Xtremehorticulture

Xtremehorticulture of the Desert

Grubs in Container of Garden Soil Killing Plants

1 Comment / bugs in compost, compost grubs, june beetle, masked chafer, white grubs /

Grubs found in our compost piles Q. I have discovered over 200 huge grubs in a 15 x 24 inch container that is about 2 ft deep. I had filled this container with a bag of garden soil from a garden center and planted strawberry plants. Of course the plants all died, so I decided to plant some seeds and discovered all these horrible grubs!!! I have been told that a product called Grub-Away is safe to use and that nematodes are even safer. But my main concern is all the earthworms that are in my gardens. I put in the worms last year and am seeing tons of babies. I really do not want to harm them. So far, I have been digging up sections (all raised beds) and destroying the grubs. If the grubs were in the bags of soil I bought, do I need to treat future purchases? A. Most of the grub control information is focused on lawns. However there are other grub problems such as those you find in the compost and even bagged compost. In most of the United States the problems in compost are considered minor compared to lawns. White grubs feeding on the roots of a lawn grass, killing it Here in our desert Southwest where we have fewer lawns the importance of grub control in compost piles and even bagged compost is usually just or even more important than lawns. The nonchemical control of the white grubs in lawns will also work for the most part in compost or bagged compost. Technically, to be legal the recommendation or control should include the site of application. I have to give you that warning to be in compliance with the law. Adults of one of the compost grubs, masked chafer For instance if the product is being sold for pest control in lawns, then it should also include your application on the label. If you choose to use it for this purpose you are doing it at your own risk of success or failure. Having given you the Party line, those pest-control products that are biological or natural should be perfectly safe to use. There are some very expensive bagged composts that are actually very good but those producers believe in NOT sterilizing the compost. And this is a great idea in theory. The reasoning is that they want all of that biological activity added to a garden soil. You go through the expense of quality composting that produces all of this wonderful biological activity for the soil and then you kill it. Another adult form of compost grub, green june beetle This biological activity contributes to the breakdown of organic material in the compost and releasing plant nutrients and a wonderful chemical activity that can take years to develop into normal Desert soil. Many organic growers would be dumbfounded in the logic of killing biological activity in compost. This biological activity is precisely one of the reasons why you compost. On the other hand, not sterilizing a bag of compost will introduce all of this biological activity to whatever you add this compost to. So if you buy a bag of compost that has not been sterilized and you use it with your houseplants there is going to be a very good chance your houseplants will be infested with dusky winged fungus gnats for example. I get many questions submitted to me on how to control this pest in houseplants. This is seldom a problem outside in the garden in our climate. Another adult of a grub, ten-lined june beetle So you have to be careful which type of compost you use for which application. In my opinion I would never use an unsterilized compost for houseplants for precisely this reason. Inside the house or greenhouse all of your products should be sterilized if you don’t want these problems. These are closed environmental systems and must be managed as such. You must scrutinize everything you bring into a closed environmental system because there are few checks and balances to help keep introduced pests under control. I like these newer bagged composts very much and there is a developing market for them primarily due to the development of local markets for food. They are expensive, running $20 per bag or more. One product line that is popular right now is Fox Farm products. If they can keep their quality control as the demand for products like this climb, it will be a good product but check the bag and see if it was sterilized or not. Worm for composting If not and you want it sterilized then put the bags in full sun during the summer months for four days and flip the bags over every day. This should heat sterilize the contents provided the temperatures reach 160F for at least 30 minutes. That should be no problem in our environment but if you want to make sure then buy an inexpensive compost thermometer online (I have not seen any available in Las Vegas) and stick it in the compost bag, burying the probe to the hilt. In mid-day you want the temperature to hit at least 160F. Secondly, you should inspect any compost and get rid of any grubs. These are decomposers and are working at helping to decompose plant materials but are first level decomposers and will attack the roots of healthy plants as well. So screen your bagged compost before using it if you want to maintain its biological activity. There are natural pest control products for grubs such as beneficial nematodes and bacteria like Milky Spore but they will focus on some grubs and may not others. They are somewhat selective and may be a good alternative treatment that will leave earthworms alone. Remember that earthworms can move pretty fast. If they don’t like an environment they usually flee. Grubs have a harder time doing this. But the earthworms must be able to flee somewhere and if they

