Xtremehorticulture

There is Lots of Salt in Las Vegas Water and It Can Affect Plants

Q. I saw that on August 12th you responded to a question regarding yellowing leaves on a Meyer lemon tree.  My tree has similar symptoms – though the yellowing is more spotty and on tips.  You advised to “give it a long deep watering about once every few weeks…to supplement the regular water to leach out the salts…” (emphasis added).             I realize that soil make-up effects watering needs, but can you give me a ballpark as to how many gallons of  “regular water” per week is needed for these trees in Las Vegas in addition to the leaching you recommended?  My tree is approximately 7 feet tall. Should I spread these gallons out over a few days a week, or is giving it these gallons slowing on a single day once a week? A. That’s actually a very interesting question and we have some research to back up the amount. There is about one ton of different kinds of salts (all of these together make up the “salt” content) in one acre foot of water that comes from the Colorado River (Lake Mead).  Rose leaf with salt damage             An acre foot of water is about 360,000 gallons. Unless you are on a well, this represents about 80% of the drinking and irrigation water provided by water purveyors (Las Vegas Valley Water District in the case of Las Vegas) in the Las Vegas Valley.             This sounds like it could be quite dilute but actually when you water to a lawn from Lake Mead it will carry 4/5 ton of salt for every 360,000 gallons that are applied. This translates to an application of 800 pounds of salt for every 1000 square feet of lawn area each year. Salt damage to pineapple guava from salt in the irrigation water             Bottom line, if this is municipal water it carries a considerable amount of salt. If you skimp on the amount of water that you apply and don’t overwater a little bit, this salt will accumulate around the roots of plants. This “little bit” of overwatering each time you water is only about 15%.             So if you apply 100 gallons you really should apply 115 gallons to help move the salts out of the root zone of plants. If it is 50 gallons, then apply an extra 7.5 gallons. Ten gallons means you should apply 11.5 gallons.             Few people are this precise when they water unless they are watering a golf course and paying $1M each year to irrigate an 18 hole golf course. So when you water you can apply a little bit extra each time you water (15%) or you can flush out the salts around the roots by adding an extra irrigation or two during the hot months to keep those salts moving out. I hope this helps.

There is Lots of Salt in Las Vegas Water and It Can Affect Plants Read More »

Where to Get Pheremone Traps

Delta trap with pheremone inside Q. Do you know where I can get pheromone traps for insects that cause damage in our area and also for thrips that damage nectarines? A. Try Peaceful Valley at http://www.groworganic.com/weed-pest-control/organic-pest-control/insect-lure.html             Pheremone traps can be used to identify what insect problems you have in your backyard orchard and when to spray. Commonly we use them for peaches, nectarines, apples and pears. You will want a trap for each insect and about three or four lures for each trap since they have to be replaced regularly. You will replace the lures about every 4 to 5 weeks until harvest then you can stop. Wing trap with pheremone inside             There are no traps for thrips. For thrips you will need Spinosad biological insecticide which you can get from local nurseries. The label may not say spinosad but may say something like borer, bagworm control. You may have to look at the ingredients to see the spinosad.

Where to Get Pheremone Traps Read More »

