Xtremehorticulture

Xtremehorticulture of the Desert

Controlling Spider Mites in Italian Cypress

9 Comments / Spider mites in Italian Cypress, why are there branches dying in my Italian Cypress, why does my Italian Cypress look dusty, why is my Italian Cypress dying /

Q. I have three Italian Cypress trees that are 20 feet tall.  I have a problem with spider mites and want to know the best way to reduce their populations.  I started spraying them with high pressure water and it got rid of all the webs. Since the trees are so tall I cannot effectively apply a pesticide using my Ortho sprayer and garden hose. Webbing in Italian Cypress does not always mean spider mites. You need to do the paper test explained below to see if mites are the problem or not. A. How did you confirm that the problem is spider mites? They are easy to misdiagnose and there are problems that can appear like spider mite problems and they are not. For instance, not all spider mites create webbing and not all webbing in Italian Cypress means it has spider mites. You can find webbing in Italian Cypress from spiders that are actually good guys and helping you out. Spider mites normally occur during hot weather. We seldom see them during cooler weather. An Italian Cypress which has spider mites will have the green needles or foliage beginning to die or turn color, usually grey first. If I look at these needles they will have a dusty appearance if spider mites are present. Spider mites are extremely small. This one is highly magnified. They are about the size of the dot at the end of this sentence . This isn’t dust but these are dead spider mites that litter the surface of the foliage. If I see Italian Cypress with dusty needles or foliage I begin to think they might have spider mites. The way I usually determine if spider mites are the problem is to take a white piece of paper and slap the branch of Italian Cypress against the paper pretty hard. This dislodges the spider mites from the foliage and onto the paper. I then hold the white piece of paper in bright sunlight very still for 15 to 30 seconds. If mites are present, I will see tiny little dots the size of a large period crawling around on the paper. If I brush my fingers lightly across this moving dot on the paper, I will see red smears on the paper. If the Italian Cypress appears damaged, the foliage or needles appear dusty and I get red smears on the white piece of paper I will conclude the damages from spider mites. Soap and water sprays are somewhat effective if done on a regular basis (couple of times during hot weather or after a dust storm) as a preventive. Otherwise you would have to apply a miticide effective against spider mites for good control. You would apply two applications about ten days apart to control the hatching of young mites from eggs which are not controlled with the first spray. Unfortunately this would require that you spray the entire tree if mites are a problem. It is really hard for homeowners to spray much above 10 feet. I do not know of any miticides that you can apply to the soil and get good control. First, make sure the tree has spider mites and that is the problem. Insecticidal soaps are good first choice but they are not extremely effective in controlling this pest. If you do get it confirmed that it spider mites and they are out-of-control, you will have to spray miticide. Watering Italian Cypress too often causing root disease problems can give them a similar appearance as branches begin to die. Spraying trees above 10 feet is difficult for homeowners. Pest control operators and arborists have equipment to do this.

Controlling Spider Mites in Italian Cypress Read More »

We Have Holes in Our Tomatoes!

Leave a Comment / Tomato fruit worm, what is causing holes in my tomatoes, why are my tomatoes /

Q. I have Early Girl green tomatoes with round holes in three of them. Otherwise plant is in great shape. Other fruits on plant OK. . A. That is feeding damage probably by the tomato fruitworm. Applications of Bt or spinosad should slow them down and are “organic” controls.This is basically the same “worm” that attacks the ears of corn by laying its eggs on the new silk coming from the forming ears. The tomato fruitworm is probably the most damaging pest to tomato fruits. As the name implies, the damaging part of this insects lifecycle is the “worm” stage or more properly called “larva”. Click here to see the larva or immature form before it becomes a moth They don’t all come in one color so they can range in colors from pale yellow, to red, green or even brown with pale stripes down its length. They are about an inch and a half long when fully grown but they can be smaller than this if they are not yet mature. Unlike hornworms which are pretty easy to spot during the day or at night  with a black light because they glow green,  fruitworms you wont see until you see damage to the tomato fruit. With your black light you can go scouting for hornworms and scorpions at the same time! The adult of the fruitworm is a night-flying moths that ranges in color from tan to brown with orange in it. They are about 1 to 1 1/4 inch across their wingspan. Click here to see the adult moth Because they fly at night that’s when the egg laying occurs.They like to lay their eggs on tomato leaves close to green fruit or they might lay them on the leaves on the outer edge of the plant if the plant is dense. They are flying now and have been flying for quite some time. Click here to see a close-up of an egg The eggs that they lay are very difficult to see because they are so small.The eggs are white when first laid and then develop a brown stripe or mark just before they’re ready to hatch. First they begin to feed on leaves before they attack the fruit. They prefer to feed on green fruit and the damage that they create by tunneling into the fruit causes the tomatoes to ripen more quickly. The fruit is pretty well demolished once they enter and feed and move on to a new fruit. Shining a white light or black light against a white sheet at night is an easy way to see if they are flying.  You can try it now and you will probably attract some but the best time is when tomatoes begin to flower so you can time your spraying. You can also use pheremone traps. Black light or even light traps serve as a good indicator when these guys are flying and will be a problem in the garden in the future. This is a cool way to look for them and great to show kids and grandkids.

