Xtremehorticulture

Drip Emitters Can Plug Easily If You Are Not Careful

Pvc glue plugging an irrigation bubbler after a repair Q. A few years ago I had a bubbler system installed to water my trees for my desert landscaping. They did not do a good great job. It has gotten plugged a few times and the trees do not get enough water. I have gone through four trees and maybe another. Would you give me some names of trees that are truly drought resistant? A. I hesitate giving you suggestions on plants because that is a highly subjective decision and secondly without a reliable irrigation system nothing will work in our desert except maybe Joshua trees. Besides, in our desert there are no ornamental and shade trees that will survive or look good without a good irrigation system. Y filter for drip irrigation  Salt accumulation on a drip emitter  Make sure your irrigation system has a 150 to 200 mesh filter installed somewhere before the water reaches the emitters. This will reduce plugging. Make sure that when you or anyone repairs a drip system that they DO NOT use a pipe cutting device that rips the piping. So do not use a hacksaw or other pipe cutter that uses teeth to rip at the pipe. This will leave pipe debris in the lines that will (guaranteed) plug your emitters. PVC cutter that does not leave debris in the pipes Use only a cutting device that has an unserrated knife edge that cuts the piping. Use pipe cutters instead. They are more expensive but will actually work quite well. I don’t care how careful you think you are, don’t use devices that rip or shred on any part of a drip system. Once you have a reliable irrigation system then you can plant some good stuff.

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Lawns Brown Spots Can Be Dogs and Poor Sprinkler Coverage

Dog urine damage leaves a dark green edge around the damaged brown spot caused by the urine Most likely there is a popup sprinkler in the center of that green patch surrounded by bare soil. It is most likely a two inch popup when a four inch is needed in tall fescue Q. My lawn was sodded with tall fescue lawn grass a few years back and this past fall noticed I still have two problems. The pictures attached. The first are five to ten inch circles which are brown in the center with very dark green grass around it. The second are areas around the edge where there is a patch of dark green grass and then 10-15 inches of bare ground around it. I am really hoping you can provide an explanation and solution to resolve these. A. The third picture, brown ten inch circles with dark green on the outside, looks like damage from a urinating dog. Urine results in a small round brown area where the grass is darker green around the dead spot. Readers can see these pictures by following my blog at http://www.xtremehorticulture.blogspot.com/ Popup sprinklers need clearance over the grass if they are going to cover the lawn area evenly The urine is too high in salts (urea, a salt high in nitrogen) and burns the immediate area around where it is applied. As the urea moves into the surrounding soil it becomes more dilute, reducing the burning, and then acts like a fertilizer high in nitrogen. Nitrogen fertilizers turn grass a dark green. The other picture with 10 to 15 inches of bare ground around a green area, looks like the sprinkler head is in the center of that small green area next to the curb. If that is the case, I am guessing the popup is not “popping” high enough. Make sure it pops up all the way and is not getting blocked. Make sure your irrigation sprinklers are 4 inch and not 2 inch popups. Two inch popups do not pop up high enough to spray evenly above the top of a grass mowed at two inches in height. The grass height interferes with the water spray. Pressure regulator Also check your water pressure. It should be in the 40 to 50 psi range for most popups. If it is a lot higher than this, then your sprinklers are probably “fogging” and not delivering the right sized droplets to get even coverage over the lawn. Install a pressure regulator to drop the water pressure in the appropriate range recommended by the irrigation manufacturer for the sprinklers and nozzles. Your tall fescue does not look very luxurious in general. It would improve from some good lawn management practices. Tall fescue is best if mowed no shorter than 1½ inch, and 2 inches is even better. Use a mulching mower and return the clippings to the lawn; don’t bag them and leave them for the garbage. Roots of turfgrass grow easily into holes punched in the lawn by an aerifier Try aerating the lawn any time of the year and follow this with an application of a good quality lawn fertilizer. If you are returning the clippings to the lawn then fertilize Labor Day, Memorial Day and 4th of July. Be sure you also make an application around Thanksgiving to keep your lawn dark green through the winter months.

