Xtremehorticulture

Xtremehorticulture of the Desert

Systemic Insecticide Questionable for Fruit Trees

Leave a Comment / imidacloprid, Is it safe to use systemic insecticides /

Q. I have a mimosa silk tree that is covered in ants.  I assume they are herding aphids infesting the leaves.  I want to use a systemic ground-soak poison.  Star Nursery has a product to be used annually.  I will use it on my shade trees (eucalyptus, California Pepper, Texas Mountain Laurel, Chitalpa) if you say a systemic treatment is appropriate. Can I also use it on my fruit trees (peach, nectarine, apricot, fig, Pink lady apple) and grape vines?  My pomegranate trees are not as infested with leaf footed hoppers as in the past, but they are there.  The kid at Star told me to just stop using the poison a few weeks before harvest, but that makes no sense to me, with an annual-use product. I don’t plan to use a systemic in my garden. A. The product that was recommended to you was probably this one. Here is a posting on my blog regarding its use. I am never a big fan in using any kind of systemic pesticide where there are food crops. Hope this helps. http://xtremehorticulture.blogspot.com/2014/03/systemic-insecticides-applied-to-fruit.html

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Curling and Twisted Growth of Citrus May Be Normal When It’s Hot

1 Comment / grapefruit tree, leaves cupping on orange tree, lemon tree, Why do the leaves of my orange tree curl /

Q. The new growth on my citrus trees (Lemon, oranges, and grapefruit) are starting to curl up at they grow. Attached are a few pictures. They are watered every three days, 12 gals per watering.   I fed them every six weeks starting at the end of Feb with a balanced citrus fertilizer.When I had a yellowing leaf problem I gave them iron and spayed the leaves with Epsom salt.  Last feeding was Sept 1. I checked some of your past blogs but could not find anything that mentioned this kind of problem. Any thoughts or suggestions. A. In our climate this is nothing to be concerned about. We don’t have a lot of citrus here so many of the insects that might cause curling or cupping of leaves are not commonly present here. Most likely what you are seeing is growth of citrus in response to our heat. I think the outer edges of the leaves become damaged or their growth slows compared to the rest of the leaf and new growth begins to distort. You should not see this in new growth in the spring. In other parts of the country where citrus is more common this could be an insect related problem or an irrigation problem. In our case here and because it’s happening on so many of your citrus it is most likely heat related and a temporary problem.

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I Have Not Been Impressed with Ambrosia Pomegranate

5 Comments / Selecting a pomegranate, Which pomegranate is best /

Q. I am very excited as I am about to plant 4 pomegranates – Ambrosia, Purple Heart, Hotuni-zigar, and Sirenvyi.   Ambrosia pomegranate A. Out of your four pomegranates I only have experience with Ambrosia. It is one of the earliest pomegranates but to be honest I am not a big fan of its flavor or appearance and neither were any of the chefs that I introduced it to. It did seem to improve a little bit in flavor after sitting in the refrigerator for a couple of weeks after harvest. Perhaps some of the other readers of this blog might be able to comment on your other selections.

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Using Nitrogen Fixing Plants To Fertilize My Fruit Trees

Leave a Comment / can I use legumes to fertilize my fruit trees, nitrogen fixation and fertilizers, Which nitrogen fixing plants are best /

Q. I’d like to plant a few manageable nitrogen fixing plants and go about fertilization without chemicals, if possible.  Can you recommend any?   A. There is a misunderstanding in the general horticulture community about what nitrogen fixing plants can and can’t do. Nitrogen fixing plants, those plants which can take nitrogen from the air and convert it to nitrogen that a plant can use, do not produce enough nitrogen to support other plants nutritionally that most gardeners might be comfortable with. If you are looking for a trickle of nitrogen to your trees, then perhaps selecting the right nitrogen fixing plant might provide some benefit to your trees. But most nitrogen fixing crops or plants actually require additional applications of nitrogen to perform at its higher levels of production. Nitrogen fixing plants, in my opinion, give the greatest benefit in what we call it green manure crop. These are plants that are grown to a certain stage of maturity and then recycled back into the soil. These plants take nitrogen from the air and also nitrogen from the soil and put it into a form that can slowly decompose. The decomposition of nitrogen fixing plants in soils allow the nitrogen that they have fixed from the air and the soil and converted into forms that slowly release this fertilizer over time. So another words, they take nitrogen that would otherwise might be lost in the environment and give crops a better chance of utilizing it. If you are a permaculturist or a gardener who puts more value into sustainability than the appearance or total production of their garden, then you might be able to appreciate what some of these nitrogen fixing plants can do for trees. But if you are expecting to have a level of production and visual quality of fruit that you could buy from a grocery store or a farmers market, you will probably be disappointed. This does not mean that the fruit will not taste good or it will have a decreased level of nutrients. In fact, the opposite might occur in some fruits but you should not expect the level of production to compete with neighbors who are growing organically or conventionally. I have attached a link from New Mexico State University that talks a little bit about this. http://aces.nmsu.edu/pubs/_a/A129/

