This nectarine has a canopy which is too dense and should have been summer pruned. Next week on Saturday, April 30, 2011, I will be giving a demonstration on summer pruning fruit trees at the UNCE Orchard. Summer pruning is used to help keep standard sized fruit trees, dwarfed, by robbing them of their excessive spring growth. Most summer pruning can be done with your hands and does not usually rely on any pruning equipment. The class will start promptly at 9 am and last about one hour. No registration or fees are required. Call the Master Gardener helpline at 702-257-5555 for directions to the UNCE Orchard. The purpose of summer pruning is several fold. 1. First it removes unwanted growth before it has a time to mature and aids in the dwarfing process of fruit trees. 2. It opens the canopy for more light penetration so that fruit quality is improved but not so much that it might cause sunburn of limbs and fruit. Young,current season growth is easily removed using your hands and pruning equipment is not usually needed. Timing is important. It is done at a time of year when it is easily removed and after spring growth has been pushed from locations where it is not wanted. When done in April, new growth can be removed easily by pulling down. If it is done too late, this new growth will be difficult to remove by pulling. The type of growth I focus on most often is growing straight up (suckers), growing straight down, toward the interior of the tree, growth which is crossing or interfering in some way. Remember that the spring growth of peaches and nectarines (those fruit trees that produce fruit laterally along one year old wood) will be needed next year for fruit production so be careful not to remove too much. Fruit trees at the Orchard are kept at about 6 1/2 feet tall so new growth growing above this is also frequently removed.

