Xtremehorticulture

Xtremehorticulture of the Desert

What Makes a Good Compost?

Leave a Comment / compost test reports, compost testing, desert, good compost, Las Vegas, Mohave Desert, Mojave Desert, nevada /

Compost quality can be hard to judge. Part of the quality is what you see and what you feel and smell. It should smell good. A good quality compost should smell good. It should not have any off odors. No smell of rotten eggs, no smell of ammonia. Compost should look and smell good. It should look good. It should be dark brown when moist. It should be ALL brown and not some of it brown and some of it not. It should be consistently brown throughout. You should not be able to discern or see any of the products used to make the compost. Leaves and stems should not be discernable. It should be screened so that larger materials have been filtered out. Some composts are screened with multiple screens to include 1/2 inch and smaller particles (1/2 inch minus). Some are screened even smaller than that… 3/8 inch minus or even 1/4 inch. Screening depends on its use. If it is used on let’s say a golf course on greens then large paricles of compost will interfere with the roll of a golf ball when grass is cut at 3/8 or 1/4 inch. It should be cool. Good quality compost has matured to the point where it no longer produces alot of heat. Compost that is still hot has not finished composting and is immature. Part of the compost process is setting it aside to “cure” after the composting process has completed. Compost also has qualities that you cannot see. Pathogens. Generally speaking, commercial composts usually have fewer pathogens that can affect human health than homemade composts. Commercial operations can spend time monitoring and managing a compost pile more effectively than a gardener. Good commercial operations monitor the temperature and moisture contents (and even the oxygen and carbon dioxide levels) so they know when to turn the pile for better aeration, better temperature control and more even processing of the compost. Techniques like in-vessel composting and windrows can generally make a product that has fewer human pathogens in it than static piles that are not monitored carefully. Chemistry. Even though not considered a fertilizer by law, composts contain plant nutrients. They will add “fertilizer” to a garden. They add lots of other things as well. Trace minerals are present along with organic acids that improve soil chemistry. It is always a good idea to ask for compost test results. All commercial compost operations have them. They should provide a copy if you ask them about it. There are potentially some things in compost that we need to take a close look at. Salts. All composts will have salt in them. Fertilizers are salts. Some salts are good and some are not as good. Major salts that can be problems for us in our soils are salts of sodium, chloride, sulfates and boron. Salt levels should not be excessive and the salts that concern us should be minimized. I will give more information on these in future postings. Composts that come from large urban centers can contain heavy metals. In commercial composts the level of heavy metals allowed in commercial composts is highly regulated and monitored. They are not in non commercial composts. Biosolids. Some composts contain biosolids. Biosolids is the preferred name to sludge. This is becoming more and more common as our federal and municipal governments are trying to find an alternative to placing them in landfills. This will become even more common in the future. The use of biosolids is highly regulated in the commercial compost industry with federal limits established by the federal government. I will be discussing this important issue in future postings. In short, you should and must know what is in your compost before applying it to your gardens. Ask for reports on what is in the compost you are purchasing. Make sure that the facility is submitting samples regularly to compost testing facilities.

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Figs Dropping From Tree

Leave a Comment / desert, falling off, fig fruit, green, irrigation, Las Vegas, Mohave Desert, Mojave Desert, mulch, nevada, not mature, small /