We Have Holes in Our Tomatoes! Read More »

Why Are My Tomatoes Not Ripening?

Leave a Comment / why are my grapes not growing, Why are my tomatoes not ripening /

            This cool weather has caused some unusual plant problems we normally do not see in the hot desert. One reader contacted me to let me know that his tomatoes were not quite the size of a tennis ball, still green and didn’t seem to be growing anymore. Tomato growth and fruit ripening slow during cool night temperatures             Another reader told me his newly planted grapes were not growing. Both readers wanted to know what to do.             The answer to both is to wait. Both of these plants love warm weather. In fact, grapes love the heat. Our nighttime temperatures have been in the 50s and 60s. Most plant growth occurs at night, not during the day. Tomato gets chilling injury at 45° F. Be patient. It will get hot. Tomatoes will ripen. Grapes will grow an inch every 1 to 2 days when temperatures are above 100° F. All we need are warm night temperatures.

Why Are My Tomatoes Not Ripening? Read More »

Shade Reduces the Flowering of Pomegranates

Leave a Comment / how to increase flowers of pomegranate, how to increase fruits of pomegranate, Why is my pomegranate not flowering /

Q. I’m not getting a very big crop of pomegranates this year. They are about 6 years old. We have a large ash tree in the yard which throws some shade but the pomegranates both get morning sun.  I heard they don’t require much water so I was worried they were getting too much. Then the Homeowners Association switched from grass to desert landscaping this past year. Flowering of pomegranates requires the tree to be in full sunlight A. To produce fruit, pomegranate need at least six hours of sunlight but does best in full sun. As shade increases on pomegranate, the number of flowers and fruits decrease. Switching from lawns to desert landscaping reduces the overall amount of water pomegranates are receiving. This will affect overall growth, flowering and fruit production. Pomegranates produce flowers on new growth. If you are getting lots of new growth and there is enough sunlight there is no reason you should not be getting lots of flowers at that age. The key will be the number of flowers it’s producing. If the tree is not producing flowers of course it can’t produce fruit. To stimulate flower production they need the same amount of water as other fruit trees. This plant is very drought tolerant but it needs water if it is to be productive. The amount of water depends on its size. The frequency of watering is the same regardless of size. A six-year-old pomegranate should be at least 4 or 5 feet across. Its height depends on how it is pruned. An indicator it is getting plenty of water is the density of the canopy. Your pomegranate tree or bush should be dense enough you would have trouble seeing through it. If you are not seeing much new growth and the canopy is not dense, this is usually an indication it’s not getting enough water. Of course production increases if fertilizers are applied as well. Surface wood mulches help retain water in the soil and improved growth and production of these plants.

Shade Reduces the Flowering of Pomegranates Read More »

Grapes like the Heat, Grow Slowly during Cold Nights

Leave a Comment / Why are my grapes growing slowly /

Q. My newly planted grapes aren’t really growing fast and are a bit more yellow than dark green. I am wondering if I need to water more. I am only watering two times a week or water less. Or if I need to add something to the soil? Or do nothing and stop worrying? A. Grapes love the heat. It is probably just not warm enough. Watering twice a week is right when temperatures are beginning to warm. Apply about five gallons each time you water newly planted grapes. Put a steel stake next to them or a piece of rebar and tie them tightly to it so they are straight. Use the stretchable green nursery tape. Do not use wires. If you are planning to trellis these grapes, remove all leaves along the trunk except the new growth at the tip. You do not want side shoots to develop along the trunk unless you are growing it in a tree form. Grapes grow slowly during cool weather The leaf yellowing could be caused by cool nighttime temperatures or a lack of nitrogen fertilizer. Apply nitrogen fertilizer once a month to the soil around the trees and water it in. Do not apply closer than about 12 inches to the plant or you could burn them or worse. I see from the pictures you sent you have a lot of rock mulch surrounding your fruit trees and vegetables. Our soils have horribly low amounts of organic content, some of the lowest on the planet. Grapes, all fruit trees and vegetables including strawberries do not like rock mulch at all. This will be a problem in the future. They like “organic” soils, not rock or mineral soils. The small amount of wood chips you have spread a few inches around your plants will not help them at all. Wood surface mulches need to be at least 3-4 inches deep and a distance of at least three feet from their trunks. Keep wood mulches several inches away from the trunks of young trees and vines.

