Q. Can you give some tips to on how to survive this latest bout of heat? Is it simply too hot right now for plants? Is shade cloth the answer? A. It has been hot these past few weeks and very stressful for many landscape plants. There has been a combination of high temperatures, intense sunlight, very low humidity and windy conditions. Just like us, healthy plants have the best tolerance to the extremes of heat and cold. But water and fertilizer can be a killer if too much is applied.             Shade cloth is helpful in some situations but it is usually for vegetables. Use shade cloth to manage the intensity of sunlight and reduce sunburn on tender vegetables. Shade cloth providing somewhere between 30 to 50% shade is used with these plants. Otherwise, rely on leaves of plants to provide their own filtered light. Avoid watering trees, shrubs or any plants that are woody every day. Try to give these plants at least one day of rest, without irrigation, between waterings. Some landscape plants have roots that suffocate easily if the soil contains too much water. These plants seem to “die overnight” when watered daily or the soil remains wet. Mulch helps. Mulch of any kind, whether it is rock or wood chips, applied to the surface of the soil helps cool it, preserves soil moisture and helps battle weeds. Rock mulch applied to the surface of the soil is best for desert species of plants. Woodchip mulch is best for non-desert species of plants. A surface layer of mulch can add one or two extra days between irrigations. A wet sponge drips water because it can hold no more.A sponge is moist after it has been squeezed. Water just before the heat. Make sure plants enter the heat of the day with their roots surrounded by moist soil. There is a difference between “wet” and “moist”. This is particularly true of plants grown in containers. These soils dry out faster than soils in the landscape. Plus containers warm their soils faster compared to landscape soils. Wet or moist soils warm up slower than drier soils.               Water lawns early in the morning. Apply lawn irrigations as close to sunup as possible but when still dark. Windspeed is usually slowest at these times. Never put a lawn “to bed” wet. Give the leaves a chance to dry off before it gets dark. This helps avoid lawn diseases.              Fertilizer can be applied now. You can apply fertilizers this time year but use half the recommended rate and apply it when temperatures are cool, during the mornings or evenings. Make sure dry fertilizers are rinsed into the soil immediately after they are applied. Lifertilizers can be sprayed on leaves but only during morning when temperatures are cool.               Some pruning can be done now. Light pruning can be done anytime during the growing season. Never use anything bigger than a hand pruner this time of year. Use saws and loppers only during late fall winter and early spring. Don’t remove too much. Always leave some growth to shade the trunk, stems and branches.

Q. When laying hybrid Bermudagrass sod, does it make sense to water two or three times on hot days?   A. Freshly laid bermudagrass sod should be watered once a day. Make sure the soil beneath the sod is wet and not just the sod itself. Bermudagrass is a very fast grower and loves the heat when it’s roots are in wet soil and there is plenty of nitrogen fertilizer.. Avoid sprinkling the sod just enough to wet it. It needs more water than that. This was tall fescue sod laid in the middle of summer on very hot, dry soil. The hot dry soil burned the roots of the sod causing dead patches like a disease. Fescue sod is hard to establish during the heat. Bermudagrass and other warm season grasses like St. Augustine or zoysia should be laid during the early heat of summer..             Water and nitrogen. Bermudagrass sod needs water and nitrogen fertilizer so that its roots can “knit” into the soil beneath it. When watering, make sure enough is applied to wet the soil several inches beneath it. As you begin mowing, increase the amount of water applied and try to water every other day during the heat. This forces its roots to grow deeper and the grass will become more drought tolerant.             Hopefully a phosphorus fertilizer was applied to the soil before laying the sod. If not, then apply one now. Use a single application of 16-20-0 at a rate of 2 to 3 lbs of fertilizer per 1000 square feet and water it in immediately after application.              Applying nitrogen fertilizer frequently. Apply nitrogen fertilizers once a month during establishment. Apply 21-0-0 at 3 lbs per 1000 square feet. Once the lawn is established in about 3 months, reduce fertilizer applications to three or four times per growing season.

