Q. I screwed up in my pursuit of ant control with borax and sugar. It worked well but one evening last week I made the mistake of pouring my mixture right at the base of one of my vines rather than in a plastic bottle cap to keep it out of the soil. Now one of my vines is showing signs of toxic poisoning. I am very concerned about losing the other. I have added some 20-20-20 food hoping this will help recovery. Boron is an essential plant nutrient. Plants need it in very small amounts. Most soils have plenty in them. Borax contains about 11% boron by weight. Thats alot of boron when most plants are quite happy with soils containing 1-2 ppm boron. Thats ppm or parts per million. As a salt, boron is transported to plant leaves where it accumulates along the edges of leaves where water goes into the air, thus concentrating it. A. Ouch. What you are seeing is most likely boron toxicity. Boron is one of the 16 or 17 essential nutrients for plants, but it is needed in extremely small amounts. But if that very small amount is too much, it becomes toxic to plants. The difference between enough and too much is in the parts per million range! Grasses are a little more tolerant of higher amounts boron than other plants.             Boron does not move in the soil very well like other contaminants. That might prove to be in your favor. Remove the surface soil around the plants down to about 4 to 6 inches and get rid of it. Hopefully you removed some boron mixed in the soil as well.             Organics in the soil help to tie boron up and make it less available to plants. Put a fresh soil mix back with 50% compost mixed in it.             Water dilutes salts including boron. Water the heck out of the areas where you applied borax to try and dilute the boron remaining in the soil and push it below the roots. Water, then let it drain, water, then let it drain. Do this four or five times to push salts containing high levels of boron below plant roots. Lastly, pray.

Q. I have a 17 ft. x 2-1/2 ft. raised bed on the south side of my home I would like to turn into an all-season cutting garden.  I will probably use a portion for growing herbs for cooking. I plan to plant flowering bulbs for Spring flowers.  I would like to have other perennials planted above the bulbs to fill in as the seasons progress.  I am open to planting annuals if they can be used for cut flowers for bouquets. What flowering plants would you recommend?  A. Whoa! You must be a very good desert gardener to pull this off! If you are thinking of the pictures in Sunset Magazine and its easy, it’s not. Lots of soil modification, correct planting time of year, differences in exposure to sunlight, wind, shade, plant selection will all be important.             I strongly recommend joining one of the garden clubs in town such as the Chrysanthemum Society or Iris Society and start absorbing information and ask questions. Google the Nevada Garden Clubs, Inc. website and send in a request. A mentor of mine when I first arrived in the desert was a former president of these clubs and she was a great gardener.             Lots of plants can be grown for cut flowers in the Mojave Desert. They favor different exposures to sun, shade, wind, and planting times. Whenever considering cut flowers it requires wind protection, or they will look ratty. Some are bulbs. Some are started from seed and rhizomes. The most successful growers of flowers I know, plant in different locations in the landscape to take advantage of different “microclimates”.              So, if you have not yet developed your desert “green thumb” then start with a small area and experiment before thinking big.  Some spring bulbs to consider include dahlia, canna, gladiolus, and amaryllis. Fall bulbs might include crocus, narcissus, hyacinth, ranunculus, and even tulips if you prechill them in the fridge first or buy pre-chilled bulbs. Consider iris and all types of mums. There are garden clubs in southern Nevada that focus on these plants. Contact Las Vegas Mum Society Contact Las Vegas Iris Society             Many other perennials grow here as well, too many to list, but require different exposures to sun, time of year and wind to perform best as well as soil enhancement and irrigation. Two of the toughest to grow are begonias and calla lilies.  Many thanks to a mentor of mine, Hobby St. Denis, a terrific desert gardener and former President of the Associated ! Much of this information is contained in the book she wrote for the Nevada Garden Clubs, Inc. and no longer in print. And also a publication from the University of Arizona.