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Lack of Cucumbers Leaves Gardener in a Pickle

 Armenian Cucumber  Q. I live in Las Vegas and want to grow baby cucumbers for pickling. I tried to grow some last Spring but was not successful. I didn’t realize until the plants were about 1ft tall that I was supposed to thin them out. I did thin them but it may have been too late. The plants looked good and grew well but when they began to flower, the little tiny cucumbers got very dry and hard and shriveled up. The pot was getting full sun most of the afternoon so my husband built an open lattice over the top for some light shade. As the later part of June approached the plants were not looking good and I gave them up, with the intention of trying again, maybe in the fall when it’s cooler? I was so looking forward to growing and pickling my own. A. Cucumbers have a fairly narrow time for production here as it gets too hot, from about late March or early April to about June. They can suffer from chilling damage if temperatures get below about 50F. You can plant again in September since they have a fairly short production time, about 60 days. Soils should be well composted and fertilized before planting. No lack of water for these plants or you will have problems. Soils must be kept moist so cover the soil with straw mulch or other mulch you can till or spade in afterwards. You will have less waste if you trellis them rather than letting them lay on the soil. In the warm times you will pick three times a week. The easiest to grow is Armenian cucumber but will not make very good pickles. Others to try for pickles might be Eureka and Valispik. Other vegetables and even fruit make great pickles as well.

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Italian Cypress Browning Not a Good Sign

Q. Help! My Italian cypress are drying out and dying mostly from the top down and they have their own bubblers for water. Italian cypress with foliage browning A. Major reasons for Italian cypress dieback: Too much water. Water deeply once 3 – 4 weeks in winter and no more than about once a week in summer. Too little water. Sometimes people put these trees on just a few minutes of water from their drip irrigation system. Water should be applied so that it wets the soil down 24 inches to an area at least four feet in diameter around the tree. Depending on how quickly enough water from your drip system is applied this might take up to several hours of applied water. Spider mites. Starts in hot weather because that’s what they like. Usually a problem on trees that were underwatered. Spider mites like dirty foliage. Wash trees with a high pressure hose nozzle after dust storms or a couple of times a year just to keep them clean. Periodic soap and water sprays are not a bad idea either. Webbing in italian cypress may or may not be due to the bad guys Borers. Several people have reported borers in Italian cypress but this has never been a common occurrence in the past. I could not find it reported anywhere else either. Usually a soil-applied insecticide for borer control applied around the roots would be recommended if this were the case. Get your irrigation under control and that should solve most of the problems.

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Yellowing in Palms Can Be Lots of Different Things

This is California fan palm with cold damage from temperatures in the low 20’s or high teens F Q. We have a fan palm where the palms are turning yellow and I’m assuming dying. One or two would be acceptable but we are have 5 and 6 that are going bad. A. Let’s cover some ideas about why your palms could have yellow fronds. These are the main reasons: older fronds are dying from natural causes and should be removed; fronds were damaged during winter freezes; too much water applied too often or too little water; palms planted too deeply; palms planted in heavy soil that doesn’t drain well; palms planted with pure sand around the rootball; fertilizer problems such as iron, manganese or zinc. Not totally sure on this one but it was probably light cold damage on this date palm during the  winter in low 20’s Palms should be planted with the soil taken from the hole plus 50% compost and a starter fertilizer high in phosphorus added. Palms should NOT be planted with their root ball surrounded by pure sand in the planting hole which is commonly done in Las Vegas. The idea of doing that is absolutely crazy. Palms are high water users even though they tolerate high temperatures and our desert climate. Different types of palms require different amounts of water. The larger the palm, the more water it will require. Some of the highest water users will be date palm with their huge canopy spread. The amount of water will vary but most fan palms would be happy receiving about 20 gallons every time they are irrigated. This is Queen palm, not a good palm for the hot desert and probably lack of soil preparation or watering too often or both One of the common problems is irrigating palm trees with small amounts of water, like ten or fifteen minutes of drip irrigation, daily or even twice a day. Watering like this can fill the soil with water and suffocate the roots causing them to rot, diseased or both. So if you are irrigating your palms daily, don’t do that anymore! During the heat of the summer they can be irrigated two or three times a week, using 20 gallons each time you irrigate but the soil must freely drain the water away from the tree. In the wintertime you might be dropping your irrigation to 20 gallons every 10 days or perhaps even as long as two weeks. Sometimes the soil lacks certain types of minerals that palm trees need. Deficiencies like iron and manganese usually appears as a discoloration in the fronds at the center the canopy, the most recent growth. This can range from light green to nearly yellow. If these inner fronds are yellowing then we can usually narrow this to watering too often, poor drainage or a lack of minor elements such as iron. Center fronds, youngest, demonstrating yellow growth which could be due to watering issues, soil issues or possibly disease Next February when you make your annual application of fertilizer use a complete fertilizer such as a Miracle Gro, Rapid Gro, or Peters. You can also use fertilizer stakes. Make sure it is well balanced and try to select a fertilizer with the three numbers the same or close to the same value like a 16-16-16 or 10-10-10. Add an iron chelate that contains the EDDHA chelate in the ingredients. Let’s see if that works along with irrigating with a large volume of water but doing it less often. Cold damage on palms usually results in the older fronds turning a bronze color first and then browning later as they die. General rule of thumb is if more than half of the frond has turned brown, remove it. The new fronds at the center of the palm should be healthy and green when they emerge in mid-spring. If your soil is heavy and holds water a long time then plant on a mound 2 to 3 feet high and 6 to 8 feet across so the water drains away from the roots.

