Xtremehorticulture

Xtremehorticulture of the Desert

Mushrooms Compared to Plants (Mushrooms ((Fungi)) are Considered “Plants”)

Leave a Comment / decomposers, mushrooms, Woodchips /

Q. The area where mushrooms grow best gets full sun all day. I had my almond tree removed. The roots were ground out, also a year ago. I think the mushrooms came with the dirty lawnmowers from the people that did my lawn last year. But two days ago, I poured straight vinegar on them. Yesterday they looked dead. But just to be safe, I bought some more cheap vinegar to pour over them if there are new mushrooms. I turned the lawn sprinkler off for 2 days so far. No more water! These were mushrooms after they lost their “caps”. Notice how mushrooms grow best with some food (woodchips), water (rain or irrigation) in contact with soil. A. Mixing soil with wood chips, together with water, is the perfect environment for mushrooms to grow during warm weather. Using a “stump grinder” and mixing those woodchips with the soil, in the presence of water, makes mushrooms. This is why mushrooms, in the presence of rotting wood, magically “appear” after a rain. The woodchips that are constantly being irrigated are gone. The wood has decomposed. The wood did amend the soil, but the small “chunks” of wood (woodchips) are gone. They were “dissolved” or decomposed. But not woodchips exposed to the rain! Those are in usually dry areas. Mushrooms (and the mycelia produced) are part of the decomposition process. Too bad some are disgusting or toxic and cause dogs that eat them to vomit. Mushroom are what we see after it rains. Just like flowering plants that flower after a rain, mushrooms “flower” after a rain as well. Except we see mushrooms. Underneath those “caps” are gill slits that release spores or seed. Some mycelia don’t produce mushrooms but many do. It can get quite complicated. The only things missing compared to plants is light (mushrooms grow best in darkness) and roots. Instead, mushrooms have “mycelia” (a “mycelial mat”, as its called, which spreads wherever mushrooms grow). Just like plants, the first to grow are the mycelia or “roots” of mushrooms. The mycelia are responsible from breaking down the “wood” and taking up nutrients. If there is enough water present (rain or increased humidity) then appear the mushrooms. Oftentimes mushrooms are not visible until after it rains but the mycelia (if there is some irrigation) are still responsible for getting the nutrients out of the woodchips. They are digesting wood even if we don’t see “mushrooms”. Mushrooms are just there for reproducing. My guess is that the mushrooms were not brought in by the mowers, perhaps the spawn (mushroom “seed” or mycelia) were but not the mushrooms themselves. Mushrooms are just evidence that sex was involved. Once established mushrooms (mycelia) continue to feed on decaying wood until the wood has decomposed and is gone. Their food is then gone. Some mycelia have a “waiting stage” and others die. But the soil is improved and becomes darker. Mushrooms are easy to kill. They last about two or three days when it’s warm. Next time use a rake and knock them down. Or let them have some fun! Save your vinegar, along with the seasonings, for pickling.  

Mushrooms Compared to Plants (Mushrooms ((Fungi)) are Considered “Plants”) Read More »

Fall Months a Good Time to Plant Tomatoes in Las Vegas?