Q. Our Acacia and other trees in our neighborhood in Mesquite, Nevada, have leaves that are turning yellow. Is this from all the heat we’ve had or too much watering?  This is citrus but leaf yellowing accompanied by scorching of the edges is usually a good indicator the plant is not getting enough water. The solution is not to water more often but to give it more water when you do water.Scorching and yellowing of the leaves can also mean some salt problems. Salt problems can happen when plants aren’t getting enough water. Flush the soil around the plant with high volumes of water a couple of times. A. This extended heat wave requires you to water more often. But water long enough to wet the soil deeply. Avoid watering daily, particularly trees and shrubs. It is not needed if you water deeply. It is better for the plants if you don’t. Instead, increase the number of minutes so that you can avoid watering every day.             Healthy plants can handle the heat. Leaf yellowing is not because of heat but because of either dry soils or soils that are continually wet. Continually wet soils can occur from daily watering. Watering desert adapted plants every day may cause their roots to “suffocate” from too much water.             Watering less often, but with larger amounts of water, forces roots to grow deeper and harvest water from greater soil depths.             Plants are lazy. Plants require more energy to harvest water from deep in the soil than from the surface of a soil. If water is applied to the surface every day, these lazy plant roots “slurp” up the surface water and hardly touch the deeper water, if there is any.             If water can be found deep in the soil and the surface of the soil begins dry, tree roots will be forced to grow and harvest water from these deeper, wet soils. This deeper growth improves anchoring of the tree and reduces “blow over” during high winds.             If you are going to make a mistake when overwatering, make the mistake of giving the plant too much water rather than watering daily.

Q. What is the optimal watering and fertilizer schedule for desert pines? I started taking care of a large horse property two months ago. Many of the trees were in distress from lack of water and fertilizer. I’ve been watering about 5 gallons per tree per day and the trees have responded with new growth and color. A. Five gallons of water per tree per day is not much. Watering this way forces tree roots to grow along the surface of the soil. It does nothing to encourage deeper growth. Deeper root growth is important to  prevent them from blowing over during high winds. It is also important for their tolerance to dry conditions.             I understand they were in bad shape but with the amount of water you are giving them they will never become lush and dense. The density of most trees increases with increasing amounts of water. Tree density decreases with lesser amounts of water.             Larger trees require more water. Smaller trees require less water. You can decrease their water use through selective pruning to control their size if their water use is a problem.             It is difficult to estimate how much water they need. But the amount of water they will need in one year is roughly equivalent to the volume of water 4 feet deep under their canopies.               Let’s do some math. Estimate the cubic feet, 4 feet deep, under the canopy.First calculate the area under the canopy. Use 3.14 x half of the diameter squared. If the diameter of the canopy is 20 feet, multiply 3.14 x 100 which is 314 square feet. Now multiply 314 x 4 to get the cubic feet of the area 4 feet deep. The cubic feet of water needed by EACH pine is 1256 cubic feet. Multiply the cubic feet by 7.48 to estimate gallons of water. This will be about 9320 gallons of water consumed by each tree this size each year. About 2/3 of this water, or about 6100 gallons, will be used from May through October. The remaining 1/3, about 3100 gallons, will be used from November until May.  Water less often but with more water. Depending on the soil you have, water once or twice each week during the summer months. Water less often than this during the fall, winter and spring months.Give each tree enough water so the water will drain at least 2 feet deep around the tree. It is very important to give these trees the same amount of water each time you irrigate them. A surface mulch of wood chips in these basins, at least 4 inches deep, would help these trees considerably.   You can’t see it very well but there is a basin around this pine tree. I would make this basin deeper so that it will hold at least 2 to 3 inches of water. Large basins may require 2 bubblers or 2 rings of drip emitters around the tree.             Trees of this size might be best irrigated using a basin around each tree trunk. The trees are watered by filling this basin. The basin should be constructed at least half the size of the trees canopy.It does not have to be round but should be located where you want most of the roots to grow. If these trees are close together, you could group 2 or 3 trees with a shared basin. Just make sure each of the basins are level. The basin is also a convenient place to apply fertilizer or horse manure, in your case, once or twice a year.