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Constructing Raised Beds With and Without Side Walls

Leave a Comment / construction, desert soils, instructions, raised beds /

Q. Hello Professor Morris, I’m trying to figure out how to just post questions in the blog,  so you won’t have to reply separately (if the answer is in the newsletter I’ll just see it there).  I wonder if there is a best size or height for a raised bed.  I want to put in enough good soil, but don’t want to make it higher if I can make it larger, to grow more plants using the same amount of soil.  Trenching desert soil for creating rasied bed A. The height is up to you  and what your back can handle. For root crops and asparagus they should be a minimum of 18 inches deep. Most desert soils can grow excellent vegetables and flowers if they are amended properly at the very beginning. You can use existing desert soils at the location of the bed or you can import manufactured soils from sand and gravel companies or nurseries. If you import a manufactured soil, do not use reject sand. If you are importing a soil to use in place of your soil at the site, select a manufactured soil that resembles the soil at the site as closely as possible. Take a sample of the soil at your site when you are selecting the imported soil so you can compare the two. Check it to match the texture (how sandy or clayey it is) so the garden bed will drain water into the existing soil. Problems with drainage can occur if the two soils, the soil at the site and your imported soil, are dramatically different from each other. Adding compost before tilling and forming the raised bed Raised garden beds should be oriented north to south if at all possible. Their dimensions should be 3 to 4 feet wide if you can access the bed from either side. If the bed is accessible from only one side then perhaps 3 feet would be the maximum width. Keep garden beds at least 3 feet from foundations and block walls if at all possible. Once established, you should avoid walking on the raised garden beds other than for possibly planting or harvesting. Use kneeling boards. Never walk on them wet. I would recommend drip irrigation and using tubing with built in in-line drip emitters. I would use the larger drip tubing such as half-inch and not the smaller laser tubing. Visit with Timmy who runs irrigation department at the Plant World Nursery on Charleston. He will set you up with a drip irrigation system and components that you can run off of a hose bib or garden hose if you want to. These steps will create multiple raised beds at the site without constructing sidewalls by using and amending the existing soil. 1.         Rip the soil to a depth of 12 to 18 inches with multiple trenches over the entire site. I usually use a trencher. 2.         Remove large rocks. 3.         Flood the trenches with water as best as you can. 4.         Fill trenches with compost. 5.         Collapse the sides of the trenches Finished, planted and labeled raised vegetable bed made from raw desert soil and compost. 6.         Apply 3 to 4 inches of compost to the entire site and rototill as deep as possible. 7.         Remove rocks larger than a golf ball. 8.         Create pathways that are 18 to 24 inches wide between the raised beds by shoveling the amended soil onto the raised beds. 9.         Shape the beds using a landscape rake and garden rakes so that it is a level and the sides of the beds are at a 45° angle. The cross section of the width of the bed should resemble a long trapezoid. 10.       Firm the bed using a roller so that your footprints sink no more than 1/2 inch into the soil when you walk on it. 11.       Install irrigation. 12.       Your bed is ready for planting. 13.       Every time you plant, incorporate a 2 to 3 inch layer of compost subsequently for the next two years. After two years you can reduce the amount of incorporated compost to 1 inch. These steps will create a raised bed using constructed sidewalls. 1.         Rip or at least disturb the soil to a minimum of 6 inches beneath the raised bed. 2.         Construct the sidewalls with your choice of building materials and to your desired height. For root vegetables and asparagus the depth should be a minimum of 18 inches. 3.         Line the inside of the constructed sidewalls, not the bottom, with heavy gauge pond liner. 4.         If you’re using a manufactured soil that has not been amended with compost: •        Mix good quality compost with your desired soil outside of the raised bed in a volume ratio of three parts compost to one part soil (3:1). •        Remove any rocks larger than a golf ball. If you are planning on a lot of root crops then screen the soil so that any remaining rocks are less than 1/2 inch. 5.         If you’re using a manufactured soil already amended with compost: •        Mix good quality compost with your desired soil outside of the raised bed in a volume ratio of one to two parts compost to one part soil (1 or 2:1) depending on the manufactured soil color. If the manufactured soil color is predominantly gray or tan, then use 2:1. If the manufactured soil color is light brown, then use 1:1. •        Remove or screen any rocks in the soil. 6.         Fill the raised bed with the amended soil and settle the soil with water as you are filling it. Fill the raised bed so that the soil is 2 inches below the top of the raised bed. 7.         Make sure the raised bed is firm and not fluffy. 8.         Install your irrigation system.