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Moorpark Apricot a Good One for Las Vegas

Apricots on short shoots called spurs Q. We have a beautiful 5-year old Moorpark apricot tree. It has grown well and looks quite healthy. However, it seems to put out a sparse array of blossoms in spring and has a very light crop of fruit every year. The fruit is delicious. I read that the chill factor for this cultivar may be higher than our climate provides. Can I increase the chill factor by watering the branches in winter on cool days to lower the tree’s temperature and thus increase the chill factor? If successful I could get a larger crop? A. Moorpark is a wonderful apricot variety and is used extensively in the canning and fresh fruit industry in California. It is best if it receives about 600 chill hours during the winter. This means that the temperature should drop below 45F for at least 600 hours for the best fruit set. Apricot branch in the winter with spurs clearly visible However, don’t worry about the chill factor in this case. We have Moorpark and it has good fruit set here even after 18 years at our chill hours. The problem is more likely the fruiting spurs or lack of them. These will be the short branches along the major branches.  If these were pruned off, damaged or never developed then the crop will be light due to a lack of flowers. This year was a bad year for apricots. We had good weather and then it turned very cold in March. That freeze reduced our orchard apricot production from about two tons down to about 200 pounds. We have had no problem with Moorpark and irregular production and it has been a wonderful producer in most years. Perhaps the location of your tree in a particular microclimate of your landscape or how it has been pruned may have more to do with it than the variety itself. But a lack of chilling is not the problem. 

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Zimbabwe and the Baobob Tree

  Hosted at the Bradshaw’s house in Harare. Geoffrey was a fantastic guide in helping me work with local farmers  I went to Zimabwe in August of 2011 to work with some local farmers on some irrigation schemes. They call them irrigation schemes if a group of farmers all use the same source for watering their fields. So for instance if the source of water is a river and there is a diversion from the river (can be a canal or a pump) then everyone getting water from that diversion would be on the same scheme. Sometimes this is a very large main canal and if this main canal is split into two canals and the water can be diverted (forced to go into one or the other but not both at the same time) then each of these would be an irrigation scheme.   Using siphon eight siphon tubes to bring water from the lined canal to flood their onions So I worked with about 17 of these schemes with an average number of farmers of about 200 or so. I primarily worked with issues of “governance” surrounding these schemes (how is the water going to be managed and shared so that they all get an equal share?). But if you have never been to this part of the world then it is a treat. The fields are irrigated on a rotational basis determined by when water is released to them by the government agency that controls water deliveries from surface sources such as rivers. Baobob tree reaching estimated ages of 3,000 years old or more In southern Africa there is a tree that is quite remarkable called the Baobab or Baobob. I prefer to call it Baobob because it reminds me of me. Locals use it for as a food source by opeing the fruit (kind of dry on the inside) and sucking on the seeds. Kind of a citrusy flavor if you suck on the semi-dry pulp surrounding the seed. It is normally found in the drier regions of the country, regions such as IV and V. The outer bark can be removed multiple times from the trees without apparent damge to them and this is then woven into mats and used in the homes or the mats are sold along the roads to people passing by, usually tourists. Fruits of the baobob which has a pretty dry pulp on the inside but sucking on the seeds and the surrounding pulp of the seeds reveals kind of a pleasand citrusy taste The outer bark is removed from baobob, woven and used for making mats for flooring and sold along the roads

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The Problem With Pruning Pine Trees So They Don’t Blow Over