Q. I need to block out my neighbor’s intense landscape lighting that pierces my screen of photinia and comes into my yard. I plan to attach Mexican palm thatch to the iron fencing behind the photinia. That extra layer will block my neighbors landscape “headlights”. Should I spray the palm thatch with any insecticide first in the event there are bugs that could invade the photinia? A. It sounds like an inexpensive way to enhance the enjoyment of your backyard at night. Those fronds should last about 2 years before they need replacement. They will last longer with fewer holes created in the fronds when attaching them to the fence. Some box stores offer reed fencing that might save you some work, last longer and is ready for attachment.             I know of no bugs that would be a problem spreading to your photinia from the fronds so no need to spray. I also don’t foresee any future problems using palm fronds except a potential fire problem if they were to ever catch fire. An inexpensive fire retardant is to spray them with a solution of ammonium sulfate dissolved in water.

Q. I just planted a 5-gallon mesquite tree following your advice and was wondering how I should stake it. Also, I was wondering if I should use the deep watering stakes recommended for it? They are plastic, two feet long with holes drilled in it for deep watering and supposed to encourage deep rooting of trees. A. If the planting hole is dug wide enough, the soil used when planting is amended with something decent, then these deep watering tubes are not necessary. If you water your tree deeply, and not daily, the tree does not need them. If you water your whole yard daily including your trees, which I don’t recommend, then maybe there is some benefit using them.  Buy Soil Aeration Tubes?  The problem with digging a planting hole deep when its not needed is making soft soil beneath the tree that may cause it to sink as the soil beneath it collapses and trying to drive a sturdy stake into soft soil and expecting the stake not to move, along with tree roots.             I have not listened to the sales pitch for these deep watering tubes, but I would guess they are marketed to prevent shallow roots from growing on the soil surface. Most trees don’t want their roots on the soil surface. They want their roots to grow deeply for better anchorage in the soil and access to a larger amount of water.  The Problem is Soil Aeration Tree roots need access air as well as water. Roots need to “breathe”. Watering so often that deeper soils stay wet or the deeper soil is very compacted will hinder air from getting deep in the soil. True of clay soils, wet soils and compacted soils. Small trees should have soil amended to a depth of 18 inches, medium height trees to a depth of 24 inches and tall trees, like most of our pines, to 36 inches. Not all Roots are the Same Root depth of trees is controlled by three factors; if tree roots normally grow shallow (its genetics which is mostly the soil environment where it is from), condition and type of soil and how the tree is watered.  These watering tubes focus only on the third factor.  Control root depth with soil amendments and water management . Trees and large shrubs should be watered separately from shallow rooted plants like lawns, flowers and vegetables. This gives these larger plants a chance at growing roots deeply.             Some trees like mulberry and many types of ash have a preponderance of shallow roots. Its normal for them. It is part of their genetics and the environment where they came from. They like floodplains and wet soils. That’s why they do so well in lawns. In some cases, these roots can be removed from the soil surface or covered with mulch.             Some trees grow roots near the surface of the soil where roots can access air better. This happens in heavy clay soils or soils where the planting holes were not dug or prepared well. With heavy clay soils it is best to grow trees on a 12 to 18-inch rise or mound, so the soil can drain, roots can “breathe” and have somewhere to grow. Advice on Digging Planting Holes             I have harped on planting holes ad nauseum, but always dig the planting hole at least three times the size of its container and amend this soil with decent compost at the time of planting. Buy these tubes only if needed.             If the tree is from a 5-gallon container, then it may not need staking. Trees planted from larger containers probably need it. The primary purpose of staking is to keep the roots from moving. Movement of the upper trunk and limbs is a good thing.

 Know which rose varieties have been successful in our hot desert climate and how to plant and manage them correctly.  Attend the annual Rose Show on the afternoon of November 9th at the University of Nevada Cooperative Extension offices just south of the airport on the corner of Windmill and Paradise Rd.  Rosarians will be present to answer your questions about growing roses in our hot desert climate and poor soils from 1 to 4 pm. For more information call the Master Gardener Help Line at 702-257-5555.