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Modesto Ash Landscape Tree Usually Does Not Establish a Tap Root

Leave a Comment / ash tree growth, irrigation, shallow roots, surface roots /

Q. I have a Modesto ash tree in my front yard.  I have had it for 12 years, so it is a big tree.  I am having a problem with its roots.  They are coming up through the grass.  Are those top roots?  They are ruining my yard.  What can I do for this problem?  I love the tree but not the roots. Surface roots of large tree. My picture, not the readers. A. This can be a problem with ash tree particularly if they are not watered deeply and were planted in a lawn. Lawns are typically watered with shallow irrigations because most lawn roots grow in the top 12 inches of soil. Since the tree is also growing in the lawn and receiving the same irrigation water as the lawn they will be in competition with each other for this water.             Maybe you mean tap roots and not top roots? Tap roots by definition do not grow on the surface of the soil. Trees with tap roots in nature seldom develop true tap roots once they have been replanted or transplanted into landscapes.             To develop tap roots trees need deep waterings or have deeper water available to them for their roots to grow into. In our desert environment most irrigations are shallow since water is expensive and we try to conserve as much as we can. In some cases you can remove a few surface roots without compromising the tree. You could explore this option.             Trees use their roots for taking up water and nutrients as well as stabilizing itself in the soil to keep it from blowing over. Tree canopies act like sails. If too many roots are removed, obviously this could result in the tree blowing over in heavy winds.             If you are removing more than one or two roots then you should consult with a certified arborist about the potential for blowover.

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Watering Santa Rosa Plum in the Mojave Desert

