Q. I have two gardenias in the backyard in 15 gallon ceramic pots with good drainage. One of them is doing pretty well and the other not so well. Our backyard is on the north side so both are shaded most of the day. The picture I sent to you has leaves turning yellow and then brown on the interior of the plant although the ends of the branches still have green leaves. Both plants are on drip and watered the same. I added iron on top of the soil and also Vigoro 10-8-8 plant food but it doesn’t seem to be helping. The one I planted about 6 weeks ago has not done well. The other one was planted 3 months ago and is doing well with lots of flowers in May. Any suggestions for the one with the yellow leaves?  Gardenia leaves yellowing in potted gardenia. This could be salt accumulation. A. It is tough to acidify soils here in our desert due to the alkalinity of our native soils and our water. So if you can acidify the soil as best as you can, it will help. Ways to acidify the soil include using composts, raw composts, manure products, sulfur, acids and aluminum sulfate. My best shot at the gardenia is iron even though you added some. If you don’t use the right iron, it may not work. Use an iron chelate such as EDDHA with iron. You can pick up a one pound canister of this iron chelate locally at Plant World. I don’t know any other place it is being sold. Combine it with a soil application of your Vigoro fertilizer. You might also consider some of the Miracid products. Try to use fertilizers specially made for gardenias in the future if you can find one. If you can’t, use one for azaleas and rhododendrons. If you can’t find that, a third choice would be to use one for tomatoes, fruit trees or roses. Fertilize about once a month during the active growing season. These should be very light fertilizer applications. Whenever you are watering a plant in a container, you want to add enough water so that about 20% of the water runs out the bottom. This helps keep salts leached from the soil. Our tap water coming from the Colorado River is quite salty and you need to make sure the soil stays flushed of salts coming from the water. If you don’t, these salts will build up in the container soil and also cause exactly the problem you describe. You can’t let the soil go dry so it might be a good idea to buy one of those inexpensive soil moisture meters used for house plants which can give you a rough idea when the soil is dry and you should irrigate. You want the soil to dry down between waterings but not too much. If it doesn’t dry down, you may develop root disease problems on camellias. If you let them get too dry, they will drop leaves and the remaining leaves will become scorched. It is hard to judge when container soils are going dry. One way is to get an idea of its weight. You don’t have to lift it but just budging or moving it a little can give you an idea.