Fruit tree evaluations were made from 1993-2008. Most of the fruit tree selections were provided by Dave Wilson Nursery for research and demonstration purposes in the Eastern Mojave Desert of southern Nevada. More general information about these fruit can be obtained by visiting their website at http://www.davewilson.com/homegrown/homeindex1.html Almonds – Most almonds do extremely well in southern Nevada and make excellent landscape trees. Recommended rootstock: Nemaguard but others do well here as well Top Choice All in One – Genetic Dwarf, Self pollinating Garden Prince – Genetic Dwarf, Self pollinating, flowers white with purple Notable Mention Carmel Neplus Ultra Nonpariel Price Under Review None at this time Apples – Not all apples do well in southern Nevada and range from “best apple ever tasted” to “tasteless” depending on variety Recommended dwarfing rootstock: M111; avoid extreme dwarfing rootstocks due to fruit sunburning Top Choice Dorsett Golden – Early Season, yellow fruit Fuji – Mid Season, orangish-red fruit Pink Lady (Cripps Pink) – Late Season, red over green fruit Notable Mention Anna Einshemer Gordon Mutsu (Crispin) White Winter Pearmain Under Review Akane Arkansas Black Asmead Kernel Babe (Genetic Dwarf) Gala Granny Smith Red Fuji Scarlet Sentinel Columnar Yellow Newton Pippen Apricot – Most apricots do well in southern Nevada and have wonderful flavor Recommended rootstock: Nemaguard preferred but others have performed well Top Choice Blenheim (Royal) Flavor Delight (Aprium; actually a plum apricot hybrid but fruit marketed as an apricot) Gold Kist Moorpark Royal Rosa – excellent landscape tree Notable Mention Canadian Blenheim White Chinese Early Golden Flora Gold Katy – excellent landscape tree Under Review (Early results are good on all) Autumn Glo Early Autumn Goldcot Harcot Tomcot Aprium – Plum apricot hybrid that does extremely well in our climate Recommended Rootstock: Nemaguard but others have performed well Top Choice Flavor Delight – See apricot Asian Pear – Performs surprisingly well in our climate and we are currently working on increasing the size and quality of the fruit Recommended Rootstock: OHxF333 but others have performed well Under Review Chojuro Hosui Kikusui Shinko Shinseiki Tsu Li Twentieth Century Ya Li Blackberry – Struggles in this climate and soils but produces acceptable fruit Top Choice None at this time Notable Mention Rosborough Womack Under Review None at this time Cactus, Nopal – For fresh vegetable (nopalitos) and fruit (tuna) and extremely well adapted for this climate. Being removed from trials in 2010. Top Choice Copena F1 Copena V1 Notable Mention None at this time Under Review None at this time Cherry, Sweet – Inconsistent fruit production and not reliable in this climate Top Choice None at this time Notable Mention None at this time Under Review Bing Black Tartarian Craig’s Crimson Lapins Royal Ann Cherry Plum – Hybrids between cherry plum and Japanese plum Recommended Rootstock: Nemaguard preferred but others have done well. Top Choice None at this time Notable Mention None at this time Under Review Delight Sprite Figs – Most figs do well in this climate. Top Choice Black Mission – dark purple skin with strawberry colored flesh Janice – greenish-yellow (white) skin with light greenish amber flesh with few seeds Notable Mention Kadota Under Review Brown Turkey Celestial Flanders King (Desert King) LSU Purple White Genoa Grapes, Table – Nearly all table grapes do well in our climate Top Choice Blush Fantasy Flame Notable Mention Harmony Himrod Perlette Thompson Seedless Under Review Italia Princess Black Monnuka Grapes, Wine – Many wine grapes are very productive in our climate but taste evaluations and winemaking with the fruit is underway Recommended Rootstock: own roots, 110R, 1103P but others have done well Top Choice None at this time Honorable Mention Primitivo Summer Muscat Zinfandel Under Review Alicante Bouschet Cabernet Franc Cabernet Sauvignon Chardonnay Grenache Marsanne Merlot Sangiovese Sauvignon Blanc Syrah Noir Tempranillo Viognier Jujube – Chinese Date or Indian Fig does very well in our climate Top Choice Li Honorable Mention Lang Contorted Under Review None at this time Nectarine – Nectarines do well in our climate but vary in fruit quality Recommended Rootstock: Nemaguard but others have done well in our climate Top Choice Arctic Star Honorable Mention Acrtic Glo Arctic Rose Desert Dawn Desert Delight Double Delight Under Review Arctic Gold Garden Delight – Miniature Goldmine Independence Liz’s Late Necta Zee – Miniature Panamint Peach – Peaches do extremely well in our climate and have received praise from internationally recognized chefs Recommended Rootstock: Nemaguard but others have performed well Top Choice Babcock – White, mid season Eva’s Pride – Early season May Pride – Early season Mid Pride – Mid season Starks Saturn – Donut peach, white flesh, mid season Honorable Mention Arctic Supreme – white flesh, mid season Desert Gold – Earlitreat – Earliest producer Early Amber – Early season Early Elberta – Elberta – Mid season FlordaPrince – Early season Red Baron – Showy flowers, good landscape tree, mid season Red Haven – Mid season Under Review Arctic Jay – White Carnival Double Jewel Elegant Lady – White Fairtime Gold Dust Harken Indian Free July Elberta (Kim) Nectar White – White O’Henry – Late season Rio Oso Gem Snow Beauty – White Snow Giant – White Snow King – White Strawberry Free – White Sugar Lady – White Summerset Sweet Bagel – Donut peach, yellow Tra Zee – Late season Tropic Snow -White White Heath Cling – White White Lady – White Peach, Miniature Top Choice None at this time Honorable Mention Bonanza – Mid season El Dorado – Mid season Pix Zee – Mid season Under Review Honey Babe Garden Gold Garden Sun Pear, European – European pears do quite well in taste but suffer from visual appeal Recommended Rootstock: Any Top Choice Kieffer – Salad pear, nicknamed “Jicama pear” with flavor resembling an Asian pear, good for canning and baking Honorable Mention Bartlett Monterrey Red Bartlett Under Review Bosc California Comice D’Anjou Hood Persimmon – Struggles in this climate but fruit is good quality Top Choice Fuyu Honorable Mention Hachiya Under Review Chocolate Coffeecake Giant Fuyu Niunai

