing healthy, it usually pinpoints the problem at the trunk or limbs where the green foliage is closest to the brown or dead foliage.
            If I were on site I would get a look at the trunk or limbs at the juncture between healthy and dead areas. I would look for mechanical damage in that area. I can’t tell you why there would be mechanical damage but that’s what I would look for. This is not something we would normally see with pine trees.

            If this is a spruce and not a pine then it might be heat stress. Spruce trees cannot tolerate our climate and soils very well and have difficulty lifting water from the roots to the upper limbs. If this is a tree that is not tolerant of our hot dry climate or desert soils than this could be drought at the top of this tree causing it to die back.

Control Root-Eating Grubs Organically and Conventionally

Q. I found grubs in the dirt with my plants. I put some Triazicide around the plants. Will this help?

A. Triazicide is a conventional insecticide, found at any nursery or garden center, which is very effective at killing grubs. The major advantage of conventional insecticides like this one is the residue or residual left behind after the application. For those preferring organic methods, this is also a major drawback.
            There are organic alternatives to grub control which are very effective. These include pyrethrum applied as a soil drench for an immediate kill, milky spore bacterium and beneficial nematodes. Milky spore bacterium and beneficial nematodes also give you long-term plant protection from grubs.
            In your case, you need something to kill the grubs. Once you kill the grubs, it may be no longer necessary for a product like Triazicide to hang around in the soil.
            A residual product like Triazicide becomes important when protecting valuable plants from an infestation which may be imminent. In cases such as these, mark the calendar when the insect threat might occur and apply this type of product two weeks to a month before this date.
            I would not use this product around food crops but lawns and ornamentals are more suitable. But always read and understand the methods of application stated on the label.
            Triazicide comes in several different formulations (liquid concentrate, granules, ready to use liquid, etc.) and each formulation is applied a little bit differently. Basically the poison is applied to the soil surface and water is used to wash this poison to where the grubs are actively feeding. Applying too much water can move the product beyond the area where it is needed.
            Manufacturers want you to be successful with their products so you will use them again and recommend them to others. They try to provide the best information possible so that you are successful.
            Be cautious around your outside pets like dogs and cats since any insecticide, organic or
conventional, moves easily from the soil surface, through the pads of their feet and into their body. I would not let them walk in the area until the surface where it was applied is totally dry.

When to Cover Winter Tender Plants in the Mojave Desert

Q. When should we cover Pygmy Palm, Bougainvillea and other plants that will freeze here in Henderson?  I have burlap to cover them.

Bougainvillea freeze damage
A. Both of these plants can tolerate temperatures to near freezing and they don't seem to have problems at temperatures below 45° F that causes chilling damage to some plants. Some tropical plants such as tomatoes may show chilling damage to fruit at temperatures below 45° F. This is why it is best to not refrigerate tomato fruits.
            It seldom freezes in the Las Vegas Valley before Thanksgiving. After Thanksgiving you might expect freezing temperatures at the higher elevations such as in Summerlin or in very low spots in the Valley where cold air collects. In Henderson, this might be in the old Pittman area or along the wash.
            Cold air, being heavier than warm air, settles into low geographic areas. Cold air tends not to settle on gently sloping land or hills.
            Freezing temperatures are more frequent where plants are exposed to wind. Plants growing along major streets tend to freeze more often than those in protected backyards. Major streets are urban canyons that channel cold wind in the winter. Backyards are more nestled away from these exposed urban canyons.
Sehgal palm cold damage
            Plants growing close to brick or cement walls that face West or South are less likely to freeze than plants growing further away unless wind is involved. Brick and cement walls exposed to the sun store heat during the day and radiate this heat at night keeping the plants a few degrees warmer. If wind is involved, it removes this radiant warmth making these plants more susceptible to freezing temperatures.
            Bottom line, when the weather forecast is for freezing temperatures, cover the plants with an old sheet, blanket, or in your case burlap, before nightfall. Drape this covering over the soil or any surface that can radiate heat at night. Remove this covering the next morning after temperatures are above freezing.
            In open areas, expect freezing temperatures after Thanksgiving and up to March 1. In protected areas, expect these temperatures anytime between mid-December and mid-February but watch your local weather forecast closely and adapt this recommendation accordingly.

Imidacloprid a Problem for Pollinating Insects?

Q. Do you recommend using imidacloprid in the grass to kill grubs? Does it harm pollinators? What would you advise?

A. That particular chemical is suspected of possibly damaging pollinators. Nothing has been conclusive about it but logic tells us that if we have a systemic insecticide that can persist in a plant for 12 months that it is possible this chemical may be in flowers, pollen or nectar. We just don't know.

For this reason I tell people if they are going to apply it to plants that bloom then apply it immediately after they have finished blooming. I also tell them that it is safest to use on plants which do not have flowers that attract bees. Lawn grasses do not attract bees so I don't consider that to be a problem for pollinators.

Even though it is labeled for fruit trees, I would not personally use it on fruit trees if I am planning to use the fruit. If I were to apply it to fruit trees or any ornamental tree that has flowers that attract pollinators, I would not apply it until after bloom until we have more conclusive evidence that it is not a problem with pollinators. That's what I am currently recommending regarding this product.