Update on Grape Leaf Skeletonizer from Reader

I big thanks to Powell Gammill from Phoenix, Arizona, for sending these pictures along with his comments on grape leaf skeletonizers.

Attached are two pics I took last year that capture a female laying eggs (note precise characteristic pattern)

Grape leaf skeletonizer laying eggs on the grape leaf surface.
Picture courtesy Powell Gammill.

and a pic of newly hatched 1st instar larvae (and one 2nd stage) in uncharacteristic (non-line) feeding pattern (which I hope may indicate a viral infection is established around my vines) and a couple of organized egg clusters.  You can reprint them if you wish.

Grape leaf skeletonizer eggs laid (right bottom) with larvae hatching from eggs at center, bottom.
Photo courtesy Powell Gammill.

In addition to the Btk and spinosad, you can use dormant oil before leafing and horticultural oil to try and kill the molting larvae under the vines (but this would kill any emerging parasitic wasps as well).  By rotating treatments you can hopefully prevent resistance.  I have found a easy method of reduction is to look under the leaves and remove any infested leaves before they hatch or get large enough to move on.  They strip a leaf at a time and are not too hard to spot if they are still young and on a leaf.  Also the adults can't fly very well and look inelegant in flight.

Grape leaf skeletonizer adults.
Photo courtesy Powell Gammill.

As you said, if you pick the 3rd and 4th instars off manually do so with gloves and remove them as if you just drop them unharmed they may either find their way back to a vine or go to ground and cocoon. 

I think these were drying out getting ready to start flying.  Note, ours (Phoenix, AZ) have an orange head.  They too are reportedly irritating (cyanide?) to the skin...I know the larvae have irritating bristles.

Beautiful Moth Now, Deadly Assignment in Your Garden

I was working in the garage the other night, cleaning out some things and holding a small box. The overhead light was on so I could see the small box in front of me. Startling me, this flew in and landed on the box, attracted to the light.

Of course this is not my picture but can be found at

http://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/images/hawkmoths/eumorpha_typhon_lg.jpg This is the sphinx moth, hawk moth or sometimes we call them the hummingbird moth because they can pause in mid-air in front of a flower and sip up its nectar. However, my moth was gone as soon as I tried to get my camera. But the feds site will let me use their picture.

You will see them flying now, usually around dusk although they feed on the nectar of flowers and serve as very good pollinators, particularly of flowers with very long "throats". This is because their "tongue" is so long. But....there is a problem for gardeners.

This is the hornworm and it is the larva or immature (baby) of the sphinx/hawk/hummingbird moth. You will see them devouring grape leaves (one of their favorites), tomato leaves and other garden crops. They can be devastating this time of year and you might see them again in the fall.

 

It is your call but if  you want to control these "caterpillars" or larvae then use Bt (Dipel or Thuricide) or Spinosad for organic control. It will not harm the adult moth but will help in controlling the eating by the larvae. This will of course prevent the larvae that you kill from becoming more moths.

Watch for Grape Leaves Disappearing - Skeletonizer Flying

Q. I just sited my first grape leaf skeletonizer moth. I’ve learned that Bt will control the worms.   I’d like to try and minimize the larvae if I can by eradicating as many moths as possible. Can you recommend the best course of action, if any, to control the moth itself?

Grape leaf skeletonizer adult moth

A. Not a lot of people know what they look like. They are a dark, blue-black moth that resembles a wasp more than a moth. I will post a picture of the moth, eggs and damage on my blog for all to see. If you have grapes, everyone should start looking for these guys.

Grape leaf skeletonizer larva feeding ont he underside of grape leaf. This picture courtesy University of Arizona
and can be found at http://cals.arizona.edu/yavapai/diagnostics/Assets/Images/Insects/grapeleafskeletonizer1.jpg

            The adult only lives for about three days. Pretty much its sole purpose is to reproduce. The damage comes from the larvae eating the leaves, not the moth eating the leaves. The eggs are laid on the bottom of the leaf. The life cycle of the insect is about 60 days (two months). It takes about 7 days for the larvae to hatch from the deposited eggs.

            I know you want to control the adult in an attempt to control the young but it probably is not the best approach since the adult will be hard to kill. Soap and water or insecticidal soap will work IF the soapy water comes in direct contact with the moth. But since the adult does not eat the leaves, you would have to actually spray the adults to kill them.

            The larvae are fairly easy to kill since they eat grape leaves. You must spray it on the bottom of the leaves. Do this by pointing your applicator so it sprays up, on the bottom of the leaves. The Bt (Dipel, Thuricide) has about a one week residue on the leaves.

            Spinosad will also work and has about the same staying power but is a little harder on bees.

 

A word of caution: These larva are nasty critters. If a larva falls on your skin it will feel like you were burned by a matchhead.