Leave a Comment / indeterminate vs determinate, tomato /

Q. Is it time to plant tomatoes or still too warm? My garden is a raised bed on the south side of the house. We have a shade cover for the summer. Do I need it for the winter? Tomatoes seem to be the only vegetable I have luck with. Most squash are indeterminate as well like this one. Indeterminates just keep getting longer and longer. Indeterminates are used in greenhouses and large gardens. If you want to keep it flowering through the season, get the indeterminate form.  https://www.southernliving.com/early-girl-tomato-7550728 If you are growing in a raised bed, use predominately compact or determinate forms.  https://bonnieplants.com/products/bush-early-girl-tomato https://www.burpeehomegardens.com/Vegetables/PlantDetails.aspx?plantid=5093 https://www.edenbrothers.com/products/tomato-early-girl If you want to try a variety of the traditionally indeterminate type of  ‘Early Girl’ and still have it fruit early, then try the bush or determinate form of ‘Early Girl’. It was bred for small spaces like raised beds and containers. A. If you have an indeterminate variety (keeps getting longer and producing, such as the old-fashioned indeterminate type of ‘Early Girl’) you can cut it back now for fall production. In fact, it should have been cut back in September actually when temperatures are still hot but, looking at your app, first starts to cool. But try it now. Give it a shot. Alot depends on the weather after you cut it back. Sometimes you will luck out and it stays warm through most of the winter. The compact determinate types are pulled out after they produce fruit. Indeterminate types are cut back in the fall and then pray there is good weather. Judging from its green shape, I think it will be a grape tomato, not cherry. Tomatoes are tricky in this climate. Any time the temperature gets above about 95F tomatoes have trouble setting fruit. You will continue to harvest tomatoes that set earlier when temperatures were cooler, but tomatoes stop setting fruit when air temperatures are consistently above 95°F. Tomatoes probably produced well this past year if you kept fungal diseases at bay. This past year air temperatures would drop below 95°F erratically so tomato production may have been erratic as well in some parts of the valley. That’s what we want to accomplish is the perfect slicing tomato. This tomato was grown in Northern Afghanistan when I was there. Northern Afghanistan. although dry, had humidity more like the areas around Modesto, California. Always grow a couple of tried-and-true varieties such as the compact ‘Early Girl’, ‘Patio’, ‘Celebrity’, ‘Jet Star’ and others that you have had success with in the past. Always throw in a Roma type such as ‘San Marzano’ and cherry or grape tomatoes such as ‘Sweet 100’. If you are trying a couple of “new” varieties of tomatoes, do that carefully and remember what you planted. If you are serious about growing tomatoes, evaluate its production and care for it for three or four years in a row. You always want some older tried-and-true varieties as backups. Tomato suckers can be rooted in more humid climate or in a propagation house in the desert. Otherwise they are removed to improve air circulation through the plant. Planting in the spring Between February 15 and March 15 is better most years than cutting back indeterminate types in the fall. The weather can play havoc on gardens. You may luck out and have a non-freezing winter or location. Look at your weather app and which varieties of tomatoes you planted to determine the precise timing. When to plant, the varieties to plant and soil improvement are always important when growing tomatoes. Soils that have been “fluffed up” (rototilled or spaded) warm up faster than those that haven’t. If you’re using a soil thermometer, temperatures above 55°F are good for root growth on tomatoes.

Fall Months a Good Time to Plant Tomatoes in Las Vegas? Read More »

Agave with Black Spots on Leaves

Leave a Comment / agave, black leaves, disease /

Q. I cut out the leaves with the large black spots and lesions on my agave.  There are a few leaves with fairly small black dots speckling all over the underside (too many to cut out), should I cut off the entire leaf? Additionally, there is another photo showing the edge of the leaf that’s kind of perforated – is this age or some kind of bug/mite/disease? Agave with black spots A. I think this is a fungal disease that favors higher humidity than we normally have in the desert. The disease was caused and spread by the rain and wind that we had earlier. You don’t want that fungal disease spreading to the mainstem. To prevent that, you can apply a common landscape fungicide to the cactus if you think there is going to be a repeat of the rain and wind. Watch your weather app. If your weather app says the rain is returning, apply the landscape fungicide. In the meantime prune out any black spots that you see in the stems.  I would sanitize between any cuts to eliminate those black spots that you make. Use 70% ethyl alcohol to sanitize a knife or pruning shears. Both the fungicide during wet weather and cutting out the black spots will help eliminate problems.  Octopus agave originates in the Sonoran Desert of Mexico and Arizona. Make sure you’re not watering too often. Get it off of the irrigation controller and hand water with a hose. If you using a hose, water these plants five times a year; three or four times during the summer. Water with a hose three or four times each time you water these plants to get the water 12 to 18 inches deep as it gets bigger. Otherwise the water will only get three or 4 inches deep if you water them only once. Once you establish how often to water, don’t deviate from that except for the seasons. The number of minutes stays the same. How many times you water each month changes…that’s all. The leaves of agave won’t totally die back to the stem when part of their leaf is cut. It will just sit there, usually edged with brown where it has been cut. If it doesn’t look “funnier” and out of balance, I would suggest removing the leaves entirely. Your call. It is up to you if cutting the leaves of agave is acceptable or not. Some people don’t mind. Others do. Remember that fungicides prevent fungal diseases from getting worse. Right now, the humidity is above 15% so I don’t expect diseases to get any worse unless the plant is in poor health. I would recommend “dusting” the leaves with a fungicide dust to prevent the spread of those black spots that you are talking about. https://edis.ifas.ufl.edu/publication/PP154 Most fungicides are liquid now and not a dust. Dusts were more popular 50 years ago. If the fungicide exists as a spray, it is a different formulation from a dust. Read the directions. An alternative to dusts is to spray over the black spots as “insurance” to keep the disease from spreading if the weather or plant health changes. If it rains again, reapply the fungicide within 24 hours after it stops raining.