Must Cut the Roots of Italian Cypress to Put in a Block Wall

Q. We are thinking of taking out our wooden fence and replacing it with cinder-block wall.  The Italian cypress trees grow along 2 sections of the fence and are about 20 years old.  The new block fence will go on the other side of the wooden fence but there’s the footing to consider which will cut into the root system.  My question to you is, what are the chances of these trees surviving since we won’t know how much of the root will be cut into?  I can send pictures of the base of the tree with the irrigation and the existing fence post to give you a better picture of the area or I can send measurements of what I am planning.  Not sure if the pictures will give you enough detail to make an informed prediction.  This is a picture of the soil around some oleanders after a block wall had been removed and was being replaced. This is not the readers but a friends. The oleanders were being watered in a shrub bed with bubblers. Notice that there is not alot of root development next to the wall. As you know the trimming of these trees are time consuming and/or expensive to hire out.  We wonder if the block wall will bring more heat to the yard and could the heat from the wall burn the tree?   The reason we are considering this project is that with our dogs we are simply worried that if a plank snaps that our dogs will get out and possibly hurt.  We like to rustic look of the wooden fence but we wonder if the block wall might be a better choice for security.  Any thoughts on your part would be appreciated.   A. Let me talk about things I know something about, the damage to the trees if you decide to move ahead with a block wall, replacing a wooden fence.     In the desert, plants grow where there is adequate water. If a good supply of water is on your side of the fence, the roots will tend to grow more in that direction. If there is lots of water on the other side of the fence, they may tend to grow in that direction.  Notice the difference between the shallow fleshy roots of the palm tree (left) and the oleanders on the right. Palm roots grow where there is more air, near the wall.     So try to picture that your tree’s roots will grow more in the presence of water. Would this be on your side of the wall or your neighbor’s side? So if a cinder block wall is constucted, a trench will be dug and a footer laid to support this very heavy wall. You are right, this will definitely eliminate a portion of their root system.    If these tree’s roots are growing toward your neighbor mostly, then these trees will suffer significant damage. If your landscape is dry and the neighbor’s is wet, this might cause severe damage to your trees.     If their water is coming mostly from your yard and your neighbor’s is dry, hen cutting the roots on the side toward your neighbor will probably have a more minimal effect. This picture from Washington State University shows how some plant roots will grow toward a good balance of air and water such as close to the container wall.     Likewise if their water is coming from a water source in small amounts from drip irrigation close to the trunk adn the resest of the yard is dry then the impact will probably  be minimal. In other words,if you are trenching in soil that stays dry for most of the year you will probably be okay.     Another word of caution. The week before they put in the footer water the trees very well. Then let the soil dry out until they dig. Encourage them to dig, put the footer in and backfill the soil as soon as possible to minimize damage to the trees. As soon as possible, irrigate the trees again.

Must Cut the Roots of Italian Cypress to Put in a Block Wall Read More »

What Kind of Grass Do I Have?

 If you see this on your sidewalk you have common bermudagrass either as a weed or as a lawn grass. Q. We moved here last year and have not ever had the experience with the type of grass that is in our back yard. My husband says we need a four wheel drive lawn mower for mowing, extremely bumpy and patchy. What kind of grass seed should we be using here for this environment, and when to re-seed? Thank you and the Gazenias you advised me to plant and thick and healthy!! A. It will be tough to tell but the two common grasses here are fescue (a bunching grass which might be giving you all the bumps) and bermudagrass. Bermudagrass runs along the ground and is flat. The bermudagrass, if that is one you have, will turn brown this late fall and early winter (November/December). If you have a mixture of the two then you will see the parts of the lawn with bermuda turn brown this winter and the tall fescue will stay green in clumps. If you do have a mixture it is usually because of an inadequate irrigation system or not very good irrigation practices. The bermudagrass can survive with lots less water than the fescue. So when water is limited, the bermudagrass takes over those areas. From left to right upper leaf surface of Kentucky bluegrass, perennial ryegrass and tall fescue. Actually the tall fescue leaf surface could also pass for annual ryegrass. It is easy to spray and kill the fescue during the winter in the bermudagrass (beremudagrass is brown then and sleeping and will not get hurt) with Roundup but not the other way around. But most people do not like a bermudagrass lawn. Hope this helps.