We need expert opinion soon about what to use as fertilizer for Greenway grass, bushes, and trees. Your advice please. Greenway grass Q. What is the range of N-P-K in cow manure that some landscapers use for grass? A. It’s really not fair to compare cow manure to a fertilizer because it really isn’t. They are using it more as a top dressing than as a fertilizer application. Manures vary in fertilizer content but are generally about 4% nitrogen and usually low in phosphorus and potassium. You should not rely on cow manure as a fertilizer. The fertilizer should be applied separately from a cow manure. An inexpensive fertilizer for starting plants and getting root growth from seeds, seedlings or newly planted trees and shrubs is 16-20-0 or DAP (18-46-0). Q. What inorganic fertilizer would you recommend and the amount/acre? A. For turfgrass you should never apply more than 1 pound of nitrogen every 1000 ft.² or 43 pounds of nitrogen per acre. In my opinion, this is excessive and should be closer to 1/2 pound of nitrogen per thousand square feet or 22 pounds of nitrogen per acre. This would be for inexpensive, quick release agricultural nitrogen fertilizers. If you are applying more expensive horticultural fertilizers that contains slow release nitrogen, then you can bump it up. How much to bump it up depends on what percentage of the nitrogen is slow release in the fertilizer.    Q. Use 10-10-10 at 500lbs/acre maybe? A. The fertilizer you mention has 10% nitrogen. It is not a good turfgrass fertilizer but it’s fine for trees and shrubs. In fact, turfgrass fertilizers are fine for trees and shrubs as well. The best turfgrass fertilizers are in the ratio of 3-1-2 or 4-1-2. An example would be 21-7-14, a 3-1-2 fertilizer. To apply 1 pound of nitrogen requires 10 pounds of fertilizer. Using your fertilizer you would apply 430 pounds of the fertilizer to get 43 pounds of applied nitrogen. Like I said, I think this is excessive and you will not see the difference once you exceed three quarters of a pound of nitrogen per thousand square feet or about 33 pounds of nitrogen per acre. In fact, if you apply 1 pound of nitrogen per thousand square feet it will push turfgrass growth quite rapidly. Q. How many times per year and which month(s)? A. For tall fescue turfgrass I would apply nitrogen four times a year; Labor Day, Memorial Day, Fourth of July and Thanksgiving. During the hot summer months I would always make sure you do not exceed 1/2 pound of nitrogen per thousand square feet or you could end up with some burning if people are not careful. If you are using mulching mowers you can skip the Fourth of July application. If you are using mulching mowers you should never exceed 1/2 pound of nitrogen per thousand square feet in a single application. Q. Should a roller of punchers be used immediately after fertilizing? A.I assume you mean aeration. Core aeration can be done any time of the year and does not really relate to a fertilizer application. The only exception might be when you are applying a high phosphorus fertilizer.                            Q. Should organic fertilizer (cow manure) even be used to fertilize grass? A. Cow manure is not a fertilizer. Bushes Q. What inorganic fertilizer (N-P-K) would you recommend and the amount/bush? A. Turfgrass fertilizers in the ratio I mention above are good for most trees and shrubs. You would apply this fertilizer in the very early spring or late winter. The amount to apply is similar to the amount you would apply to turfgrass but is calculated under the canopy area of trees and shrubs. A small tree that occupies 100 ft.² of canopy space would get 1/10 of a pound of nitrogen. A tree that had 1000 ft.² under its canopy would get 1 pound of nitrogen. The driver of growth for trees, shrubs and turfgrass is nitrogen. Q. Applied dry, or liquid, in the gravel around bushes? A. Dry fertilizers are applied near the irrigation source. If trees and shrubs are irrigated by sprinklers, then you distribute the fertilizer so that the sprinklers pushed the water into the rootzone. If these are drip irrigated, it is applied in the soil next to the drip emitters and the water carries a fertilizer into the rootzone. If you are applying a liquid fertilizer to the foliage obviously you have to wait for the foliage to appear in the spring to make an application. If this is a liquid fertilizer applied to the soil and make the application close to the drip emitters within a few inches under the mulch or under the turfgrass. Never apply a fertilizer to trees and shrubs deeper than about six or 8 inches. Fertilizer spikes are convenient but expensive. Liquid applications to the foliage last about 4 to 8 weeks. Dry fertilizers applied to the soil last longer if that’s important. Q. How many times per year and which month(s)? A. Most trees and shrubs will require a single application of a fertilizer to the soil during the months of December through about March. In a pinch you could go as late as April. Some plants tend to get yellow due to iron chlorosis or a lack of available iron. Usually a single application of an iron fertilizer that contains the chelate EDDHA is enough to keep them from yellowing. If these plants have been yellowing and are in poor condition for several years, this will probably not work in correcting a severe problem. The iron fertilizer should be applied at the same time as the other fertilizers, in early spring or late winter. Tall trees Q. What inorganic fertilizer (N-P-K) would you recommend and the amount/tree? A. You can use a good turfgrass fertilizer for most tall trees and shrubs. To be effective this fertilizer should be applied close to a source of water for the trees so that it is

Q. We are planning a wall to surround our yard so we can keep the rabbits out.  We live in Sun City Anthem in Henderson. We have been told that the local rabbits can jump very high, and our 3 foot wall will not work to keep them out. A. We have both the Desert cottontail and the jackrabbit. I don’t agree with the advice you were given. Our chicken coop wire at three feet tall was very effective at keeping them out of our vegetable plots as long as they could not lift the bottom edge of it with their noses or dig a little bit and get under it. Black-tailed Jackrabbit             Usually animals will not jump walls if they cannot see the other side. If they can jump to the top of it and look then that is different. I have never seen rabbits do that. But check and make sure there are not gaps in the wall itself. If they can get their head through a hole, they can get the rest of their body through it as well.