Agave with Black Spots on Leaves Read More »

Fruit Trees for Rocky Soil

Leave a Comment / fruit trees for the desert, rocky soil /

Q. Which fruit trees are best planted in rocky soil? The smaller amount of rich compost or soil is present, the more fertilizer fruit trees need. I fertilize fruit trees depending on the previous years growth. If the fruit tree grew abundantly during the previous year, I may skip a year of adding any fertilizer. If it grew adequately, then I know that’s how much fertilizer is needed. If it didnt grow very well, then I will put on a full compliment of fertilizer. Rocky soils dont have much soil so, once I found how much to give it I use that amount of fertilizer each year in the spring. A. As long as trees get the right amount of water and the right kind of fertilizers you can grow fruit trees in marbles!!! The more soil is present, the less often fruit trees are watered and fertilized. The more rocks means fertilizer needs to be applied more often. Granular, quick release fertilizers (many inexpensive fertilizers) should be applied about every 8 to 10 weeks. Slow release fertilizers are applied about every three months. Fruit trees that are tender to winter cold (they will freeze) should be finished with their fertilizer applications in time for cold weather. So if cold weather usually comes no later than mid December (the Las Vegas area is an example of this) then fertilizer applications should be finished by about August 1.          Rocky soil, to me, means soils low in organic content as well as full of rocks. In the desert, these soils may be growing fruit trees that are productive but can handle soils covered in rock on the surface of the soil better than some other fruit trees. I am guessing this definition could be extended into a prepared soil covered with a two to three inch layer of rock.             Stone fruit trees are like apricots, plums, and peaches; those trees that produce fruit that have a hard “pit” in the center. Stone fruit trees are among the best trees, in general, to grow in rocky soil because of their root’s tolerances to low soil organics, root structure and ability to suck up water from the soil at low levels of soil moisture. Fig trees can get large, over 40 feet tall, but they also can handle severe pruning to keep them smaller. We have done that over and over at the University orchard in North Las Vegas and have had no issues with it for 15 years! Remember to give them extra water, above and beyond what they need for their growth, if you want them to hang on to their fruit and be productive. Unlike their water needs for growth, they need more water to produce fruit during the hot summers. Olive trees a make it onto my list of recommended fruit trees to grow in rocky and low organic soils even though it is not used that much by some. Olives can be grown (outside Clark County) for fruit production. The fruit is either used as a condiment (green or black fruit) or the fruit is extracted for its oil (olive oil) or both. Citrus is probably the most often asked about fruit tree regarding soil organics. Yes, there are huge differences among citrus and their organic requirements. Most citrus are tropical to semitropical which include the true lemons, oranges, clementines and grapefruit. All four of these types of citrus do okay in rocky soils or grown under rocky surface mulch.

Fruit Trees for Rocky Soil Read More »

Will Argan Trees Survive in Las Vegas?