What Kind of Grass Do I Have? Read More »

Overseeding Bermudagrass With a Winter Grass

Q. My backyard has a bermudagrass lawn and I would like to overseed with a winter ryegrass seed. When I have done this before, I “burned out” the bermuda by not watering it, then rented a power rake to de-thatch it. This year with all the rain, my bermuda is not turning brown. My concern is if the lawn is green the power rake will not remove the thatch. Also, which do you recommend annual or perennial rye seed and why? Dethatcher or verical mower. A. Overseeding bermudagrass with a cool season grass like one of the ryegrasses has a window of time which is optimum in the fall. This window is from September 15 to October 15. If you overseed to early, the bermudagrass is too active and will compete with your winter lawn. If you overseed too late, you run the risk that it will get too cold quickly and the overseeded grass may not all germinate and fill in your overseeded area.             The mantra for effective overseeding is having “good soil to seed contact”. In other words, the seed should rest on the soil when you overseed correctly. If the bermudagrass is too dense, much of the seed will not land on the soil and you will have a spotty winter lawn. Common Bermudagrass stolon             Sounds like you have the correct sequence for overseeding; time the overseed around October 1, September 15 turn off the water to the bermudagrass, September 21 mow as short as possible (rotary mower on the lowest setting is fine), power rake or dethatch until you see bare soil, apply seed, fertilizer, topdress the seed and fertilizer and water.             Bermudagrass lawns are usually mowed somewhere from ½ to 1 inch high. I like to let it grow to an 1½ in August/September. This produces more stem so I can “scalp” it better and get the seed to fall onto the soil for that good soil/seed contact.             You can use annual ryegrass if you want but it is coarse textured, light green and rough to the touch. Perennial ryegrass is a much prettier grass and soft to the touch. You can put all the nitrogen you want on annual ryegrass and it will just not get the same dark green color as perennial ryegrass. It is more expensive but will give you a much prettier lawn.

Overseeding Bermudagrass With a Winter Grass Read More »

Vine in Lawn Turns Out To Be Bermudagrass

Q. I found this vine growing in my lawn and sent you pictures of it.  I tried treating it with Ortho’s Weed Be Gone.  As of this morning I still have the vine.  Do you have any idea what it may be and how I can treat it or get rid of it? Vine in lawn appears to be bermudagrass or Devil grass. A. From the look of this “vine”, it appears to be bermudagrass. Some old timers call it Devil grass mostly because it is the devil to get rid of. Once it is in a lawn, it is tough to nearly impossible to get rid of.             It is easier to get rid of if it is in a shrub bed. Then you can cut it back to a foot long (as long as it has leaves) and “spot spray” what’s left with Roundup. Other products that have reasonable success at some control include Poast and Fusilade which can be used fairly safely among shrubs and groundcovers.             Bermudagrass gets in a lawn usually if the lawn begins to “thin” or lose its density. This is because it is not kept full and dense. This can be because it is not fertilized regularly, mowed too short or an insect or disease problem.             Mowing too short can occur by lowering your mower too close to the ground or by using a line trimmer and whacking the grass low around sprinkler heads or along the edge of the lawn to make it look pretty.             The best defense is a good offense. Keep the lawn at 2 to 2 1/2 inches if it is fescue. Keep it fertilized regularly. If patches of the lawn die, do not disturb the dead area and/or reseed or resod until mid to late September when bermudagrass is going to sleep.

Vine in Lawn Turns Out To Be Bermudagrass Read More »

Bay Leaves Browning and Yellowing

Q. I have several bay leaf bushes but one appears to be dying.  What can I do, if anything, to nurse it back to health? A. Two things are going to be a problem for you, maybe three. First, judging from your picture, it is in rock mulch. This plant will not handle a rock mulch environment very well. If it is going to work for you in rock then it should be in an eastern exposure where the wall would be to its west. Picture will not insert properly in Blogspot. Bay Leaf of reader.             If your plant is in this environment then it might be getting hammered by being fully exposed to the southern sun as well. It will do much better with some protection from that hot, blazing sun in the summer. That is why you are seeing the leaves with brown tips and edges.             Secondly is the yellow color developing on the new leaves, leaves at the ends of the branches. Most likely this is a nutrient deficiency due to the poor nutrient capacity of that desert soil. Rock mulch adds nothing to a desert soil. It needs a more fertile soil and should not be planted like it is growing in the middle of a desert somewhere.             Thirdly, you might have trouble keeping it through the winters here. It is not terribly tolerant of real low winter temperatures. If it is in the open and can get hit by cold winter winds then it may freeze back yearly or every few years when we hit a good cold spell.             I would move it to a new location this fall, about mid-September to October. Move it somewhere where the sun won’t hammer it after noon or two PM. Heavily compost the soil when you plant it. Use organic mulch around it, not rock mulch. Put it somewhere the plant will be protected from freezing winter winds. Hope this helps.