Q. My Australian bottle tree and African sumac are shedding leaves like a maple tree during fall.  However, they are also putting on new growth.  I specifically chose these trees because they remain green all year long. The bottle tree is about 20 ft. tall, on the north side of the house and gets about 20 gallons of water every day during the summer.  The sumac is on the west side and is about 12 ft. tall and gets about the same amount of water.  I’m about ready to cut them down due this leaf shedding. Were they stressed during the heat wave or what? A. These two trees have very different watering requirements. The bottle tree is a true desert adapted tree while the African sumac is not. Their watering needs are very different for this reason.             The bottle tree should never get daily watering. Even though the watering needs of the African sumac are more frequent, it should not get watered daily either. It is possible that these trees are dropping leaves excessively because their roots cannot “breathe” due to excessive moisture in the soil. Bottle tree in desert landscape             At the most, the sumac should get watered deeply twice a week right about now. The bottle tree less often than that but when it does get water it should be deeply as well.             Evergreen trees do drop their leaves. No plant is without leaf drop. Some keep their leaves longer than others.             Normal leaf drop time for evergreen plants is during or shortly after new growth. As they put new growth and new leaves on new branches they drop older leaves from older wood. This is normal. However, excessive leaf drop is not. This can indicate stress ranging from drought to overwatering.             Please get on a deep and infrequent watering schedule rather than a daily one. This time of year the only things watered daily are fescue lawns, annual flower beds and vegetables. The larger the plant, generally speaking, the deeper the root system, the less frequent the watering but the amount of water applied each time is higher.             Frequent, shallow irrigations force roots to grow shallower and decrease their tolerance to droughty conditions. Both of these trees can develop root rot from frequent watering and death. Excessive leaf drop can be a sign that this is happening. Bottle tree in lawn             I would begin to back off to watering every other day for right now but increase the amount you give them each time you water. Both can handle the heat but not daily watering, particularly the bottle tree.             Make sure the applied water is distributed evenly under the canopy either by having several drip emitters under them or watering them in a basin and flooding the basin. The water should not be applied in one location under the canopy. Back off on the daily watering. I hope they are not in stages where you can keep them from getting worse.

Q. I have a golden barrel cactus that has grown to 3ft wide in a place that I cannot leave where it is. It’s a beautiful specimen, but I have to remove it. Any ideas on how to move it?  The thorns are lethal. A. Now is actually a good time to move cacti. They can be moved any time except during, and about two months before, winter weather sets in. Unlike many other types of plants they do well moved in the summer.             When we have moved these sized cacti in the past they were easy to move, taking the relocation without a hitch. We used a lot of thick gloves and old carpet remnants. We dug a trench around the cactus with a pick about 12 to 18 inches from the plant to a depth of about one foot.             We then watered the trench to loosen the soil a bit and make digging easier in that lousy soil. We then began under cutting the plant to loosen the soil and cut the roots. We stopped when the roots had mostly all been cut and the plant seemed easy to roll with leverage from a shovel.             Laying the carpet remnant to the side of the plant we were able to free the cacti and roll it on to the carpet pad. We then placed the cactus in a shady spot to heal the cut roots for two to three days before we planted it again.             Our hole was dug and amended with compost, phosphorus and large rocks removed. The hole was cleared so that it was larger than the root ball of the cactus.             After that healing period we moved the cactus to its new location and gently rolled it into its new location.  We then placed the amended soil around the roots and watered it in to remove air pockets.             We tried to get the cactus at the same depth as it was in its old location. After the soil had drained of water we came back and added more amended soil until it was at the same depth and watered it in again.             Once planted at the right depth we then watered deeply around the cactus no more than once every two to three weeks in the summer heat. In the fall it dropped to once a month and the winter only once during the winter cold.             The next spring we watered once a month and increased it to every two to three weeks during the summer heat until we saw signs of growth. We then had to make a decision whether we wanted to make it grow more or not.             If we wanted it to grow, we kept it on the same watering routine and added nitrogen every few months. If not, we reduced the watering to twice or three times during the summer and once during the winter with no additional fertilizer. I hope this helps.