Leave a Comment / desert tree, plants from the desert /

Q. Can argan trees thrive in Las Vegas climate? I live in Summerlin and am thinking about planting a few because they provide a nice shade canopy. Would rats be attracted to eat the fruit? I don’t want to encourage a rat population. Argan tree (Sideroxylon spinosum) growing in Morocco on the fringe of the Sahara Desert.  Argan is a multi-purpose tree and each part of it is usable as a food or economic resource.  The fruit can be eaten, oil can be extracted from the nuts and the tree’s wood can be used for fuel. (Wikipedia). A. You have the right idea. The argan tree comes from the fringes of the Sahara Desert so potentially it could be used for lower amounts of applied water to a landscape. It has been reported to take the heat of the desert because of its deep roots. This is what tree gurus call a phreatophyte. Its water use is probably similar to other desert phreatophytic trees such as mesquites and palo verde, native to the Mojave and Sonoran Deserts respectively. Argon oil is popular right now. It’s pressed from the seeds of its fruit. Fruit from aragan tree https://www.feedipedia.org/node/54             This tree might be hard to find in the size you want. The tree is native to parts of Morocco, in the seasonally dry parts of sub-Saharan Africa. There has been some interest in propagating this tree for use in Africa. Research needs to be done before it’s available to the public elsewhere as trees. For instance, nothing is available on the best method of propagation to be used, the soil (microbiology), or selections preferred for landscapes.             Make sure that trees with a similar water use are on the same irrigation line. “Water lines” turn the water on and shut it off, all at the same time. The depth that water penetrates is dictated by the number of irrigation emitters used.             As far as attraction to rats, I would have to guess. Rats are omnivorous which means they will eat plants or animals. Like other animals they have food preferences and choices. My guess is that argon fruit might be low on their list of preferences. But if nothing is around for them to feed on, it should attract them.

Will Argan Trees Survive in Las Vegas? Read More »

Lawn Diseases Struggle When the Humidity is Higher than Normal

Leave a Comment / diseases, high humidity, lawn, rain /

Q. I live in Henderson where we enjoy having a lawn as part of our yard. It was thick and beautiful when we moved in, but it soon withered after we made some changes to sprinkler layouts and had the water off for awhile. I laid fresh sod and it too struggled. I tried a fungicide and that seemed to help but it then died completely.  Now the rest of the lawn is headed in the same direction. I’m at the point of desperation and could use some sound advice in the midst of some differing opinions. This is the lawn the reader talked about. It is dying in patches. The reader asked me to look at it (consult) but I think the disease problems we had (high humidity) earlier had a lot to do with it. A. Outside of watering, some lawns experienced disease problems earlier in the season that lingered after we had high humidity due to the rain. That change in our weather encouraged plant diseases to occur. In the desert, it’s usually the higher humidity that’s the problem. I will take a look at this lawn and see if the disease is advancing or has stayed put. That will tell me what his options are. Now he must stop the lawn disease (if advancing) and get the grass to come back. The humidity is now below 15% (except directly above lawns) and lawns should not need a fungicide application to keep the disease from spreading if we allow the lawn to dry after we apply water, and it is in good health. When there was higher humidity, some lawns along with some other plants, may have needed a fungicide. A lot of it had to do with the lawns current health. If you applied a lawn fungicide, it should have stopped needing the applications if the general humidity was above let’s say 25%. Plant disease susceptibility is sometimes compared to a three-legged stool. Plants are susceptible to fungal disease if: 1. the disease organism is present, 2. general health and susceptibility of the plant is good, and 3. the current weather. In this case, all diseases like moisture. A couple of months ago the weather (humidity) was the problem. The higher humidity is now over. The relative humidity is now in the “desert” range. I think you are seeing old lawn disease damage (unless the lawn grasses are in poor health). Make sure you follow label directions when you apply any fungicide. Any traditional broad-spectrum fungicide should work, but generally the higher-priced fungicides for lawns are usually a better choice in that respect. This fall we should be watering lawns about two to three times each week. No more than four times each week for sure! Water early in the morning (imperative) and wet the lawns from 8 to 10 inches deep in a single application when you water. Sloped areas, or hard soils, may need multiple starts, about 30 minutes to one hour apart, to keep the water from “puddling” into low spots.             Your lawn may not need it but try “aerifying” your lawn with a gasoline driven core aerifier. Then “topdress” your lawn with a rich compost to fill the aerification holes. Irrigate your lawn immediately after this. This process of filling the aerification holes, followed by topdressing and irrigation, improves the rooting depth of the grass. This will improve a lawns (grass) health.