Q. We purchased a home two years ago with two existing magnolia trees in our front yard. The trees are about 8 feet tall, have some leaves on them but they don’t look overly healthy. I’ve treated both trees with soil acidifier and a product that contains an insecticide and fertilizer each year. We also have an automatic fertilizer injector for the yard. Do you have any other recommendations for them? Two magnolia planted on the east side of Las Vegas showing some signs of stress with dieback on the tops and sides. Old magnolias for Las Vegas A. I have said this before but it probably doesn’t hurt to say it again. When we plant trees, shrubs or any other plant for that matter that is out-of-place in our desert environment then it will cost us more time, energy and money to take good care of it. Magnolia is clearly out of its element here in the desert. So it will require more from you to make it healthy and keep it in good shape. The acidifier might be of some help but you can get excellent acidification from compost and decaying organic matter such as wood mulches.  I hope they are not planted in rock mulch. That will be their doom if they are. Try adding compost around the tree and watering it in if you can. The fertilizer you’re using is fine but I would also recommend an iron chelate as a fertilizer applied now which contains EDDHA in the ingredients. Magnolias planted near a west facing wall on a building in rock (boulder) mulch in Las Vegas. OMG. You can skip the insecticide treatment. Magnolias are not a good choice for this climate and I will not give you a lot of hope in getting these to large trees. Enjoy them while you can. We don’t see many large ones here for a good reason.

Wind Damage on Plum Leaves Q. Something is eating the leaves of my small grapefruit tree. I have checked it often to see if I could see the pest that was the culprit, even at night, and cannot find anything. What do you recommend? A. Without seeing it I am not sure anything is eating your grapefruit leaves. Wind damage to the leaves is the most common reason for damage to citrus leaves that resembles feeding damage by insects. We did have some pretty good winds recently. Wind damage most resembles tearing, shredding or ripping of leaves. I would not apply an insecticide if you are not convinced it is insect damage and then only if the damage is not recoverable by the tree without your assistance or interferes with fruit production. Wind damage to persimmon leaves.

 Hoophouse with 30% shade at The Orchard Q. I have to build a small raised bed for vegetables and herbs. I want to provide protection from the wind and cold and, later, the summer heat. The sun screening in the stores are the 25-30% type. What is the best sun screening level for sun screen? A. We generally use about a 30% shade cloth for most vegetables. Even at 30% this is too much shade for some vegetables such as okra which does much better in full sun. Okra originated out of the area of northern Africa we now call Ethiopia and Eritrea. This probably explains why they don’t like much shade and enjoy our full sun. I would not go above 30% shade for those vegetables which we value for their flowers and subsequent fruit that develop from flowers. Decreasing light will affect flower production. For leafy vegetables you can go higher in percent shade, perhaps in the 40% shade category.

Sap coming from apricot limb. Q. Our mature apricot tree has been a good producer of sweet apricots during the 7 years we have owned the house. This year the apricots were not sweet and there is sap coming out of one of the limbs. Now, after harvest, several limbs are dying. I am attaching a photo of the damage. Is there anything we can do to save our tree? A. Sap coming from the limbs of apricots is usually an indication of stress or damage of some sort. Apricots are not as notorious as peach or nectarine for getting borers or boring insects in their limbs. Damage from borers is typically on the upper surface of limbs because of sunlight intensity or sun damage and it’s very thin bark. Damage from sunburn borers can cause sap to flow near the damaged area.Your picture seems to indicate sun damage but that can also be from damage from boring insects. By late June or July if this damage were from boring insects or borers you would see a limb which has leaves which have totally turned brown and perhaps limb death. Branch death would be a clear indication of borers and of course the limb should be cut out and removed. Diluted white latex paint for controlling sunburn and consequently borer damage. There is no chemical spray that you can safely up like to apricots for controlling borers. We usually rely on whitewashing limbs and the trunk with a dilute white latex paint and remove limbs that are heavily damaged. This white latex paint is diluted with an equal amount of water, mixed and applied with a brush or sprayer on the upper surfaces of limbs, western and southern exposed areas of the limbs and trunk. This white wash helps to decrease damage to the limbs from sunburn and subsequent infestation by boring insects.