Bay Leaves Browning and Yellowing Read More »

Lack of Fullness in Japanese Blueberry

Q. I was referred to you by Lori, a Master Gardener re: my problem with my Japanese Blueberry trees. I have planted 3  in November 2009, they are about 7 ft tall, 4 ft wide, trunk column about 3 inches in diameter . Leaves seemed to fall prematurely, browning and yellowish. One of the trees bark is peeling off and appeared to be dry. I have 3 sprinkler tubes on each tree, dripping 1 gl/hr each (I think). There’s no visible insects but I do not know what to find anyway. Leaves seemed scarce, does not have that fullness that other trees does.  I have not sprayed them anything, no fertilizer or some sort. I put some manure compost 2 months ago. I am a novice on gardening so my description might seem funny. I can send some pictures if that would help. I have spent so much money on them for them to die. Please help. Japanese blueberry along a block wall in rock mulch A. Japanese blueberries will require a soil that is a composted at the time of planting and an organic mulch on the surface of the soil after planting.  It will do terribly in south or western exposures in full sun or in rock mulches.  If you planted this Japanese blueberry from a 15 gallon container then it will require about 15 gallons of water each time you water.   The amount of water must increase from this amount as the plant gets larger from year to year.  This can be accomplished by adding minutes to your existing irrigation schedule at each watering or adding additional emitters.  If these are 1 gallon per hour emitters and there are three of them then the irrigation run time for this tree should be somewhere around 5 hours for it to get adequate water.   Water requirement curve for the Las Vegas area. The first bar (1) is January and the last bar is December (12). You can see that water demand by plants increases 400% from January to July and August. Unless this plant is getting water from other sources it will be under watered if you are irrigating for only one are 2 hours.  The frequency of application of the water, but not the number of gallons per application, will vary from season to season.  There is generally are a winter schedule, spring schedule, summer schedule, fall schedule and back too a winter schedule which means you should increase the number of times you irrigate per week about four times each year.   These schedules will coincide approximately with December 1, February 1, May 1, mid June, mid September and finally December 1 which completes the seasonal cycle.   Because your plant does not have the fullness that caught your eye I would assume it is due to improper irrigation which may have led to infestation with borers.  Pull off the loose bark at you see and look for damage in the wood do too boring insects.  This would include sawdust under the bark and perhaps elliptical exit holes from the trunk under the damaged area.  If the damage is more than half way around the trunk then I would replace the plant.

Lack of Fullness in Japanese Blueberry Read More »