Q. We planted a fig tree a couple of years ago. Year before last it produced a couple of figs. Last year there were perhaps a dozen figs which never got larger than a small grape. These did not emerge until November and never grew to full size. The tree was fertilized with 16-16-16 commercial fertilizer, and had plenty of water. Can you tell us why the fruit did not mature and what we might do to have a better result this next season? A. The usual problem is not watering at the right time and keeping the soil moist during production of fruit. We can get two good crops of figs here. The first one is called the Briba crop and is borne on last year’s wood (2013 growth). This is the Briba crop. Notice how the figs are developing on older, brown wood from last year. You can see the new growth pushing from the terminal bud, is green and about two inches long.             The second crop is the Main crop and grows on the current season wood (2014 growth). If the tree is pruned or last years wood is killed by freezing weather, you will only get a main crop. This picture shows you the larger Briba crop still developing at the bottom on older wood. Above these fruit are smaller fruit still developing on this years growth, the main crop. The Briba crop will be harvested while the main crop is still developing.             The main crop occurs when it gets hot and if the tree is not getting enough water the figs will get button sized, get hard and drop off. There is a potential third crop in about September and October but the weather does not stay warm enough in the fall for it to mature.             This third crop will get button sized and will fail to develop due to winter weather coming in. That third crop may form without the summer crop if the tree is not getting enough water. Then in the fall it is getting enough and tries to set fruit but it is too late and fails. Although this is another readers picture, this is what this reader is probably talking about. Late season figs never get to ripen. However, if you keep the soil moist during the summer months, the first two crops will ripen.             I would mulch around the tree with about four inches of wood mulch and cover the soil to a distance of about six feet from the trunk. Water in a basin around the trunk about six feet in diameter.             The basin should be able to hold at least two inches of water but four would be better. Fill the basin with water each time you irrigate. Water once a week now, twice a week in May, three times a week in June, drop it to twice a week in September and once a week mid October.             Once the leaves fall off in winter you can water about every 10 to 14 days. Fertilize once in February with a fruit tree fertilizer or four fertilizer stakes per tree, one in each quadrant of the irrigation basin.

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What To Do to Fruit Trees Now

2 Comments / desert, how much to water fruit trees, Las Vegas, Mohave Desert, Mojave Desert, nevada, when to fertilize, when to prune /

Q. What should we be doing to our fruit trees right now? A. You should be finishing your winter pruning now. Bloom on some fruit trees started early this year and if you haven’t finished it you can still go ahead while it is in bloom. Be careful of the bees.             Hold off on pruning grapes until later in February when the chance of freezing temperatures has passed.             Fertilize your fruit trees now if you haven’t. Use a balanced fruit tree fertilizer high in phosphorus. If you miss this application you can use three or four liquid applications to the leaves (spray) a week apart in the coming weeks.             If you suspect you will have yellowing due to an iron deficiency, apply the iron chelate EDDHA to the base of the tree with your irrigation water. Trees susceptible to iron problems include peach, nectarine, plums, apricots, almonds, apples and pears.             Before or immediately after bloom, but not during bloom, apply dormant oil to limbs and trunk making sure you spray the undersides of the leaves, not just the tops.             Irrigations should be once a week as soon as you see new growth. Newly planted trees can receive 5 to 10 gallons. Trees that are up to ten years old should receive 20 to 30 gallons each time you irrigate. Irrigations should be applied to at least half of the area under the canopy.             Prepare for thinning fruit trees of excess fruit in about a month. Summer pruning will occur in about April. Watch for my postings on future activities and when to do them.

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Potted Meyer Lemon Flower Drop

1 Comment / container trees, desert, fertilizer, flower drop, freeze damage, fruit drop, irrigation, Las Vegas, Meyer lemon, Mohave Desert, Mojave Desert, nevada /