Q. One of the pine trees in my backyard has developed a split in the bark and is oozing some sap. The trees were planted about 10 -12 years ago and are now 12 -14 “in diameter. Is this something we should be concerned about? None of these pictures are from the reader but it is easy to see that pine trees, when they are injured, produce an abundance of sap. A. If the trees appear otherwise healthy, most likely not. When pine trees have wounds, it is normal for them to “leak” sap. It is their way of healing from wounds.When you do see sap from pine trees it is an indication that there was damage done.             Make sure the tree is getting enough water. Also, make sure it is not watered too often.Having adequate water speeds the recovery from wounds. The trees canopy is a quick way to know if your pine tree is receiving enough water. Dense canopies with lots of new growth is a good indicator enough water is being applied.             Water these trees deeply but infrequently. In other words, give them big drinks of water and then hold off as long as you can before the next irrigation. Deep irrigations 2 or 3 times a week should be enough.

 This was an exchange regarding a tomato problem. The first exchange..Q1… I did not have pictures to go on. The second exchange Q2….I was sent pictures. Pictures help alot!! Still not sure what it is exactly and only a plant pathologist would know for sure but sanitation recommendations and buying transplants from a good grower are still good suggestions….Xtremehort Q1. Most of my 12 tomato plants have developed. A light brown appearance on their leaves. It looks kind of like they have dirt on them.  The fruit all looks normal. Any suggestions? A1. It is difficult to identify a problem without seeing it unless something just jumps out at you. In this case it doesn’t. But let me tell you how I would approach it. From your description, I don’t think it’s a disease problem. It could possibly be an insect or spider might problem. re{ you mention dust I would spray the leaves with a soapy water solution. Insecticidal soaps are my first choice. My second choice is to make your own using a liquid Castile soap and water at a rate of about 1 tablespoon per gallon. Spray both the tops of the leaves as well is the bottom of the leaves. Soaps are very lethal to insects. They kill good ones and bad ones equally and don’t discriminate. In your case I don’t think these are good insects. I am leaning towards spider mites if it has been hot and dry lately Or if you sprayed an insecticide on them lately. Make sure that you feed tomato plants once a month lightly with a fertilizer. Either apply it to the soil or sprayed on the leaves during early morning or early evening hours. Q2. Mine is a backyard garden with limited space.  I grow six plants in the ground and 4 more in big pots. I add a couple cubic feet of garden soil every year. Don’t have many options. I suspected the issue came from the nursery. They are into quantity rather than quality. So, is there anything I can do at this point to treat the plants? Here are two pictures, one taken in the sun and the other in the shade. Thanks for your response. A2. Thanks for the pictures. It helped. Notice how the brown spots are closely associated with the leaf veins. That is important and indicates to me a tomato disease problem. It is difficult to tell from pictures but I am leaning towards bacterial canker. It is not one of the more common tomato diseases that we see in vegetable beds like early blight. I believe this disease came with the transplants when you bought them. If you grew your own transplants, then the seed was contaminated or the beds where they are grown were not thoroughly clean when you planted. Another possibility is that tomatoes were grown in that location in previous years. When you continue to grow the same vegetables in the same areas year after year, diseases tend to build up in the soil and it’s difficult to grow plants in that location Of the same family. This is why it is important to rotate vegetables into new locations every year. Do not grow anything in the tomato family in that spot for the next 3 to 5 years. You can grow vegetables in different families there such as the cucumber family, onion family, carrots, beets but not tomatoes, peppers, eggplant or potatoes. They are all in the tomato family. If the tomato plants are still alive, I would cut them back and remove about one third to half of the entire canopy of the plants. Don’t give them a butch haircut but try to remove one entire stem where two come together. You want to open the canopy of the plant for air movement but you don’t want to open it too much and cause sunburn. It will be a little tricky. Once you do that, lightly fertilize them and deep water them. If you prune them correctly, you should start to see new growth coming lower on the stems. Protect this new growth. Diseases can be moved around on tools, your hands, clothing so make sure that everything is sanitized with 70% ethyl alcohol. Be sure that no debris, no rotting fruit, no plant parts, no weeds are present in the area. Otherwise, pull these plants out and get them out of the garden area. Sanitize all your tools. Cleanup all debris in the garden. Replant with tomato seedlings in mid July to August 1. Or start some tomato plants directly from seed yourself in mid-July for a fall crop. Tomatoes will start setting fruit again when temperatures drop below 95 ° F consistently.

