Xtremehorticulture

Xtremehorticulture of the Desert

Deformed Lilac Leaves Maybe a Sign of Problems

Leave a Comment / lilac crinkled leaves, lilac cupped leaves /

Q. My lilac bush had some leaves on it that suddenly look like they are deformed. What is the problem? A. Deformed or crinkled leaves can indicate several things. If the edges of the leaves were damaged, scorched, the interior of the leaf will continue to grow while the dead margin will not. This can cause leaf deformity called cupping. Stink bug Feeding damage by some bugs on leaf buds before they open can cause crinkled or deformed leaves. These include the stink bug group of insects such as the leaf footed plant bugs. Look for bugs on the bottom of the leaves or crawling on stems. Leaf deformity can be caused by “weed killer” sprays that drifted on the foliage during windy or hot weather. Some herbicides, like dandelion killers for lawns, cause leaf deformity if it comes in contact with leaves as they are enlarging or expanding. Squash bugs, one of the stink bug types Bottom line, most likely the damage is temporary and as more leaves develop they should be normal. However, if you inspect the plant and see these types of insects apply an insecticide for ornamental plants and spray leaves and stems during early morning hours. Spray the undersides of leaves because this is where most the bugs hang out. Make sure the plant gets enough water. This is a plant that likes compost and wood mulch, not rock mulch. Lilacs do not like rocks covering the surface of the soil. Every year apply 1/2 cubic foot of compost on top of the mulch and water it in. Use a high phosphorus fertilizer that promotes flowering of woody plants.

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Mildew on Roses Have Common Link

2 Comments / powdery mildew of rose /

Q. My roses are covered with mildew.  I have sprayed them and hope they will recover.  I have not had this problem in years.  What causes mildew and how do you keep it from coming back? Powdery mildew of roses, severe A. Diseases develop on plants when the environment is just right for that disease, disease organisms come in contact with the plant and the plant must be susceptible to it. Let’s break each of these factors down. Remember, when dealing with diseases it is most important to prevent diseases from happening rather than cure them with a pesticide after the fact. Powdery mildew of roses, or powdery mildew of any plant for that matter, develops best in shady spots during cooler times of the year and when it is moist. It does not like to develop in full sun and when it is hot and dry. We see powdery mildew during cool weather of spring and fall and times just after it rains. It is common when roses are grown in shady spots and watered with sprinklers. Powdery mildew of weeds Powdery mildew can be spread by splashing water. This can be from rain or sprinklers. It can also be spread by hands, pruning shears and wind. Powdery mildew likes some roses better than others. The variety of rose and how healthy it is has a lot to do with how often you will see powdery mildew on it. So if you want powdery mildew on roses then grow a variety susceptible to powdery mildew, don’t fertilize it very often, prune it incorrectly, place it in the shade and water it with sprinklers. The flip side is best for disease free roses: select a variety resistant to powdery mildew, plant it in at least 6 to 8 hours of full sun each day, apply compost and wood mulch to the soil, keep it healthy with at least one application of a rose fertilizer every year and irrigate using drip irrigation. These links may help you with some general information on powdery mildew. http://xtremehorticulture.blogspot.com/2014/12/euonymus-plants-have-white-spots-and.html http://xtremehorticulture.blogspot.com/2015/01/pick-right-variety-of-roses-for-desert.html

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Hugelkulter Mound in the Desert?

8 Comments / Hugelkulter, permaculture /

Q. I have been reading about building a Hugelkulter mound. My husband and I are in our 60’s and the less we have to be on our knees the better it is for our backs. I wonder if we could build a Hugelkulter mound out of desert materials? Every article I’ve read seems to be in a forested area where wood is readily available. A. I have to be honest with you. I have never heard of this before so I had to do some digging (not literally) into the subject. I also have to admit I don’t know anything about it but I did find someone to refer you to. I met her a couple of weeks ago at a class I was teaching in Arizona. Hugelkulter on Wikipedia She is a permaculture advocate and a delightful person. I have not visited her place in Arizona but she is enthusiastic and someone I would recommend you contact for more information. Christine Baker 928-564-2642 [email protected] www.highdesertpermaculture.org Perhaps there are others out there who can chime in. Let’s all remember this IS the Mojave Desert.