Leave a Comment / drip irrigation, fruit trees, how many gallons, irrigation /

Q. I read your gardening articles faithfully, and I just searched your blog for some help, but I would like more information.  I just purchased a Santa Rosa plum, but I am not certain how much I should water it.  I haven’t yet planted it, and I want to make sure to give it enough emitters as it is located in the front yard which is mainly desert landscape plants and therefore do not require as much water as this will (I think).  Santa Rosa plum The tag indicated how much water in inches, and I wasn’t certain how to convert that into gallons.  Also, although there is rock mulch in the front yard, I am more than happy to remove that in this are to give the plum the best chance.  Is that necessary?  Finally, your article on planting fruit trees from your blog mentions a “slurry” but I don’t know what that means, and I wasn’t able to find a definition on your blog.  I would really appreciate some help.  Thank you.  A. Plums are not desert plants and should not be irrigated as if they were desert plants. Mixing desert plants with non-desert plants on the same valve can lead to watering desert plants to frequently or, the flip side, watering the non-desert plants not often enough. But this may be a moot point. In this town desert landscaping means surrounding any type of plant with rocks. This is kind of like calling tofu, meat. Just because people put rocks around plants does not make it desert landscaping but does give it the appearance of desert landscaping. Hopefully your Santa Rosa plum will be on a valve that has other drip emitters on it. The first thing to do is determine your current run time for that valve on your irrigation clock; the number of minutes or hours that station or valve operates. It will be more difficult to irrigate your plum if the valve irrigates other things on it that are not on drip. Drip irrigation is designed to give small amounts of water over long periods of time, usually hours. Other types of irrigation such as bubblers or sprinklers are designed to operate in minutes, not hours. Mixing the two together on one the valve makes it very difficult to accurately apply water to either one. I like to see true drip irrigation operate a minimum of one hour. Let’s assume that the valve for your plum will operate for one hour. (Now I am going to give you some misinformation and tell you a couple of lies so that I can make my point. I will clear up the lies and misinformation later.) So, if the plum was purchased in a 5 gallon container, then make sure it gets irrigated with 5 gallons of water in that one hour. If it was purchased in a 15 gallon container, then give it 15 gallons in one hour. As a tree in a 5 gallon container gets bigger, you will need to increase the amount of water applied to it in one hour to perhaps 10 gallons or 15 gallons next year. You can do this by adding additional emitters; perhaps a second one next year and the third one maybe three years from now. If the plum is really growing fast you may have to add emitters sooner. This is a judgment call. Mature plums at the Orchard are getting 30 gallons every time they are irrigated. This 30 gallons is applied once every 10 days to two weeks during the winter to as frequently as twice a week in midsummer. As it gets hotter, the frequency of applied water changes, not the amount per application. Let’s say you now have discovered a problem. The valve which will irrigate your plum runs for 15 minutes, not one hour. And everything on that valve is designed to be irrigated in 15 minutes. This means we have to enter the dark side of irrigation; bastardizing drip irrigation to get it to do something it was never intended to do. Adjustable drip emitter: the dark side of drip irrigation. Now we enter the realm of adjustable drip irrigation emitters. These emitters can be adjusted with flow rates of zero (shut off) to a lot. Oh, they like to say it is 0 to 10 gallons per minute but in actuality who really knows? I don’t care what they call it but this is no longer drip irrigation. But in some cases it will get the job done and you may have no other choice. Plants surrounded by rock mulch use more water than plants surrounded by wood mulch. Any type of mulch will help but rock mulch will get hotter than wood mulch and drive water use up. Some plants should never be planted in rock mulch. Your plum is one of them. Others include roses, lilies, Photinia, mock orange, heavenly bamboo and many others. It might be okay for a couple of years but I will guarantee its health will decline living in rock mulch after just a few years. Organic mulches like wood mulch will help your tree a lot. This wood mulch should cover an area not less than 6 feet in diameter around the plum tree and be at least 4 inches deep. Be sure to keep wood mulch a foot away from the tree trunk the first four or five years. There is 7 1/2 gallons in one cubic foot of water. 1 inch of water covering one square foot is a little bit more than half a gallon, actually 6/10 of a gallon. Since rain is measured in inches of precipitation and sprinklers are also measured in inches of precipitation per hour there is a tendency to give watering advice in inches rather than gallons. They leave it up to you to determine how many square feet you are going to irrigate. A penstemon might be irrigated over an area of

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July todo: change out the pheremone traps and pheremones

Leave a Comment / codling moth, control of, peach twig borer, trapping, wormy apples, wormy peaches /

Pheremone sticky trap (sticky part is removable on the bottom) with an orange rubber thing that is impregnated with the synthetic pheremone. These must be changed regularly. Change pheremone sticky traps and replace the pheromones. Are you plagued by wormy apples, wormy pears, wormy peaches or nectarines, or wormy apricots? You may have codling moth in appes and pears and peach twig borer in your stone fruits.         Pheremone traps are sticky traps that attract specific problem insects through releasing of sex hormones produced in a laboratory to mimic the opposite sex and then trapping them with a sticky surface that can be replaced.         To control these insects you will most likely need to spray pesticide. Don’t be too alarmed because the pesticides you can use are listed for organic production. The most common ones used include Bt (Bacillus thuriengensis; aka Dipel or Thuricide).         The other chemical you can use is Spinosad. Spinosad is rougher on beneficial insects that Bt. You would spray just a couple of days when you get LOTS of these insects (the adults of these insects are small moths about 1/2 inch long. The larva or immature is the worm that gets into the fruit.

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July todo: harvest onions

Leave a Comment / stepping on the tops, when to harvest onions /

Walla walla grown at The Orchard in North Las Vegas. Both northern and southern onions can be grown here well. Check onions. Onions do remarkably well in our climate. They like to have soil that is well drained, free from large rocks and relatively sandy. Transplants are normally planted around March 15 year. If you decide to start onions from seed and grow your own transplants, you would do this about the same time you plant garlic; late September and October.           Onions are heavy feeders of fertilizer particularly nitrogen. They do well if you put phosphorus in the soil prior to planting. I like to feed onions with nitrogen lightly, monthly, during their active growing time. It is not so important when the temperatures are cold and they are not growing fast. Wait for the tops of onions to fall over before you harvest unless you want to eat them fresh and not for storage           Wait for onion tops to fall over before you harvest them. I do not recommend that you step on the tops to break the necks. They will do this all on their own and you do run the chance of developing rots if you store them for any period of time.           So at this time of year begin to watch for onion tops that fall over. Once they fall over you can harvest the bulbs and trim the tops. You can also leave them in the soil for a week or two and harvest them fresh if you want to. Once the tops have died completely, I would get them out of the ground.