Yellowing on Meyer Lemon Might Be Magnesium Deficiency

Meyer Lemon with deficiency Q. We have went to the nursery a couple times about this tree. First we got the water cycle correct, then iron was suggested which we did as they directed then Gold Dust was suggested. Online I read possibly the tree suffers from a magnesium issue. I thought these photos would give a better picture. All we did as directed and the tree is not responding in fact it is getting worse. I am wondering if it is because of where it was planted which is a confined root growing area. Any insight would be appreciated. Meyer lemon another shot. A. By looking at the leaves I have to assume this is a Meyer Lemon (which is, by the way not technically a lemon but an unknown hybrid found in a Chinese back yard by USDA researcher D. Meyer in the early 20th century). Your pictures are all pretty good with the exception of not showing a critical view of the trunk where it is just out of the soil. Just for future reference always look at and show this interface of the trunk and soil. W/o that view I have to only guess that the rootstock/trunk union is well out of the soil and we can eliminate that issue. And, a shot of the soil might show how the plant is getting watered. I have to assume drippers and I would guess they are in the same locations as when the plant was planted. The leaves show two distinctive symptoms that often occur in concert: 1. There is some salt burn and 2. The common symptom that comes with salt issues is the magnesium deficiency. Just FYI Iron def. only occurs on the new leaves. For the salinity (salt) issue we usually look first at the watering and with watering comes knowing if the water can even be applied uniformly all around the edge of the canopy, sometimes called the ‘drip line’. Citrus are botanically a shrub with shallow and wide spreading roots that are tough to grow to maturity with drippers unless they are closely spaced in a wide band around the canopy’s edge. There is one picture showing the plant is right next to a step wall with no water being applied in that zone of the root system. I would not worry too much about adding any supplements and see if you can begin to manage a watering system of application that would give a long deep soaking water application out near the drip line. The ‘soaker’ hoses could be laid out on the ground out near the drip line and let it run for hours and hours to try and leach out the excess salts that may have accumulated over time with the drip system. Drip systems are fine but, due to their limited water output salts can begin to accumulate thus impacting citrus’ sensitivity to salts. Give it a long deep watering about once every few weeks from now on all during the growing season (May through October)  to supplement the regular water to leach out the salts that inevitably are deposited with the limited volume of drip systems . .This leaching watering is also the great time to add fertilizer and get it into the soil evenly all around the active roots near the drip line. Terry Mikel

Yellowing on Meyer Lemon Might Be Magnesium Deficiency Read More »

Gardener Moving to Las Vegas from San Francisco

Q. My husband found your site. We are facing the possibility of a move to Las Vegas. We have never lived in a desert climate. I am hoping to continue my love of gardening with vegetables, flowers, and a water garden like I have here in the San Francisco Bay Area. My biggest problems here have been raccoons, squirrels, aphids, and powdery mildew. Will any of those be things I will face in Vegas? What are the biggest pests/problems I should prepare for? (I’m praying you don’t say scorpions or fire ants!)             Also, my great love is dahlias. I have about 44 plants here, though ironically our summer was so cool that it was a poor year for us (our tomatoes were also a disappointment, and I sure hope that won’t be the case in LV). How well to dahlias fare in Vegas, and will they bloom at a different time of year? Should I consider putting them in double pots and not in the ground (we’ve talked about raised beds with high quality soil)? Someone told me that grasshoppers are so bad there that I will need to completely fence in the whole garden area with small mesh wire to block the bugs out, is this true? What are your thoughts?             I realize this letter contains a lot of questions… but any help you can give a life-long gardener or who very nervous she will have to give up all the plants she loves would be greatly appreciated A. Well Shannon… we do have bark scorpions but we don’t have very many fire ants. Those are pretty rare and relatively easy to control so far. So take a deep breath… it’s not so bad. The desert can be beautiful.             No raccoons in the Las Vegas area. No grey squirrels but we do have ground squirrels which some call chipmunks which they aren’t but they do look a little like Chip and Dale. They can be pesky.             We do have some aphids in the spring but they disappear when it gets hot. Powdery mildew is relatively rare compared to San Francisco. Dahlias will be tough for you in Las Vegas. We can produce some wonderful vegetables and fruits here and you will find them rivaling in quality to what you can find at the Farmers Markets in San Francisco. Ground squirrel             Now the bad news. This is the desert. Growing things here will be NOTHING like what you are familiar with. You will have to relearn your gardening skills and adapt them to the desert climate. Your new mantra will be compost, compost, compost. And everything will revolve around water.             Yes, you have a lot to learn but think of it as an adventure and your gardening skills will be tested here. No “throw a seed in the ground and watch it grow” here. Thats why I am here. Feel free to ask. By the way, the grasshopper story is totally far-fetched. You will need a shotgun. (Just kidding, it is not that bad ……… most years) 🙂 Maybe some others here can give you some pointers.

Gardener Moving to Las Vegas from San Francisco Read More »