Q. We have a mature pear tree standing about 14′ tall that produces about 100 pears each year. These pears are always rock hard when harvested regardless of how long we leave them on the tree. We have attempted ripening them indoors, in brown bags, all to no avail. A. Do you know what kind of pear it is? There are two groups of pears; the European and Asian pears. The Asian pears are normally round or roundish and crunchy, much like a crisp apple. They are not rock hard, but they aren’t soft, either. They are “crunchy” in texture. Most people are familiar with Bartlett pear, a European dessert pear that is picked hard but ripens and softens after harvest. All pears pictured were grown by me in the Mojave Desert.             Most of the European pears are dessert pears, but a few are cooking pears. The dessert pears will soften after harvesting but the cooking pears do not. They stay firm, some might say “rock hard” when compared to dessert pear like a fully ripe Bartlett. Some of the European pears used fresh (aka dessert pear) are Bartlett, Comice, d’Anjou, Bosc and Seckel. The stores in the US carry a lot of Bartlett but there are some excellent other dessert pears out there to try. Comice pear, a European dessert pear, also does well in the Mojave Desert.             Most dessert pears are picked when still hard but after the background color of the fruit has begun to lighten. This is true of Bartlett because its flesh will have a “buttery” texture when picked before they are fully mature and allowed to ripen at room temperature for three or four days. Sensation Red Bartlett, another dessert pear, also does well here.             I’m thinking yours is a European type cooking pear. A popular variety is Kieffer. They don’t soften much at all when ripe because they are used for cooking and making pear sauce, compote, jams, jellies, pickling and used in stuffing.  Kieffer pear is a European pear but it is a cooking pear. They are called cooking pears because their flesh stays firm after cooking. They can be left on the tree longer because they stay very firm when ripe. If I am right, there is nothing you can do to soften them and you either enjoy them for their cooking attributes or replace the tree.

Q. This tree in my front yard is turning yellow. It is 20 years old. Is it because of lack of water? Should I have it trimmed? This is the canary island date palm talked about. Notice the lower fronds scorching on the edges and turning yellow. Water could be an issue. A. Lack of water can have two meanings.  Not enough water applied or not watered often enough. Sometimes it can be both…too little water applied and the water that is applied is not applied often enough.  Hard to judge but my guess is that water may be part of the problem. When water is applied to palms, a lot should be applied all at once and then hold off on the next watering for about the same time as other nondesert trees, like fruit trees, need water. For date palms in Las Vegas this is about one week, maybe twice a week at the most in the middle of summer.   See that cluster of new growth going straight up in the center top? Good sign. It had enough water to push spring growth. But what about summer growth? The browning on leaves seen in your pictures is on older leaves at the bottom. That is normal for it to happen that way. It is NOT normal if leaf fronds are turning brown along the edges on newer fronds higher up.  The palm to the right is getting water. The palm on the left is not. Look at the grass at the base. Palm Drought Water should be applied to a distance of about three to four feet from the trunk all around the tree. In many soils about two inches of water in the basin around the tree is enough to get it down to about 24 inches. This would be about 50 gallons. So the palm tree roots have to have access to about 50 gallons of water at least once a week to 100 gallons if it is watered twice a week in summer. But the important part is giving the soil a chance to drain and start to dry out after an irrigation. This is date palm, not canary island date palm, but the roots will be similar. This date palm was removed from the farm, harvested, so the roots are cut. It is pushing new growth from the center so that tells me If underwatering is severe the fronds will be smaller and scorched. From the picture   Palms pruned with enough canopy remaining to provide some protection to the central bud. As far as pruning, remove the lower fronds so that the remaining fronds are in a half circle

Q. I know Roma tomato plants are determinate in their growth but if I keep them healthy will they set a fall crop for me? A. All I can tell you is what I think will happen if it is a determinate tomato and how to prune it for fall production. There are a lot of unknowns involved but this should give you the best chance. Roma Confusion             Roma tomatoes are a certain type of tomato good for making tomato paste because they dont have a lot of water inside the fruit. So sometimes Romas are mixed with paste tomatoes and plum tomatoes and called paste types. Yes, Roma is determinate but paste types are predominantly indeterminate. So check what you got. Determinate Vs Indeterminate Determinate tomatoes are plants that are bush-like and produce fruit over a short time so it’s easier to pick. Indeterminate tomato plants grow as tomato “vines” and produce fruit spread out along these vines over a longer time. So-called Roma tomatoes are considered paste or plum tomatoes and many of these types can be either determinate or indeterminate. It’s good to know which you are buying for proper spacing and management. Fall Pruning             All plants need new growth to set flowers and fruit. For Fall production we want to stimulate new growth when air temperatures are entering the mid 90s. While indeterminate tomatoes can be cut back a lot in the Fall because they are so long, determinate types are cut back less due to their smaller plant size. Prune the plant back enough to provide for new growth but not enough to open the plant canopy for sunburn. Follow this pruning with water and fertilizer.