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July todo: harvest herbs gently

Leave a Comment / eating basil, edible flowers, harvest herbs /

Harvest herbs. Lemon basil in bloom growing at The Orchard. Sometimes the flowers are used as garnishes, cooking, arrangements, salads and all sorts of things. •        The four most damaging conditions which impact fresh herbs and “soft vegetables” is damage from handling, heat, low humidity, and direct sunlight after harvest.  The smaller and more delicate, the more damage. •        Harvest in the early morning hours when temperatures are cool, humidity is higher and there is little or no wind. The volatile oils and flavors will be at their best this time of day. •        Herbs and soft vegetables should be cut with a sharp, sterile knife or shears and lifted not pulled.  It is best to have cool water in a clean pail with you in the field so that herbs and soft vegetables can be immersed immediately upon harvest. •        To clean fresh herbs, submerge them in a sink or large bowl (depending on the quantity of herbs) filled with cool salted water (about 2 tablespoons salt per sinkful). The salt water will drive away any insects without damaging the plant itself. Remove the herbs from the standing water, and dry in a salad spinner. To dry herbs completely, blot with paper towels. •        The ideal time of season to harvest most herbs is just when the flower buds are forming, but before they open. •        Gently wash herbs and vegetables down with a spray of water the night before you plan to harvest.  This helps to reduce cleaning after harvest.

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Tomatoes are All Vines and Few Fruits

4 Comments / Las Vegas, Mohave Desert, tomato growing mojave desert /

Good looking tomato transplant for home garden Q. With five tomato plants all I really get is beautiful, huge green vine, why don’t I get tomatoes? Being from East coast, I sure miss good tomatoes. A. Tomatoes are difficult to grow here. The reasons are due to our poor soil conditions and our unpredictable weather mostly. Most homeowners fail to get a good crop of tomatoes because they plant them too late, they don’t give them enough sunlight and they over fertilize them.           The best years for tomato production are when we have a long cool spring. Some of the worst times we have for tomato production are when the spring temperatures fluctuate wildly from cool to hot.           The best tomato transplants are about 6 inches tall, dark green and stocky. I don’t need to tell you that they should look healthy and free from what appears to be disease or insect problems. Look at the plant. It should be healthy or don’t plant it. Planting should occur in early March unless you have a very warm spot that can protect the plants from freezing temperatures and strong winds. Tomato staked and caged           Good soil preparation is important for tomato production. All that is necessary is good quality compost added to the soil and the soil give the chance to age and mature with this compost. Tomatoes should be fertilized with a high phosphorus fertilizer at the time of planting and not fertilized again until you see fruit. Fertilizing the plants regularly can cause them to produce lots of vine and little to no fruit.           It is important that the plants have enough room to grow and produce. When they are placed in cages or staked they can be planted closer together. When they are allowed to sprawl on the ground they must have more room and we usually see higher losses of the fruit.           If tomato plants are placed too close together they tend to shade themselves and produce very few fruit. They also tend to get more disease problems if planted too close together because of a lack of air movement. Collection of tomatoes grown at The Orchard; sweet 100, old ivory egg, black from tula, snow white, yellow pear           Like most vegetables that produce something we eat from a flower, they need a minimum of 6 to 8 hours of full sunlight for good production. With sunlight less than this they tend to get leggy and not flower very much. The best sunlight for them is sunlight in the mornings and early afternoons. The worst time for them to get sunlight is if it is only in the mid to late afternoons.           It is usually best to cage them or stake them. Don’t let them grow into each other or they will shade each other and reduce air movement through the vines. This will lead to disease problems. Don’t be afraid to thin out the canopy if it gets too dense.           If you have prepared your soil well and have enough sunlight there is no reason cherry or grape tomatoes should not produce for you. These are the easiest to grow here and are usually nearly always successful.           If you have problems with cherry or grape tomatoes, I would suggest that you pay particular attention to soil improvement, the amount of sunlight they are receiving and your planting time. I hope this helps.