Grapes like the Heat, Grow Slowly during Cold Nights Read More »

Gopher Control Includes Several Alternatives

1 Comment / How to control gophers /

Q. I live in Sandy Valley and will be building some raised bed planters in my backyard. I have seen gopher mounds all over the property and wondering what is the best way to get rid of them before I start this project. One neighbor says they are so prevalent on the north end of the valley they ignore them altogether. Gophers make pretty big holes and you can find fresh soil pushed from the excavation. A. Gophers are tough to control. The options are to kill them, exclude them from desirable plants or catch and relocate them. When gophers have other food sources in the neighborhood using repellent plants in your garden might work since your neighbor’s plants will then seem more delectable.             When gophers find a food source, they make more gophers. Your raised beds will encourage them to set up a base camp, living quarters and a dining commons. The bottom line is they are attracted to your water and the soft, juicy succulent plants you are growing. There are baits and poisons you can use but you’ll have to be very careful not to poison other animals in the process. Your best option is probably to exclude them from your growing area with a wire mesh barrier. You would need to move all your susceptible production into raised beds and place wire mesh at the bottom of the bed before filling it with garden soil. It is best to read through this for your options. http://cesonoma.ucanr.edu/files/27165.pdf

Gopher Control Includes Several Alternatives Read More »

Jujube Good Choice for Desert Production, Not Hachiya Persimmon

4 Comments / hachiya grow in las vegas, Las Vegas, Mojave Desert, Will jujube chinese date grow in the desert /

Fruit of one variety of jujube Q. I just bought a new house with big yard at Summerlin. I am Asian and there are three trees I want to plant most but I don’t have any experience; Jujube, Hachiya persimmon and white saucer peach. I read some of your articles and decide to ask your advice before I take the action. A. Jujube, or Chinese date, grows extremely well in our climate and you will have a lot of success growing it here. The biggest problem is its invasiveness. Jujube suckers from its roots in new locations wherever there is water. These can be distances of 5 to 20 feet away from the mother plant. Over time, you could have a forest of jujube from a single plant. Just keep the suckers eliminated when you see them. Sadly, Hachiya persimmon does not perform as well here as Fuyu and other persimmons. We have trouble getting good fruit retention (fruit staying on the tree) after the fruit has set. Plenty of blossoms but the fruit drops when it gets about ½ inch in diameter and the tree produces only a few fruit. I would suggest trying different varieties of persimmons such as Fuyu, Giant Fuyu, Coffeecake, and others). The white, flat peaches perform very well here with a very high sugar content and excellent flavor. I would suggest donut peaches such as “Stark Saturn” or “Sweet Bagel” varieties. These peaches may also be called saucer or peento peach. If you keep your trees healthy by planting with plenty of compost mixed in the soil at planting time and covering the soil surface with wood mulch you will have fewer problems. You can always email me with specific questions.

Jujube Good Choice for Desert Production, Not Hachiya Persimmon Read More »

Salt Damage to Peppers Can Be Managed through Irrigation

Leave a Comment / increasing yield of pepper because of salts, salinity damage to pepper how to correct salt damage, Salt damage to peppers /

Q. We are small farmers owning 2 acres of land in India, We have just seen your opinion on RO water for horticulture crops. We are growing roses and colour capsicum under poly greenhouse cultivation. Our ground water electrical conductivity level (salinity) is too bad that it comes to 1.8. So our plants came to death condition. We heard about reverse osmosis system and fixed it to our farm. By this system leaves shrinkage and nutrient deficiency had risen. So we are pleasing to suggest your idea about it. We are looking for your grateful suggestion. A. Pepper plants are very tolerant of this level of salinity. It only becomes a problem if we let the soil becomes excessively dry or if the drainage of the soil is very poor and the water drains slowly. Improve the drainage of the soil and irrigate so that the soil never dries to less than 60% of its water content. With a little bit of experience, you can determine this just using your hands and feeling the moisture content by squeezing it and using your fingers. The kind of salts that you have in the soil will dictate if you were to use soil additives such as gypsum or not to help flush the salts from the soil. Sending a soil sample to a soils laboratory to determine which salts are present would be very helpful. Generally speaking we start to see yield reduction in pepper at about 1.5 dS/m (mmhos/cm). You are close to that threshold at 1.8. I think you would only need to dilute your irrigation water maybe 20% with RO water to get below this threshold. New Mexico’s advice on salt damage to peppers Another option is to water with your irrigation water and then flush salts using an irrigation cycle using water with lower salts. Use these in an irrigation cycle of salts/low salts/salts/low salts/etc. Monitor your drainage water for salt content. Monitoring your drainage water and recording it regularly will help you with managing salts (flushing, etc.) Two types of salt damage occurs to plants; one is due to total salts (EC) and the other is due to the type of salts (specific ion effect). Particularly damaging are sodium, chloride and boron. If these salts are involved then this might mean a very different problem than just salts in general. What to do? If it is possible, determine which salts are present and not just the level of salinity (1.8).  When irrigating never let the soil or substrate dry out too much.  With high salts you should be irrigating frequently with a smaller volume of water. This prevents the salts from becoming too concentrated.  If you can over irrigate and flush salts from your soils make sure you over irrigate by about 20% to keep salts moving through your soil profile and maintain a steady state of salts and prevent the buildup of salts. Depending on the type of salts in your irrigation water you will see different nutrient deficiencies. Note: This question was from farmers in India. Potable water, water in the Las Vegas Valley coming from the tap, is close to this level of salinity or salts. This is because a large percentage of this water comes from the Colorado River unless you are on well water. Salt levels of our native soils here in the Las Vegas Valley are 25 times this level. Water management is very important to control salinity.

Salt Damage to Peppers Can Be Managed through Irrigation Read More »