Q. I had my yard re-landscaped in June and with it I planted a Desert Museum Palo Verde. After planting, I pruned it and maybe removed too much which caused some sun damage. My great aunt used a lime and water “paint” on her trees to repel critters and I’m wondering if this might help. A. The time of year it was planted probably had something to do with the damage you’re seeing. The lime and water paint was used in the past mostly to reduce sunburn from intense sunlight. The reduced damage from painting the trunk and limbs attracted fewer insect problems. Fruit trees with trunks painted in Afghanistan. This was probably done by someone from an NGO and not done by locals for insect  and sunburn control in Balkh Province. lime and water concoction             But painting trees with this concoction was also used to make them look prettier. It’s still done for ornamental purposes in some countries. Now we paint the trunk and larger limbs of fruit trees with dilute white latex paint mostly to reduce damage from boring insects attracted by injury from intense sunlight. That’s its primary purpose. Plant at the Right Time of Year             First off, planting trees and shrubs in the spring or fall months leads to more success and less damage than planting during the summer months. Palo Verde, like most landscape plants, should be planted in late January or February or late September and October for best success. Those spring and fall months are more forgiving than planting during the heat of the summer. Transplant Shock             Secondly transplant shock, or the “interruption in growth” of plants when moved from a container into the landscape, is more dramatic during the heat of the summer than during the cool spring and fall months. Transplant shock that time of year varies from almost nonexistent to severe branch dieback depending on the care given when planted. Dig the hole and planting depth             Dig the planting hole three times the diameter of the container and make sure plants go into a wet planting hole as quickly and carefully as possible. Never plant into a dry hole even if you add water immediately after planting. Damage from planting that time of year during the summer in coastal California might be minor but not in the Mojave Desert.             Make sure plants are planted at container depth and, after planting, have not sunk deeply into soft, wet soil. This can be difficult to detect after planting and is a major cause for plants that struggle and eventually die after planting. Water Deep and Not Often             Water this tree under the canopy with enough water to wet roots 24 inches deep. Irrigate again to keep the soil moist at this depth, but not wet. Irrigating frequently and deep enough to keep soils moist will cause your tree to stay full, grow quickly and recover from sun damage. When it gets larger, reduce how often the tree is watered but not the volume of water applied.

Q. There are lots of black seeds when you cut open a papaya fruit. Can the green sprouts from these seeds be eaten and added to a salad? I don’t want to grow a tall papaya tree in my condo. A. Since the fruit produced by this tree is not important to you, the seeds can be collected, germinated and used for “sprouts”. Not many people are using these seeds for sprouting because the white latex sap of many plants is oftentimes a warning sign parts of it may be poisonous. Im on our farm in the Philippines now so I went out and nicked this young papaya with my fingernail so you could see the latex             Papaya sap contains a white latex thought to be important in reducing its pest problems. This sap however is used in pharmaceuticals and meat tenderizers because it contains an enzyme called papain.  The same papain is used to speed up skin and muscle repair from sports injuries like cuts and abrasions, “leaky gut” syndrome, and implicated as useful in treatment of shingles, hay fever and minor aches and pains. Not much is known about eating papaya sprouts. Much more is known about the papain derived from the fruit or leaves. Its also known in local folklore to reduce sex drive. Maybe that’s why its nicknamed the fruit of priests. Back in 1993 when I first went to the Philippines the locals in small villages on Palawan were pleased to see me eat alot of it and I didn’t know why. I was single at the time. Papain enzyme