Q. You helped me before with my Meyer Lemon, so I hope you have an answer for this one. My tree is in a huge pot. It is about 4 years old.             Last Spring, it had massive flowers (yum) and a lot of little green buds followed. Then every single one of those buds turned black and dropped off.  Not one remained. I want to figure out why and change what I am doing so this never happens again.             The plant is fertilized with granular fertilizer 2x a year — early spring and late summer. It gets moisture and hasn’t dried out.  However the leaves could look more beautifully green. Sometimes, some of them curl and are not quite bright green.             I do not know if the two issues are related, but I sure hope you have a suggestion. A. Sounds like you had post bloom fruit drop. Fruit drop can also occur during summer months and just before harvest. The usual reasons for post bloom fruit drop is usually some sort of stress.             Four years is getting up there for being in the same pot without repotting. You might consider repotting and adding some new soil to the mix. Meyer lemon flowers             I know you said it had adequate water but if it went through just a few hours of drought during or just after pollination, fruit drop may occur. If we have some freezing weather during or just after flowering, that can cause the fruit to abort too.We had some on January 6 and 8 in parts of the valley.             When watering, make sure about 20% of the water that you apply runs out the bottom of the container each time you water. This is important for flushing salts from the soil.             Another possibility in containers is overheating them. If in direct sunlight and the outside of the container gets too hot and transmits this heat to the soil, this can cause stress and cause fruit drop.             Proper fertilization is important. Over fertilizing fruit trees, excess nitrogen, can cause fruit drop. And finally less commonly some insects such as scale or mealybug infestations can cause fruit drop as well.             What to do? Make sure your container, the soil volume, is big enough to handle wide swings in temperature and water. Monitor both closely. You might find a houseplant moisture meter to be helpful.              Keep the outside of a plant container out of the hot sun. Double potting a container is  helpful to keep the soil temperature down. Watch for freezing temperatures at bloom time and cover the plant.             Water the soil just before the heat of the day. Wet soil heats up more slowly than dry soil. If we have any frost during bloom it will affect fruit production.

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Monthly Weather and ET Report from the UNCE Orchard

1 Comment / ET, evapotranspiration, Las Vegas, nevada, southern nevada, weather /

We had freezing temperatures at night on January 6 and 8th. Winds did not compound the problem. Humidity dropped to single digits twice during the month. No major rainfall events. ET was about 2. 4 inches during the month of January. Generally speaking, irrigation should have added about 2 inches of water in January, 2014. The UNCE Orchard is located at 36 degrees North Latitude and 2000 ft (666 meters) elevation in the Mojave Desert. The soil temperature was reset from 6 inch depth to 2 inch depth on January 21. This is why the range became so scattered starting January 21. If this scattering continues we will reset it a bit deeper. This temperature is used to estimate seeding dates for direct seeding into the raised beds.

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Vegetable and Herb Planting Calendar Re-Posted as PDF

Leave a Comment / desert, herbs, Las Vegas, planting calendar, vegetables /

I made some changes in the one I posted earlier and embedded it from Scribd as a pdf document. Please let me know if you have trouble downloading it by posting here on the blog. This has been put together for elevations of about 500 ft (160m) to 3000 ft (1000m) elevations at 36 degrees N. Latitude in a desert environment. Vegetable and Herb Planting Calendar

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Desert Green Presentation on Fertilizing Woody Plants with Notes

Leave a Comment / bob morris, desert green conference, horticulture conference, how to fertilize trees and shrubs, Las Vegas, presentation /