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Fuzz Balls on Oak Leaves Damage

Leave a Comment / cotton balls on leaves, leaf balls on Heritage live oak, What causes leaf galls /

Q. I found these fuzzy things on my oak leaves. What are they and should I be concerned? Oak leaf gall caused by  tiny wasp A. These fall under the general category of plant galls. Galls are swellings of plant tissue and located on the roots, stems, trunk, leaves and flowers. Galls can be caused by insects, diseases, nematodes or mites. This particular gall is on the leaf of oak, and my guess it is ‘Heritage’ live oak. These leaf galls are very common to oak and caused by a tiny wasp. The purpose of the gall is to protect the developing youngster until it is mature and exits the gall to find a mate. Later on in the season you will see a small exit hole and the gall will probably turn brown or the leaf may turn brown and drop from the tree if the infestation is quite severe. Ash flower gall caused by eriophyid mites feeding on flower buds The basic lifecycle is for the female to lay an egg inside the leaf or on a leaf surface. The egg hatches and the very tiny larva eats the plant tissue inside the leaf. It also releases chemicals that control the growth of the leaf around the area where it is feeding. This disturbed area grows in response to the feeding and causes the leaf to grow into a tumor-like growth totally surrounding the youngster. Inside this gall the youngster can continue to feed protected from predators and the environment. Eventually the youngster grows up into an adult and exits the gall in pursuit of a mate. Once the mate is found, the life cycle repeats itself. In some cases a large number of these wasps can exit numerous galls and build a large population that can cause leaf drop. These leaf galls normally don’t present a problem and I would just ignore them. However if they do create a problem you might consider applying a tree systemic insecticide to the soil surrounding the tree near the source of irrigation water. I would apply it as soon as you see leaf galls developing in the spring. A picture of this same oak gall appears at this website by Armstrong with a short description along with a bunch of other galls. http://waynesword.palomar.edu/pljuly99.htm#insects You can learn more about plant galls by visiting this website located at Brandeis University. http://www.bio.brandeis.edu/fieldbio/Plant_Galls/samplepage.html Leaf drop could also occur from excessive shade and a lack of water or applying water too often. You should not be watering daily. All it takes is one or two missed irrigations and you could have leaf drop from a lack of water during hot, dry weather. Watering too often would cause root rots and leaf drop and a sudden death of the tree during hot weather. Applying a heavy dose of nitrogen fertilizer close to the trunk could also cause leaf drop and possible tree damage.

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No Water? No Vine.

Leave a Comment / plants that survive without irrigation, Vine that will survive without water /

Q. Is there any decorative vine which will prosper in Southern Nevada with no irrigation at all except what nature provides? The situation is the bare-looking north side of a wall where I do not want to extend irrigation piping. A. There is no vine that will make it here without additional irrigation. We average 4 inches of water each year. I have seen it without rain here for over one year. That irrigation might come from a neighbor but it will not survive without some source of water. We do have wild grape and some other vines that do grow along waterways coming from mountain runoff but they have water and grape roots can grow to depths of 30 or more feet. The key to avoiding a lack of water is to either store the water in modified plant parts like cactus or have very deep roots that can tap into a water supply that we cannot see.

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Microclimates Have Profound Effects on Gardens

Leave a Comment / where should I locate my garden, where should I put my raised beds /

Q. I live in North Las Vegas and am considering a vegetable garden in my backyard when I retire in January of ’16.  I have adequate space on east or west side of the house.  However, the west side has a high wall that blocks off the afternoon sun. Which side would be best for the garden? Shade can have a dramatic effect on the temperature/humidity/light microclimate of a yard. A. I think of growing areas in the yard in terms of microclimates. It sounds like you may have two different microclimates going on; the warmer but shadier west side and the cooler east side. I would consider having growing beds on both sides if they are significantly different in their environments. These two different microclimates can extend your production by a couple of weeks or more in the spring and fall; earlier spring and later fall production in the hotter microclimate and later spring and earlier fall production in the cooler one. Reflected light also counts as light that the benefits plants as long as it is bright enough. I would not discount the west area simply because you have a wall on the west side. I would consider painting these walls to reflect more light or cover their surfaces for the same reason. Think back when you have been in both of those areas and your impressions regarding their different microclimates. Was one microclimate quite a bit different in seasonal temperatures than the other? If these microclimates are so similar you do not get any advantage then I would put it on the east side. 

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Barrel Cactus Problems Tied to Water

Leave a Comment / cacti, how to water barrel cactus, why is my barrel cactus dying /

Q. Over the years I planted perhaps 10 different golden barrel cacti. Nearly all died the same way. I first notice a hole in the main body of the plant. It looks like a rodent gnawed the hole. I have never found anything inside the plant. The plant retains its color and appears healthy. After about a year the root system is gone and I remove the plant. Can you explain? Golden barrel cactus with pups A. When I lose a barrel cactus that way and the hole is at the bottom of the plant it is usually from poor soil drainage and watering too often. The roots rot as well as the interior. Reduce the frequency of your watering and make sure the soil drains extremely well.             If you catch the problem early enough you can arrest the damage by shutting off the water until the plant recovers. After that, water less often. If they are watered more than once every two weeks this might be the problem. They rely on storage water during times of water shortages. The size of the plant increases after a heavy rain and decreases when water is scarce because of the stored water. The only creature that I would think might be interested in barrel cactus and might be able to damage them are ground squirrels. But they usually harvest fruits from them, not the fleshy interior.

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