Lawn Diseases Struggle When the Humidity is Higher than Normal Read More »

Planting Desert Spoon During the Heat

Leave a Comment / five gallon, heat, time of day /

Q. I purchased six each, 5-gallon sized desert spoons but I haven’t planted them since it’s been so hot. Should I plant them in the early morning when it’s about 90 degrees F? I have watered them three times a week. This desert spoon is in a container. The container is too small and it may not have enough soil or amended soil in it. Also it may need to be watered more often. Two headed desert spoon. The central growing point (bud) probably died and the plant suckered. A. It’s not the best time of year to plant them but yes, if you are going to plant them, plant them at a time during the day when it’s cooler and plant in wet soil. I think the major problem is the sunlight and not temperature. Never plant in a dry hole. In other words, make sure the hole has been filled with water the day before, or at least the soil is wet when it’s planted. If you elect to plant during the heat, plant as quickly as possible so the roots don’t dry out. Planting in a dry hole during the heat of the day is a common mistake made by contractors. The hole dug for this container was a bit larger than needed but you get the idea. University of Arizona recommends a planting hole three times wider than the container. So in your case three times the width of a 5 gallon container. How deep its dug is only important when the soil does not drain well. A hole filled with water should drain overnight.             The hole for planting should be dug three times the diameter of a 5-gallon container, even if it’s a “xeric” or desert plant. It’s not important to dig the hole deep unless it’s necessary. Every time you water, the water should wet all the roots to a depth of 12 to 18 inches. Root depth of plants is directly related to their height. Refer to https://wateruseitwisely.com/saving-water-outdoors/plant-watering-guide/

Planting Desert Spoon During the Heat Read More »

Growing Blueberries in the Desert

Leave a Comment / alkalinity, container, location, pH, soil /

Q. Can we grow blueberries here? How difficult is it? Yes, these blueberries were grown in Las Vegas. But at what cost? A. It is one of those questions that “we can but with what degree of difficulty?”. I am a lazy gardener and don’t like to put a lot of effort into “out of place” plants. I have a saying, the more out of place a plant is in its needs, the more time, money, and effort we have to put into it to get it to grow or produce. Take mangoes for instance. We can grow them here but what would be our “cost” of production? Yellowing of the plant leaves is just one of the hurdles that must be overcome when growing blueberries in the desert.             We know that blueberries prefer soils that are lower in pH (about 4.5) and don’t care much for the highly alkaline soils (closer to 8.0) of the desert. That’s a 1000 percent difference! Soil pH is our first hurdle to overcome. Are we willing to monitor the soil and amend it year after year? Use very fine ground (injectable) soil sulfur, not granular or “flowers” of sulfur for lowering the soil pH. I didnt get a picture of blueberries growing in a container per se but if you look closely you can see that this blueberry is growing in a container in Las Vegas. More than a curiosity? I wouldn’t go into commercial blueberry production in the Mojave Desert. Use containers so the soil is “contained” and easier to amend. Plants need good drainage. Use pine bark for good drainage and amend it with a very small amount of sand for stability. Blueberries have shallow roots so containers should be shallow; 10 inches deep. Place plants on the east side of a building so they get shade in the afternoon.  Southern highbush blueberries can tolerate the heat but not direct sun. Blueberries need at least 6 hours of full sun every day.             If you are willing to monitor and amend the soil annually (and grow blueberries as a cuiosity) then grow at least one of the Southern Highbush blueberries such as ‘Reveill’, ‘Sharpblue’, ‘Misty’, or ‘Southmoon’. Many of the Southern Highbush blueberries are self-fruitful but you may get larger berries and increased production if they can cross pollinate. But stay away from commercial production unless you do it (and is cost effective) in a greenhouse.             Apply fertilizer once every two months when they are growing to get good crops. The biggest hurdle to overcome when grown in our climate and soil is the soil pH.