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Kumquat Not Producing Fruit

1 Comment / lack of fruit, no fruit on my kumquat why, reasons for no fruit, Why does my kumquat not produce fruit /

Q. Attached is a picture of my Kumquat tree.  I apologize for the picture as there is a lot of other shrubs around the tree making it hard to get a good picture of the tree.  It has been planted for approximately three years and is 5-6 feet tall.  The picture is facing North.  Just within the last year we have had very little fruit whereas prior to that the tree was ample with fruit.  There has been no change to the water schedule (3 days per week for 45 min. each).  The tree appears to be healthy, just no fruit.      Readers kumquat tree The only difference I can think of is that in previous years I covered the tree whenever the temperature was below freezing; however, this past year I only covered it when the temperature fell to the upper 20s.  I think this tree is able to withstand these types of temperatures though.   Any advice you might have would be greatly appreciated. A. Kumquat is a very winter hardy citrus and can survive most winter temperatures here without any problems provided it is in a sheltered spot. It is considered one of the more cold tolerant of the citrus. The key question you have to ask yourself is whether it produced any flowers are not this year. The major reasons for fruit drop are temperature and irrigation problems. If we have freezing temperatures or if the plants become water stressed from not enough water, they tend to drop fruit if it was produced or even flowers. Flower buds and fruits are much less hardy to freezing temperatures than the plant itself. Kumquat may produce fruit all through the year but tend to produce fruit in the spring and fall months and through the winter. If it does get some winter damage, you would’ve seen die back. The plant will regrow to the height it was before it had damage with very few flowers. Once it reestablishes the size of had before, it will then begin to flower again more profusely and produce fruit.  If there were some spring freezes the flower buds would be killed before anything else would show any damage. This would tend to minimize fruit production. If the plant receives a lot of fertilizer, particularly nitrogen, it may tend to put on new growth with few flowers and of course very little if any fruit.

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Peach Leaves Suffer from Black Spots

Leave a Comment / Black spots on peach leaves, peach leaf scorch /

Q. Can you tell me what this is on one of our peach trees? Picture from reader. A. I am looking at your picture now of the peach leaf. It was hard to see what the problem might be with only one picture and that picture was low resolution.  What I saw was one leaf inside the canopy in some shade with some black spots developing on the leaf margins. I couldn’t be certain but it looked like there was a yellow halo around the black spots on the margins.  I don’t know if this is typical of all the leaves or just the leaves in the shade. For me there were two possibilities; irrigation or a disease called shot hole fungus or Coryneum Blight.  If it was over the entire canopy and it involves leaves in full sunlight then I would tend to think it was irrigation related. It usually occurs if the tree is not getting enough water at the time of an irrigation or if you waited too long between irrigations. If the tree has gotten considerably larger in the last two years than I would add any emitter or two to the irrigation of the tree. I would also mulch the surface of the soil to conserve water and reduce water stress. If this is Coryneum blight then you would spray the tree with a copper-based fungicide such as Bordeaux mixture immediately when the leaves fall from the tree this early winter. You would follow up with the spray in the spring as the leaves are coming out and new growth is emerging but after blooming has finished.