A fairly recent trend in pruning in Las Vegas has been pruning pine trees so they don’t blow over. We have some wind gusts that periodically get pretty nasty when they reach speeds of up around 70 mph (112 kph) or more. The trend was to remove some of the canopy so that there is not so much leverage on the root systems. This leverage, or sail effect, by the wind can pop the trees over when gusts come up quickly and our trees can be pretty shallow rooted which does not help to anchor them. This Mondale pine was pruned probably  in an attempt o reduce with wind load (sail effect)  on its canopyand help reduce the potential for blowing over You can see that removing the inner small branches concentrates the weight of the new growth all on the ends of the branches causing  them to bend and in some cases to break   I have some concerns about thinning pine trees to allow more wind to blow through their canopies. Not that it is done but really more about HOW it is done. Take a look at this picture of a pruned pine tree just for that purpose. Most pine trees will not regenerate new growth on older branches once this growth is removed. Once the wood is older than about three years old most pines will not cause new growth to come from this older wood. Once this young wood is totally removed, it is gone for good. By removing these small limbs in the interior it prevents pines like Mondale from renewing the removed growth. The juvenile part of the limb is now concentrated only in the growing tips which are all at the ends of the branches. This might be good in theory (the tree trimmers don’t have to come back as often). But this can create a problem.Think of a fishing pole. Why is the pole diameter tapered and not all the same diameter along its length? Poles or branches which are tapered help spread the stresses of bending along its length. If a pole or branch has no taper, then the stress of bending is concentrated in a very small area of the pole or branch which will increase its chances of snapping or breaking. By removing this small wood deep on the inside it also causes these “thinned” older limbs to no longer increase in girth (caliper or diameter).They bend more and more as the weight of the new growth is added to the ends of the branches. Pine tree with a canopy thinned a bit better so that limbs are less likely to bend and split A better approach would be to selectively leave some juvenile wood on the interior of these larger diameter branches so that these branches will increase in caliper and taper. So instead of removing ALL the small juvenile from branches deep in the inside, remove some but leave some as well. This still results in thinning and allows for wind to move throught the canopy easier and also results in distributing this increased load along the branches rather than concentrating the load in a small area of the branch which increases its likelihood of failure (snapping or bending). Just a thought.

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Sap Oozing from Plum Tree Trunk

Sap oozing from the trunk of plum Q. Last week I noticed sap bubbles 6 to 8 inches off the ground on the trunk of my year old Santa Rosa plum. I removed the bubbles and reapplied the whitewash. I checked again today and they are back. I’ve had plums before and the boars always win. I had hoped the Santa Rosa would do better. What can I do to save this tree? A. Bubbles on plum don’t necessarily mean borers. They can do this with high temperatures. If you don’t see any other evidence of borers like bark coming off especially on the south or west sides then I would leave it alone. Repainting is fine. Try to keep as much shade on the trunk as you can from the canopy or even lean a board on that side of the trunk to shade it if you care to. If there is chicken wire around it for rabbit protection you could wrap something around the chicken wire for some shad on the trunk. I don’t know of any difference between plums in borer resistance so I don’t think that would make any difference. But for now just get some shade on it.

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Roses in the Hot Desert Do Well But Different From Growing in New Jersey

Garden rose not doing well in our desert soils. They can do VERY well if you just follow some simple advice Q. This past spring I cleared a large “L” shaped area in my yard and planted 8 various rosebushes. They have sun from about 9 a.m. to about 5 p.m. They are watered in the evening and fed regularly. They are well planted with planting medium in large holes, and then mulched. All flowered during the spring and early summer. Now, however, they are very spindly looking. The leaves left on them are brown and the stems are turning brown. There are no bugs that I can see. I tugged on them and they are still firm in the ground. Have they died and should I replace them, or wait until spring and see what comes back? Should I cut them back, and if so, how much? I do not want to cut too much off. Leaf scorch on rose due to lack of soil improvement, no organic mulches used and not using an iron chelate as part of your fertilizer program A. Roses will grow best in an eastern exposure with protection from late afternoon sun. They can grow in full sun but they will be best grown in the exposure I mentioned. It is important to use a good compost mixed in the planting soil at the time of planting as well as a starter fertilizer high in phosphorus. Make sure your plants were planted the same depth as in the container or in the nursery if bare root. Make sure the bud union or dog leg on the stem is above ground and not buried. Make sure you stake the rose bush at the time of planting. The stake should not move if you do it correctly. I use a two foot piece of 3/8 inch rebar and tie the rose stem tightly to the rebar with green nursery tape and remove it after one growing season. Roses do well on drip irrigation. Use two emitters per plant or you can use drip pipe with inline emitters such as Netafim, Geoflow or equivalent product. If on drip it is important to note the amount of water the emitters deliver per hour and adjust your time on the emitters so that each plant gets about two to three gallons every time they are irrigated. Irrigations should be about two to possibly three times per week this time of year. Less often as it gets cooler but the length of time or hours should remain the same. Roses doing quite well in our hot desert climate and poor soils It is best to use a wood mulch rather than a rock mulch. All mulches must be pulled away from the rose stems at least 6 inches at the time of planting or the roses can get crown rot on the stem and die. Fertilize roses once in January with a rose fertilizer plus a soil applied iron chelate containing EDDHA. Follow label directions. You can fertilize again lightly after the heat of the summer has passed to help stimulate fall rose production. This should get you going. My guess is that they may have been planted too deep or the mulch touching the rose stems may have caused collar rot or irrigations may have been inadequate; either too often or not enough water. Just a hunch.

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