Iron chlorosis in Indian hawthorne due to poor soil development from lack of organic decomposition of rock mulch. Q. Following your advice, I am planning to replace all of the stone mulch under and around the existing shrubs in my yard and replace with bark mulch from the orchard stock pile. I have been told that bark mulch attracts cock roaches. Is this your experience? A. Wood mulch will attract quite a number of animals and foster plants that contribute to the breakdown of the mulch and roaches do contribute to that. These include mushrooms, earthworms, larvae of beetles such as grubs, gnats, and others. Mulches that decompose will attract decomposers.Roaches tend to congregate in irrigation boxes in the landscape and these should be treated periodically for control if this is a problem. I normally tell people to keep the wood mulch a couple of feet from the foundation of the house.Rock mulch will give you a more “sterile” environment and if that is what you prefer then stick with rock mulch. There is nothing wrong with rock mulch if it is used with plants that can tolerate rock mulch such as most desert dwelling plants. However, decomposing wood mulch has many, many advantages for plants compared to rock mulch which adds nothing back to the soil and most plants will perform better with wood mulches. If you would like a copy of the benefits I can forward this information to you or any of my readers.

Mexican papaya in containerQ. I saved some papaya seeds last year and planted three of them in the spring. To my surprise all three began to grow. It’s hard to tell but the three plants are different sizes. I’d like to transplant them into individual 15 gallon pots. I read where they do not like to be disturbed once they start growing. What might be the right time to attempt that? Meanwhile I need to keep them somewhere once it gets cold outside. What would be the best way to keep them through the winter? And what are the chances they would ever bear fruit some day? A. Master Gardeners who attend my classes are very familiar with me saying, “You can grow any plant in the world in Las Vegas. It depends on how much time, energy and money you want to use to make it happen.” Rare fruit growers in Phoenix grow papayas outside with some freeze protection applied during the coldest part of the winter. We are not Phoenix but we do have some similarities.This is what you need to know about papayas to be successful. Papayas prefer rich, tropical, acidic soils. They will not withstand temperatures much below 32F or freezing. Papayas do not like direct sunlight from the late afternoon sun and would prefer about 30% shade if in full sun. Papayas will die growing in soils that do not drain easily but also do not tolerate dry soils.They are heavy feeders and so require continual applications of small amounts of fertilizer. They need both male and female flowers to set fruit. Sometimes this happens on a single plant and other times it requires a male and female plant. So plant several so that your chances of getting male flowers is increased.They are normally started from seed and, as you found out, the seed germinates easily. Most of our papayas come from Mexico due to costs of production. They should transplant fairly easily into 15 gallon containers if you are careful and stake it in the new container to keep it upright and wind resistant.Keep them lightly shaded until the roots have reestablished in the container, maybe one month. They should be able to handle more sunlight after this. Some varieties of these plants may become damaged anytime the temperature reaches about 45° F, others are more resistant to this type of chilling injury. They will not handle any freezing temperatures at all and they become stunted at temperatures even slightly above this. I have no experience growing them here but it’s reasonable to assume that they would handle morning to mid afternoon sunlight but not late afternoon. They will handle some light shade but will probably not do well in fruiting if the shade is too much.These trees produce at a very young age, some produce at a younger age than others but they are also very short lived. Of course it would be best if they were in a greenhouse here and handled as a tropical plant.No one is certain how the fruit is set; whether it is by wind or by pollinators. If you’re lucky enough to keep it long enough to get flowers you may have to do some hand pollination if you do not get fruit set. Your biggest challenge will be to keep it from getting hurt during the winter and still provide enough light during the summer to encourage flowering and fruit set.

Q. I have a nice little compost pile that is about ready to spread. I read where fall is the best time to spread compost around fruit trees. Is that true? Composting wine grapes at the Orchard A. We do use compost around some of our fruit trees at the orchard. The fruit trees I like for applying compost are persimmon, Asian pear, and other fruit trees that have not originated in arid or desert climates.All of the fruit trees will benefit from an application of compost, even grapes. If you grow any blackberries or other cane fruit they will benefit as well. I usually spread compost around the fruit trees just prior to spring growth in mid January for the earliest. I will still supplement it with iron chelate. It needs two or three weeks of irrigation to begin moving the nutrients from the compost into the root zone and into the tree.