Lawns are getting toasted right now. This is a truly stressful time of year for plants, particularly plants that are not truly desert plants. Temperatures are out of their “comfort zone” and they become highly susceptible to diseases because they are less capable of fighting through a problem. I warned on June 10 of 2012 and July 1 of this year on my blog that lawn diseases were“right around the corner.” If lawns are going to have problems, they will happen now. Sign up for my free newsletter through my blog and you will receive notices when things like this are happening in our community. Your email address is never shared.  

Q. I have a healthy sago that is outgrowing its space rapidly. When is the best time to relocate it? Is relocation successful usually? It is such a nice plant that I hate to risk endangering its life.   A. You would move it this fall, some time between the end of September and mid-October, or next spring. You should not have a problem relocating it. I would not put it any closer than five feet from anything you don’t want it to touch or invade like a sidewalk or wall.             Hopefully you will put it on the north or east side of a building or in a spot with a little wind and sun protection and not use rock mulch around it. Pre-dig your hole for the plant. Make sure the hole and soil for replanting are prepared well with compost and a starter fertilizer high in phosphorus.             Remove the bottom tier of fronds from the trunk. I would leave only the fronds which are at about 45 degrees from horizontal and the inner fronds. Remove the older ones that are below this point. Bend the remaining fronds up around the central bud and wrap some twine around them to hold them together if they are pokey.             Take as much of the root system you can when you move it. Cut deeply with your shovel all the way around the plant about a foot to 18 inches from the trunk. Cut the roots in a complete circle all the way around the plant at least twice making sure all the roots are cut. Cut as many of the roots as deeply as you can.             On the third trip around the plant cut in the same spots but push down on your shovel handle and begin leveraging the palm upwards. Move to a new spot and repeat it until you have gone around the plant, leveraging and lifting, the third and fourth time with your shovel.             The plant should almost be free now or, if you are in luck, it can be lifted by the fronds. If not, then push the plant on its side and cut any remaining roots with your hand shears to free it. Tying the fronds up should make it easier to do all this and move it.             Move and orient it so it looks nice. Don’t worry about orienting it the same compass direction as it was before. Backfill around the plant and run water in the hole at the same time you are backfilling to remove any air pockets.             Plant it the same depth as it was in its original hole, no higher or deeper. Put a small moat around the plant to contain water from the hose when hand watering. You can drip irrigate the plant but still hand water it for the next 2 to 3 weeks, filling the moat each time. Untie it and release the fronds.             In the spring, remove the bottom layer of fronds at the base of the crown just leaving juvenile fronds that are upright. You will see new growth from the center and it should regrow and fill the canopy in the first year.

Q. I believe I am dealing with some fungal outbreak on my new lawn. About a month ago I started to see faint circles of stressed lawn. They range from 24 to easily 48 inches wide. They are certainly not dog urine spots. I know the difference.  Also confident it’s not a watering problem. All spring and early summer the lawn has been healthy and looking great. But now these circles are appearing everywhere.  Am I going to need to just throw in the towel and start over? A. This is most likely a fungal disease called Summer Patch. Buy a lawn fungicide at your local nursery that either says it controls Summer Patch or (less likely) as well as necrotic ring spot disease.             Fungicides are primarily preventive so making an application now during this hot weather will arrest the disease from going any further but not reverse the damage done. Look for a turfgrass fungicide that states it will control Summer Patch disease, Fusarium diseases or “frog eye” on the label. Follow the label precisely in application. If the label states it also controls Necrotic Ring Spot as well, so much the better.             This is a “hot weather” disease of lawns and favors soils that stay wet and don’t drain readily. Since this is a hot weather disease, you can always expect it to occur when temperatures are rising and become particularly aggressive during the “summer monsoon” season where relative humidity takes a bump along with high temperatures.             Next year anticipate an outbreak to start in June and make your preventive fungicide application then or when you start to see those “faint circles” appearing.             I would aerate the soil now as well. You can use a simple hand aerator that you can buy at the nursery or you can rent a power aerator from a local rental company. Don’t use the shoes with the spikes on the bottom. They are a gimmick.             Remember this problem area in the future. Prior to the onset of hot weather, aerate to improve water drainage from the area around grass roots. Mow the lawn at its minimum acceptable height (usually 1 1/2 inch for tall fescue) to improve air circulation in the stand of grass.             Avoid excessive applications of nitrogen fertilizers but keep the lawn fertilized “adequately”. This will usually mean about half the label rate mentioned for lawns on the fertilizer bag.             This is particularly true if you are mulching the clippings back into the lawn with a mulching mower. Returning the clippings to the lawn with the mulching mower has no bearing on this disease in a lawn.