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Solar Festival Event in Las Vegas

Leave a Comment / how much do solar panels cost, should I use solar energy, solar energy, solar energy education, Solar panels /

SOLARBRATION!  A free solar festival Local group invites the community to the third annual solar festival LAS VEGAS, Nev. – The Conservation District of Southern Nevada invites the community to attend the third Annual Solarbration solar festival which will be held Saturday, October 11, 2014 at the University of Nevada Cooperative Extension’s Lifelong Learning Center from noon to 4 p.m. The purpose of the festival is to blend art, technology and outreach to promote renewable energy, inspire conservation, and support sustainable communities.  The Solarbration festival will offer the community the opportunity to enjoy solar-powered art, live music, food and fun.  Plus, there will be solar demonstrations and the latest information on sustainable energy. “We promise to deliver a fun-filled family event that will be a one-stop location for everything related to going solar,” said Jon Wardlaw, Commission Chairman of the Conservation District of Southern Nevada.  “We will have all the latest information regarding energy rebates, tax credits, solar financing, and lots of hands-on activities for all ages.” Like last year, the event will be “bike friendly” and promises to be even more fun and activity-packed than last year. The Lifelong Learning Center is located at 8050 Paradise Road, Las Vegas, Nev. (I-215 and Windmill Lane) right near the Clark County 215 trail.  Bike clubs are encouraged to make a ride out of the event.  Solar Village You won’t want to miss The Solar Village where visitors will have a chance to meet over 35 exhibitors, with selected presentations on solar living, electric cars and more plus have the opportunity to get answers to questions about solar energy, and find out how they can install solar on their home or business. Plus there will be hands-on fun activities for children.  There will be solar art projects, fun in the sun games and make-and-take solar nightlights to name a few of the many and varied activities.  And the Food Trucks and live bands will be there so the evening will be complete with great food as well. Whether you are looking for information on solar financing, the Solar Generations rebate program, Federal rebates, energy efficient home improvements, or energy star appliances, the Solar Festival will be your one-stop resource center. The wide range of exhibitors will include solar and renewable energy companies, green home builders, sustainable home products, and hybrid and electric vehicles. The event will be free to the public and all ages are welcome. Proceeds will go to commission a solar powered public art project to be enjoyed as our community continues to celebrate solar energy.  For more information visit http://www.cdsn.org/events/solarbration.html or like the Solar Festival – Las Vegas page on Facebook.

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Cut Back Amaryllis When Leaves Turn Brown

Leave a Comment / brown leaves, first Frost, When do you cut back Amaryllis /

Q. What do I do with my 4 foot high amaryllis plants?  How much should I cut them back? What is Amaryllis? A.Amaryllis is a perennial flowering plant that comes from an underground bulb, much like a tulip. At 4 feet tall,yours is a large one. The size may vary with a variety and light exposure. If they are not getting enough light the leaves will be very succulent. With adequate light believes should be leathery and more durable.              Amaryllis is a fun plant to grow in the desert provided you amend the soil with compost and cover the soil surrounding it with an organic mulch such as wood chips that decompose and continue to improve the soil.Make sure you keep it away from late afternoon sun. You have your amaryllis in good exposure it sounds like with it in the East side with some filtered light during part of the day. Amaryllis does well with half-day sunlight. As you’ve already expressed I’m sure that you amended your soil with compost the time of planting and mulched the bulbs. Sometimes the flowers need staking because they can get a little top-heavy. They will die back at the first frost. At this time feel free to cut them back to the ground. Cover the bulbs with 4 to 6 inches of wood mulch through the coldest part of the winter. When all danger of frost has passed go ahead and uncover them and let them warm up. I would fertilize lightly once a month. You can buy Amaryllis in many of the stores like Home Depot and Lowe’s while they are in bloom. Enjoy them in your home while they are blooming and then transfer them outside and plant them in the ground or in a container. And planting them in the correct soil are both important with this plant. If you plant them in shade you might be disappointed when they don’t bloom the way they are supposed to. They need light but they should receive light during the cooler parts of the day and protected from sunlight when it is very hot. This means the Eastern or northern exposures are best as long as they avoid the late afternoon sun. Planting under trees that provide filtered light, but not dense shade, will also work. Soil improvement is extremely important. When you are planting make sure you add at least 50% compost to a desert soil. Soil amendments decides compost should include all meal or a high phosphorus fertilizer at the time of planting and mixed with the compost/soil mixture. You might need to stake the flower stalk at the time of planting if you fear wind damage. Use a thin bamboo stake and green nursery tape. As with any flowering plants in the garden, fertilize this plant with a good fertilizer for flowering like you might use for roses or gardenias. Fertilize them once a month lightly during their growing season. Amaryllis can also be used as a cut flower inside the home. More information on Amaryllis from the National Arboretum You will have to adapt this information to our climate.

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