Growing Blueberries in the Desert Read More »

Large Percentage of Pomegranate Fruit Comes from Older, Larger Wood

Leave a Comment / green, older wood, size, split pomegranate /

Q. I need some help.  I planted a pomegranate tree about three years ago. The tree looks great and there are always lots of fruit. The problem is that by the time the fruit gets up to about 2″ in size they are splitting open.  Can’t figure out the reason and I am yet to harvest a good pomegranate.  It gets full sunshine in summer and water 3-4 times a week. Any suggestions? A. Are the arils (pulp) sweet? Maybe it is ready to harvest.             First of all, the fruit should be larger than that. The fruit should get larger as it gets older and the tree is pruned correctly. A high percentage of small fruit is produced on smaller branches.  The number of large fruit is more as the tree gets larger. A higher percentage of larger fruit will come from the larger branches. That’s the reason for getting rid of the much smaller suckers. Get rid of the suckers at the bottom of the tree and force production on to about 5 or 6 main limbs that you keep. The best and larger fruit are produced on older wood. Small fruit are produced on young and smaller wood. I think the reason why some California growers prune toward only one large central trunk is that the fruit collected from it gets larger earlier.  Pomegranate pruned into a tree shape instead of a bush.             If the fruit is green when it splits, the same is true. The tree was not getting enough water as the fruit was getting larger. The fruit starts to become red, or red or white, or red and white when it starts into its last ripening phase. Yellow pomegranate brought to me in Tajikistan.             Fruit splitting is oftentimes a harvesting problem. Taste the seeds inside (called the arils) and see if they are sweet or ‘as expected”. There is a wide variation in flavor so don’t be surprised if the fruit taste is “puckery”. If the arils are sweet or “as expected”, it might be ready to harvest. Pomegranates are ready to harvest, depending on the variety, from September (‘Utah Sweet’) until early December (‘Wonderful’). The fruit should not crack unless they are past their harvest time. Young fruit still green and developing. It is several weeks away from harvest and sweet.             If the fruit are splitting before they are ready to harvest (not sweet yet but getting there) then it is a watering issue. Just like melons, as the rind sets up for harvest (sugars are accumulating) watering becomes critical. Watering when the rind gets hard (and it doesn’t need it) will split the fruit. w Pomegranate rind split and ready for harvest. Probably ‘Wonderful’.

Large Percentage of Pomegranate Fruit Comes from Older, Larger Wood Read More »

Mastic Tree Problems

Leave a Comment / growth, leaf change, mastic, newly planted, pistache, Pistachio /

Q. Can you tell from the attached pictures what might be happening to our mastic tree? Mastic tree. A. My guess is that the new growth is filling a “hole” made when the plant became a shrub. Mastic is a Mediterranean tree or shrub that grows slowly and naturally as a bush, to about 20 tall by 20 feet width. It requires, at the least, annual pruning when it is young to shape it into a single or multitrunked tree. It is best used as a background tree or shrub and not a smaller version of the larger Chinese pistache. It is not as pretty. It lacks fall color, tends to be shrubby, and smaller, but does have red ornamental nuts when they are young and before they ripen around August.             If this plant were mine and I wanted a small tree instead of being shrubby, as it tends to be, I would start to prune it in the winter or late fall months. Make a decision whether you want it as a single or multi trunk tree and make the appropriate cuts.  I would expose the trunk or trunks of this tree up to my knees by starting at the bottom of the tree. I would eliminate any growth below my knees and keep any upright growth. If I saw any suckers at the base, I would eliminate them. While it’s young, I would eliminate any growth growing downward or horizontal. I would concentrate most of my pruning efforts on keeping any upright growth to make it look like a tree and give it some height.             Water it like you would an olive tree. It is mesic in its water use. It will attract the leaf footed plant bug. Shearing this tree with hedge trimmer is a mistake. Fertilize this tree once or maybe twice lightly with a standard landscape fertilizer such as 16-16-16.

Mastic Tree Problems Read More »