Prescription Fertilizers for Trees and Shrubs Notes to the PowerPoint Presentation Desert Green 2013 Robert Ll. Morris, Emeritus University of Nevada [email protected] Desert Green is a conference held annually in Las Vegas for landscape professionals. This is a copy of my presentation on PowerPoint and my notes for the presentation. Slide 1. Title slide with contact information. Slide 2. Characteristics of desert soils. Desert soils contain very little organic matter and they are chemically and physically undeveloped. Because they contain so little organic matter in them, they have very little structure or are structureless. For this reason they sometimes tend to drain poorly. Their alkalinity or pH is normally high. Frequently they contain high levels of salt of all different types. If these soils have never been developed, they can change rapidly both physically and chemically when water is applied to them. Slide 3. There are 16 or 17 nutrients that are essential to plants. Several of these are needed in large amounts and we call these major elements or macronutrients. The rest of the nutrients are needed in a much smaller amounts, still just as essential. These are referred to as minor or micronutrients. All of these nutrients are essential to plant life and if any one of them is missing, the plant will die. If any of these are insufficient for the plant, it can display visual symptoms, poor health and subject to increased disease and insect problems. Bags of fertilizer traditionally contain nitrogen, phosphorus and potassium if they are a complete fertilizer. These three nutrients are called NPK and their relative amounts determine the fertilizer ratio. Carbon, hydrogen and oxygen the plant obtains from air and water. Most desert soils contain adequate amounts of calcium, magnesium and sulfur. Of the minor elements, iron, manganese and zinc can be in short supply to plants because of the soil’s alkalinity or high pH. In most desert soils were landscape plants are being grown, nitrogen is most commonly found in the greatest need by plants. Second to nitrogen is probably available iron. Slide 4. The three numbers on the fertilizer bag give an indicator of the amount of nitrogen, phosphorus and potassium contained in the bag, in that order. Sometimes there is a fourth number present. Although not legally required it usually represents the amount of sulfur contained in the fertilizer. The fertilizer ratio tells us the relative amounts of NPK. For instance, if the fertilizer has a ratio of NPK of 3:1:2 then fertilizers such as 12-4-8 and 21-7-14 would represent this ratio. Slide 5. Although all nutrients are needed for a plant to live, nitrogen represents the one nutrient that is universally in short supply. Nitrogen helps to drive plant growth and causes increases in size. It stimulates increased leaf and stem growth, causes a darkening of leaf color, hastens plant growth after winter dormancy and helps to increase the amount of food manufactured by the plant. If applied too late in the year, it will decrease a plant’s hardiness to freezing temperatures. Most nitrogen fertilizers are pure white in color. Most nitrogen fertilizers dissolve easily in water and moves readily through the soil with irrigation water. Slide 6. Lack of nitrogen shows up in plants as slow growth, foliage with a light green color and a lack of density in the canopy. Slide 7. In pine trees a lack of nitrogen shows up in the same way. This translates to a canopy which is not full, small candles and needles occupying the ends of branches while most of the branch is without needles. Slide 8. If too much nitrogen is applied, plants might grow rapidly with an extremely dense canopy and very dark color. When nitrogen is applied in large amounts it can cause scorching to occur on leaves and tip dieback on needles. In some cases it may cause plant death. Applying too much nitrogen is a waste of money and causes environmental problems as well. Slide 9. Adequate amounts of phosphorus is most closely related to good root growth and plant establishment, flowering and fruit production, seed and oil production. When soils are cold and wet this can lead to a lack of phosphorus taken up by plant roots. There is a quick recovery by plants as soon as the soils begin to warm. Phosphorus fertilizers are typically dark in color, usually dark gray or brown. Slide 10. Unlike nitrogen, phosphorus can stay present in the soil for long periods of time, does not dissolve easily in water and does not move through the soil unless the soil is very sandy. Phosphorus levels can build in the soil with repeated applications of high levels. In some cases phosphorus can build to toxic levels with repeated applications. Phosphorus can interfere with other nutrients, iron in particular. Over application is a waste of money and can lead to environmental pollution. Slide 11. Deficiency of phosphorus can sometimes lead to purple discoloration of the plant which disappears when phosphorus becomes available again. This is very common to many plants in cold, wet soils. Slide 12. Potassium is sometimes underappreciated in fertilizer applications. Deficiencies are hard to see since a deficient plant gives no outward symptoms. Potassium chloride, a common potassium fertilizer used in mixing fertilizers together, as a reddish-brown color. Slide 13. Over applying potassium usually will not harm anything and it does not build up in the soil like phosphorus does. Deficiencies of potassium can lead to a plant’s decreased tolerance to stresses such as heat, cold, freezing, disease and others. Slide 14. Nutrients needed in smaller amounts. Of the seven nutrients needed in much smaller amounts, iron, manganese and zinc are the ones most likely to be in short supply for plants growing in alkaline soils. Of the three, iron is by far the one found most efficient in plants. This is odd because iron is one of the most abundant minerals on earth. The key to its limited availability to plants is the pH

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Horseradish is Best Harvested in Cool Months

Leave a Comment / herbs, how to grow, how to prepare, Las Vegas, recipes, will it grow /