Q. When it comes to freshly laid hybrid Bermuda, does it make sense to water  two or three times on hot days, in that the roots presumably having grown  into the soil, thus you need to keep tin amount of soil moist, coming from  the sod farm. Commercially sod can be laid in large rolls, similar to carpet rolls. A. Some of the hybrid bermudagrasses make the best lawns in the world. But they need more maintenance than fescue. They can handle alot of abuse during establishment. You should get it established in two to three months during the summer. It just needs water and nitrogen fertilizer applied regularly. Freshly laid bermudagrass needs watering only once a day. But when you water it, water it thoroughly. Bermudagrass is warm season, subtropical, while fescue is temperate and a totally different “animal”. Make sure enough water is applied to wet the soil 8 to 10 inches and apply nitrogen once a month. Don’t apply the water lightly and wet only the sod. Not true of tall fescue sod. I would not lay tall fescue sod in this heat. Bermuda, yes. Hopefully you put down a high phosphorus fertilizer before laying the sod. If you did not, then apply one now. Use 16-20-0 at a rate of 2 to 3 lbs of fertilizer per 1000 square feet and water it in immediately and thoroughly. At this rate it won’t burn during the heat. Otherwise apply 21-0-0 at 3 lbs per 1000 every 4 to 6 weeks during establishment. Be ready to mow this sod twice a week with this watering and fertilizing regime. Depending on the Bermuda used, you can use a rotary mower on many of them. Otherwise it should be a reel-type mower. Once established in about three months then cut back to normal fertilizer applications of three to four times per growing season.

Q. Some advice on watering please. This is my first Las Vegas summer in a new to us house about 12 years old. Lots of lantana, Texas rangers, bottle brush, small short palms and other desert shrubs.  Everything is on a drip systems, no lawn.  I am not sure how often, how long to water.  How many days, once or twice a day, how long each time. My drip are adjustable. Valve box with valves A. There are 3 things you need to know to use any irrigation clock or controller; the time of day to water, the days during the week to water and the number of minutes to enter for each station or valve.  Irrigation controller or timer. Three pieces of information are entered: days of the week on or off, how many minutes to run each valve and the time they begin. Most drip irrigation systems are a mess because the person who installed them didn’t know what they were doing or, if they did, they have been altered over the years by landscape maintenance companies or the owner. You have what you have… unless you are willing to go in and totally redo the system ….which most people aren’t.   Each colored wire connects to a separate valve. The white one is “common” to each valve as well. Your irrigation clock requires you to set each irrigation valve separately. Your irrigation system might have lots of different plants on the same irrigation valve. That’s very common. If that’s the case, you have to find a happy medium for everything on that valve or redo the irrigation system. Most plants are quite adaptable to an irrigation schedule. The biggest plant problems occur when homeowners water daily on everything either because they are lazy or nothing seems to work for them.   Irrigation emitters, drippers, should be distributed under the canopy of a plant to supply their roots with water. Lots of emitters are needed to keep large trees upright so they don’t fall over. Time of day. If any part of your irrigation system sprays or “sprinkles” water into the air where the wind can move it around, this should be set for early in the morning and end by sunrise. If it’s drip irrigation, it can be done anytime but is usually best if it comes on during the day as it is getting warm and, if a 2nd irrigation is needed that day, to come on late in the afternoon or early evening. Days of the week. The days of the week depends on how shallow or deep the roots of plants are growing. Shallow rooted: lawns, vegetables, annual flowers. Daily when it’s hot. Vegetables and annual flowers might require a 2nd irrigation later in the day on days it’s really hot and windy. Lawns should never require a 2nd irrigation on the same day. If they do, then they should be aerated with a lawn aerator and encouraged to grow their roots deeper.   Gasoline driven core aerifier Rooted to a medium depth: woody shrubs up to 3 to 4 feet tall, woody vines and woody groundcovers. Examples might include roses, lantana, mock orange, etc. Every other day to every 3rd day when it is hot. When it is really hot you might have to irrigate every other day but try to avoid watering daily if possible. Under some circumstances, you might find it necessary. Deep rooted trees and shrubs: These are trees and large shrubs that provide shade or beauty. Whenever possible, trees and shrubs that originate from desert climates should be on a separate valve. This almost never happens. Examples include Mulberry, Olive, ash trees, Purple leaf Plum, Fruit trees, etc. Once or twice a week during the heat of the summer. In some cases, 3 times a week. When fruit trees are producing fruit they should not be water stressed and require an extra irrigation per week when fruit is being produced. Most landscape trees and shrubs can be water stressed a little bit between irrigations. Desert trees and shrubs: In an ideal world these should be on a separate irrigation valve but that may happen one out of every 20,000 homes. Examples include Palo Verde, Mesquite, Texas rangers, Texas ebony, cacti but usually not most succulents like aloe and the like. These plans can be irrigated less often than non-desert plants. The volume of water applied to them may be the same as above but more days between irrigations. During the summer they might be irrigated once every 7 to 10 days for instance. How many minutes for each station = valve. Somehow you have to translate minutes to a volume of water. Also, the volume of water delivered to each plant is dictated by the number and size (gallons per hour) of the drip emitters.  Here are some general guidelines. 1. Each plant should have a minimum of 2 drip emitters in case one of them fails. 2. Larger plants require more drip emitters. The smallest plants require two drip emitters. Medium-sized plants require four drip emitters. Larger plants/shrubs require 6 – 8 drip emitters. Trees may require 10 – 20 or more drip emitters depending on their size. If other plants are planted close to trees, under their canopy, the trees will require fewer drip emitters because trees are “drinking” from these other emitters. 3. Wet at least half of the area under the canopy of trees and shrubs. The number of minutes should be enough for water to penetrate at least 18 inches deep in the soil next to the emitters used for large trees and shrubs.  For small and medium shrubs, vines and groundcoveres, 12 inches is deep enough. Remember there are two types of overwatering: watering too often and watering using too many minutes. It is far worse to overwater the first way than the second.