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Renovating a Dead Lawn Inexpensively

Leave a Comment / repair lawn, starting a lawn /

Q. I have an interesting, (and possibly complicated) task ahead of me that I’m hoping you can advise me of.  I have just rented a home in McNeil neighborhood.  This is the neighborhood that I grew up in and am very happy to have returned.  Both of my brothers own homes here and at some point I hope to as well.            The issue is that the home I have rented has gone at least a year or two unoccupied.  The owners simply shut off all the water and allowed everything to die.  Now I always remember this home from years back…lawn and shrubs meticulously kept.            What I need from you is your advice for getting the lawn back.  Owners have not committed to fixing or replacing it with a new landscape…its up to me.  If I owned this home, yes, I would take out a sizeable portion of it and change it to something more desert friendly…..but I don’t.            I need to get this lawn redone, but at as little a cost as possible.  I’m not re-sodding it of course.  So now its July and obviously I’m not doing anything now.  When fall comes around, what steps would you do if you were in my position?  I really appreciate it.  I would be happy to send pics if it helps.  Thanks again, Bob! In head to head coverage the water from a sprinkler should be thrown all the way to the neighboring sprinklers A. Sight unseen, I would probably rough up the soil a bit and reseed directly into the old lawn area. I would do start about September 1 and make sure the sprinklers have good coverage. The water from the heads should throw far enough to reach neighboring sprinkler heads.           This would be head to head coverage and you will need this for a decent lawn. Replace broken heads, straighten any sprinkler heads that are crooked or leaking. Change out all the nozzles so they are the same type if the system was designed well. If you know the distance between heads you can go into any sprinkler shop and get the right nozzles. Dethatcher or power rake           Next run the sprinklers a few times and I would spot spray any existing bermudagrass with Roundup and kill it or at least set it back well. Then in about 7 days later I would rent a power rake and power rake the dirt just to loosen it up and get it ready for seeding. I am assuming it was in lawn before so the soil should not be in real bad shape.           Buy a decent tall fescue seed mix, not K31 or Kentucky 31 seed unless you plan to run cattle on it. It will be expensive but one of the best places to spend money. K31 is coarse textured and you will probably not like it unless you like pasture grasses.           In about mid-September to Oct 1 seed the lawn area with about 10 to 12 pounds of seed every 1000 square feet. This is a little high but birds may be in and steal some seed. You can go higher than this if you want. Put a starter fertilizer down with the seed that is high in phosphorus. 16-20-0 is fine.           Apply it at about six pounds of fertilizer for every 1000 sq feet. Cover the seed with topdressing, lightly. The topdressing should just cover the seed and no more. Run the sprinklers three times a day until the topdressing is thoroughly wet but stop before any water starts to puddle or runoff to low spots.           If birds are a problem get one of those motion sensors attached to a sprinkler and put a hose on it to scare the birds. The seed should be up in 7 to ten days. Mow when it is tall enough to mow and use a recycling mower or a mower with a recycling blade on it.           Lightly fertilize every two months. That should be it. The major places where you can mess up will be not getting your sprinklers working well and applying water evenly, covering the seed with too much topdressing and buying cheap seed.

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July todo: Pick early apples

Leave a Comment / anna apple, Dorsett Golden, summer apples /

Anna apple in the Mojave Desert Pick apples. There are two pretty good apples for our desert climate that ripen right about now; Anna and Dorsett Golden. One other that deserve honorable mention is Einshemer. Generally speaking though most people don’t want apples in midsummer thinking of them as more of a fall fruit. Secondly, apples seem to be better quality when they mature in cooler weather.           When you are picking apples or any fruit for that matter, pick in the early morning hours or evening hours. Most apples do not continue to ripen once they have been removed from the tree. If apples are left outside for any length of time after they have been picked, make sure you put them in the shade and do not leave them in direct sunlight. Try to get them refrigerated and in high humidity as soon as you can.

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