Q. I have ‘Vee’ shaped cross marks on my tomatoes (especially from Celebrity tomato) starting from the stem and reaching out and down about 1/4 the side.  I always thought these were from lack of water but we try to give all extra water by letting the hose end flood each for 5-10 minutes at least once a day in addition to drip irrigation at 1am, 3am and 5am for 6 minutes each. A. I think you either are explaining either “catfacing” or “cracking” of the fruit. This is a surprise since Celebrity is known for its lack of both and was developed with one of its intentions to reduce cracking. Some of this type of prevention is by picking the right variety (Celebrity should be one!) for growing and some is garden management. Fruit cracking on Caspian Pink heirloom tomato             Two things I can think of contribute to cracking. Catfacing is a different issue. I gave you a couple of links to look at to determine what  you might have. Cracking can be down the side from the stem or around the circumference of the fruit.             Two things important in cracking are how well the tomato skin will expand without breaking (cracking) and soil moisture. Try to water in the early moring hours several hours before it gets hot.             Secondly, cover the soil with a light mulch like straw to help slow down the loss of water from the soil. Radial cracks on Caspian Pink             The last thing is something that I think most people neglect. Good soil preparation at the time of planting. If the soil is pretty heavy and not “fluffy” or what we call “crumby” (like bread crumbs kind of crumby or a cake-like texture) the roots of the plant will be forced to grow close to the soil surface.             If the majority of the roots are close to the surface where water is lost quickly during the heat the plant will go into water stress (drought) very soon after an irrigation. If the soil is prepared well so that it has a “crumby” structure then plant roots are distributed through the soil so that it can take up more water before it becomes water stressed.             Going from water stress to water abundance leads to expansion of the fruit and can lead to splitting. Having enough foliage covering the fruit can also reduce cracking so good canopy coverage of the fruit is important. Topdressing with straw mulch             So make sure you soil is well prepared to a depth of at least 12 inches when planting or plant in a raised bed with well prepared soil. Secondly, apply a surface mulch no later than when the fruit begins to set.             Third, water at the beginning of the day before it gets hot to reduce water stress. Fourth, make sure the plants are healthy and have good foliage covering the fruit. This means the right fertilizer at the time of planting and followup monthly fertilizer applications when you see fruit setting and you are harvesting. These are small applications of fertilizer or lightly foliar feed in the early morning hours.

Q. Will either dwarf lime or lemon trees do well here? We consider pots but our patio faces the west and gets very hot. We have a small space for pots in the front yard which faces east. Any suggestions?   A. The principle limitation for citrus here is winter cold. Cold tolerance in citrus generally follows this progression of tolerance from the most hardy to least goes something like this: (most) kumquat, Meyer’s lemon, grapefruit, Mandarin or Satsuma orange, navel orange and lime (least). Eureka lemon tree in Las Vegas. Fruit still immature.             Once you get to navel orange the rest will not handle any freezing. You should locate citrus in the part of the yard that is the warmest in the winter and protected from cold winter winds.             If you like lemons, Meyer’s is a good choice and very popular in Las Vegas even though it is not a true lemon. I would put limes only in much protected locations.