Q. I planted this Red Push pistache in the fall and it has put out a lot of new growth this year. My concern is that the leaves are curling. Would you advise me on this? Red Push pistache planted and staked A.  Your tree looks very healthy and green. I would not worry about it much at all. A close look at the leaves shows there is some minor scorching along the edges of the leaves. Scorching on the leaf edges when the leaves are first coming out is enough to cause these leaves to begin to roll or curl as you call it. Leaf edges are damaged but the rest of the leaf continues to grow causing it to roll. Be careful not to water too often. It’s okay to water daily for the first week or 2 but after this you should not be watering daily. When this tree was planted the soil should’ve been thoroughly flushed with water.  Leaves cupping because the edges were damaged when young but undamaged center continued to expand If this has not been done, do it now by putting a hose with a sprinkler on the end of it with a very low volume of water coming out and flood that area under the tree for several hours. This helps flush any salts out of the soil in the area of the planting hole. When the tree was planted a hose should’ve been used to fill the hole as the roots of the tree was being backfilled with soil. A tree of this size might require at least 4 drip emitters located about 18 inches from the trunk. You must water the soil in the planted area. A tree this size might require 10 to 15 gallons each time you irrigate. Next year it might require 15 to 20 if it puts on some good size. Next year, add 2 more drip emitters if you are only using four now.

Q. Please settle a disagreement between my wife and me. Each spring my wife plants several plants in pots for our patio using bagged potting soil. Each year a few of them die and others live. This happened two years in a row. I contend the potting soils need to have some real dirt mixed in with it to make them better.   Most potting soils throw in some perlite for looks. The amount is too small to do much but it looks good! A. I hate to get in the middle of arguments between a husband and a wife. I think I can say diplomatically you are both right. Bags of potting or container soils are pretty much all the same when comparing those in the same price range. Commercial potting soil. No perlite but better than some of the bagged stuff.             You get what you pay for. Higher priced potting soils, like those from Fox Farm, use a higher percentage of more expensive ingredients. These potting soils cost more but they are superior compared to less expensive brands.             If you use inexpensive potting soil then add a high-quality compost to it. Add about 15 to 25% by volume. Adding your own compost helps inexpensive potting soils perform a lot better.