Q. I really enjoy the blog. Had a question for you.I planted some horseradish about a month ago. It’s growing nicely (I think — first time I’ve planted it). But I have five-six nice big leaves coming off the plant.I was wondering when I can tell it’s ready for harvest. I’ve looked online, but most of the instructions involve spring planting and a fall harvest. Since I planted in fall, per the extension service instructions, is there a way to know when they’re ready to harvest? A. Horseradish does quite nicely here for a northern climate perennial but it needs time to develop its roots where we derive the spicy condiment. After the leaves have fully established, it will take two or three months, at a minimum, for harvestable roots (rhizomes). It is in the mustard family where many members have spicy leaves and stems used in salads. This is perennial mustard so it sprouts from its underground rhizomes each year. The rhizome can be dug in the fall or spring, divided and replanted again to create new plants.  In colder parts of the United States most planting is done in the spring. But here in the semi-south (actually we are in a ‘Transition Zone’ climatically between north and south), we can plant a lot of things in the fall that are recommended for spring planting in the north. You could plant during our entire winter if you are careful and have a warm microclimate, or create one, in your garden. Our real “winter” here is the summer months which are more brutal to plants than our winter.   If your plant got two or three months of good growth before fall I would’ve told you to harvest it, divide the rhizome and let it heal and then replant. Now that we are in the second week of November I think it is a little dangerous to recommend that unless you have that warm microclimate I was talking about.  I would wait until February to mid-March to dig it, divide the rhizome if it needs dividing, let it heal for 48 hours and replant it. If the rhizome has not given you enough growth for it to be divided, then I would just replant it.  Horseradish is a tough plant. In some parts of the country it is so tough it can be invasive in the garden. Any little section of the rhizome left in the ground after digging can create new plants. So you do not need a big part of that rhizome to start a new one. There are some critical gardening tips that you need to follow when planting or replanting horseradish or any plant started from rhizomes. Make sure the knife you use when dividing the rhizome is clean and sanitized. The cuttings you prepare for replanting can be anywhere from 3 to 6 inches in length. Plant the rhizomes horizontally about 2 inches deep and about a foot apart. Don’t plant until all fresh cuts, or any damage to the rhizome, has had time to heal.  Heal the rhizomes by placing them in a warm spot (warm compared to outside, 60F or so) for 48 hours. This will allow any cuts or damage to begin to suberize or begin the healing process.  Be careful not to re-damage the rhizomes when planting. Those parts of the rhizome that recently healed can be damaged easily.  Make sure the soil has been prepared with good quality compost to a depth of 18 inches. Horseradish likes composted manure and prefers to be kept moist but not overly wet. It can survive droughty conditions but is not productive. It likes surface mulches 2 to 3 inches deep that keeps the soil moist and cool. You should dig them during the cool fall or spring months for harvesting and replanting for best flavor. Use the large central root for cooking and the smaller, side roots for planting. Horseradish root will go bad very quickly after you start shredding or grating it for cooking. The root oxidizes quickly which ruins the flavor. Use it as soon as possible after harvest. Shredded or grated horseradish root can be stored in vinegar for short periods of time as this will help keep it from oxidizing. If you are storing it in the refrigerator, keep the roots moist and in long pieces until you need it. It will probably store in the refrigerator for about 3 to 4 weeks in more humid areas such as the crisper. It can store longer than this but you would need more sophisticated storage than just a refrigerator.

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Recommended Varieties of Almond, Pluot, Nectarine, Pear for Hot Desert Climates

1 Comment / best varieties, Las Vegas, southern nevada /

Q. We have had several trees die over the past year so we are looking for replacements that will do well here.  We do have a Kiefer pear which produces really small, rock hard pears that never seem to ripen. Some suggestions please for almond, nectarine, pluot and apricot. A. If I were to plant only one almond tree, it would be Garden Prince. It is smaller than the other almond varieties and the flower is a beautiful purplish white instead of plain white. For a home landscape that needs a smaller-sized tree, beautiful flowers and wonderful nuts, Garden Prince can’t be beat. It is self-pollinating so doesn’t need a second almond for pollination. Almonds in bloom at UNCE orchard             Arctic Star nectarine has a remarkable flavor in our climate. It is floral, buttery and one of the best fruits I have ever tasted. It makes wonderful sorbet. But you must remember that you will have problems with thrips with that will result in horrible scarring of the fruit if you don’t keep it under control. It must be sprayed. Nectarines at the UNCE Orchard.             Remember that pluots require a pollinator tree for improved fruit set. A good pollinator for pluot is also a great plum for our area called Santa Rosa. If you already have a Santa Rosa plum or your neighbor does, you don’t need a pollinator tree for pluot.             Among the pluots, the best tasting in my opinion is Flavor Supreme. Second on my list would be Flavor King. The problem we have had with Flavor Supreme is low fruit production even with a pollinator. Flavor King has such a large fruit set, it must be thinned. Flavor Supreme Pluot at the UNCE orchard             The second problem with all pluots is our late spring freezes in the developmental fringes of our valley which are typically colder.             When we get a freeze and they are in flower, you probably will not get any fruit that year. So expect fruit in two or three years out of every five if you live in these colder fringe areas of the Valley.             A great apricot, that is not really an apricot but a cross between an apricot and plum, is the aprium. The fruit looks identical to and is marketed commercially as an apricot. It has flavor attributes of plum and apricot in the fruit. The best aprium out there is called Flavor Delight which will be available from the UNCE Orchard. Flavor delight aprium 15 yrs old kept at 7 feet height at the UNCE Orchard             Your Kiefer pear is very different from pears like Bartlett or d’Anjou which are desert pears. Desert pears will get soft and buttery in texture if you harvest them slightly early and let them ripen at room temperature off the tree. Kiefer pear is a salad pear that is also great for canning and used in stuffing for fowl like turkey or chicken. Keiffer pear ready for harvest. Note the color change.             Kiefer pear should be harvested just like you would a desert pear. To judge when to harvest I use a change in color of the fruit and smell. The fruit color will change from green to yellowish green and you will detect a distinct pear aroma from the fruit. They will still be hard when harvested. Bartlett pear ready to be eaten and should not be harvested at this stage but earlier when there is still a hint of green             You can also sacrifice a fruit and to cut it open and check the color of the seeds. They should be dark brown when the fruit is ready to harvest. But if you compare Kiefer pear with a desert pear, you will be very disappointed. They are both great, but in different ways.

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Plant Garlic Cloves and Onion Seed in October and Early November in Southern Nevada

Leave a Comment / Las Vegas, when to plant garlic, when to plant onions /

This is the ideal time to plant garlic from cloves and onions from seed. I have grown perhaps 25 or 30 different varieties of garlic and about as many sweet onions. I have not found a garlic or onion yet that has not done well in our climate. Both long day and short day onions do well here, from Washington’s Walla Walla to Georgia’s Vidalia sweet onion. Garlic as well from softneck types to hard neck. Walla Walla onion grown at the UNCE orchard in North Las Vegas             It is too late to order garlic for planting or onion seed. You can still find onion seed in some stores. Most of the garlic is imported and not all that interesting but you can find some specialty garlic at the farmers markets or specialty stores like Whole Foods you can use for planting.  Garlic planted with drip tape and mulched with straw now harvesting scapes (flower stalks with unopened flowers)             Break down the garlic bulb into its cloves. This will leave tiny wounds on the fat end where they were attached. Select only the largest cloves for planting and the rest for cooking. Inspect the cloves very closely and if any have tiny brown spots on the skin of the clove then use them for cooking as well and do not plant them.              Leave the separated cloves out overnight and let the wounds heal. The day you plant garlic cloves, soak them in tepid water for a couple of hours first. This will speed up their emergence from the soil.              Plant these cloves in prepared garden soil about two inches deep and four inches apart with the fat end down. At this time of year, I would water these cloves daily if the soil drains easily. If your soil does not drain easily, then irrigate every 2 to 3 days. Once they have emerged you can water less often. Volunteers separating the cloves out from the bulbs for planting. These were purchased as certified disease free planting stock but you can use store bought garlic in a pinch.             Broadcast onion seed on top of good garden soil. The seed doesn’t need to be spaced far apart since you are just going to grow them into transplants and move them next March. When you move these transplants they will be planted about 4 inches apart into rows or blocks. That is when proper spacing is critical.

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