Pruning Fruit Trees at Planting

Q. I planted some barefoot fruit trees earlier this year and unfortunately several did not survive. This was my fault since I didn't get them planted right away and the roots may have dried out.  I want to replace them with container nursery stock. The problem is that I want to prune the trees to knee to height per your ladderless orchard recommendations. All the nursery stock trees have limbs well above this height.  If purchased and planted now, can these trees be cut back to the lower height when planted and survive?

 

A. They can be pruned back provided the stems are not too large in diameter. Pick smaller container plants that are in good health. They will catch up or even surpass the size of larger container stock.

            I would make sure that the stem or trunk is well under an inch in diameter so you can cut them back. This should produce several new stems about 8 to ten inches below your cut.

            Some fruit trees sucker better than others. Peach and nectarine, for instance, have a harder time sending new shoots up after they have been cut if the diameter is too large. You should not kill the tree if you do this provided the diameter is small.

Insect Damage to Kiwi But Can't Find Insect

Q. I have a bit of a quandary. My male kiwi died and I did everything I could do to keep it alive. I then contacted Parks Seed and they sent me a new male free of charge, not even shipping. But then something started eating the leaves of my female kiwi. I searched every leaf and found nothing. I thought whatever it is must be eating at night and hiding during the day. I was right. It was a beetle. I found and identified the culprit; a black vine weevil. Now here is my question. If they have laid eggs in the pots (still in their one gallon originals) of my new male or the original female what do I do to stop the infestation if there are eggs or already larva feeding on the roots?

 

A. Kiwi is a bit cold sensitive for some parts of the valley. So be careful during the winter. However, we should be able to grow hardy kiwi here in most locations. You will have a hard time managing this plant in a 1 gallon container for any length of time. I would get it in the ground.

            Yes, it could be a black vine weevil or possibly root weevils which are more common here. It is possible the plant came to you with black vine weevil as a hitchhiker. Black vine weevil adults emerge in spring and cause plant injury by feeding upon blossoms, clusters, and small fruits.

            I would follow the same recommendations for growing it as our fruit trees; plant it in the ground with lots of compost at the time of planting, water it in thoroughly and stake the plant to keep it from moving, mulch the surface of the soil with organic mulch.

            If you collect some from the leaves at night and send it to the state entomologist through the State Department of Agriculture we can get this resolved.

            Control efforts are usually directed against the larvae living in the soil. Root weevils come out at night, as you have discovered, and chew on the edge of leaves leaving the edges of the leaves very raggedy looking. Control is difficult but they usually do not cause extensive damage that would kill the plant.

            When they feed on ornamentals we usually just ignore root weevils. If it is black vine weevil you would be looking at applying an insecticide to the soil in the container in an effort to control the larva or immature forms. You would need to look for an insecticide which lists that it controls vine weevil, can be used as a soil drench and is labeled for fruit crops.

Roses Growing Weaker After Installing Rock Mulch

Q. I have some well-established rose bushes (15 years) in our front yard. Five years ago we converted to desert landscape and the landscaper put about 3 inches of small rock in the area containing the roses. They seem to be healthy although the density and beauty of the blooms was weaker last year.

            I've been using liquid Miracle Gro. Is there a better liquid fertilizer, or should I consider pulling the rock away from the bases and fertilize through the soil. Thanks.

 

Not the readers rose but what can happen to roses over time growing in rock
mulch and little care.

A. Miracle Gro products are fine but I would also add a separate iron fertilizer. Go to your local nursery and get a one pound canister of iron EDDHA. Follow the label directions but I find it more effective to mix in a teaspoon of the product in a gallon of water and water it into the rootzone of each plant.

Some of the Miracle Gro specialty fertilizers. Actually any of these would interchangeable. Miracle Gro might disagree
but these labels are mostly to help novice gardeners select a fertilizer for specific plants.

            Each rose should get maybe one teaspoon January – March, a once a year feeding. Although best applied early, an application will work now. They should be all right if you keep it on this fertilizer schedule. Select a product that has a big middle number. There are several different ones to pick from and I don’t know their product line off the top of my head.

This is the correct iron chelate to use in our high pH soils.

            Feed roses about every two months lightly starting January – October. However the iron is needed just once a year. Do not neglect soil improvement as well by using composts and organic mulches that decompose into the soil. Roses will really appreciate wood mulch much more than rock mulch.

African Sumac Limbs Splitting

Q. Could you please give me some clue as to why my 10 year old African Sumac tree has started to get split limbs. They are splitting laterally along the length of the branch. I have had to cut off two branches in the last week because of this splitting.

A. This is the first I have heard of this problem with African sumac. Who is making the decision to remove the limbs and what is the reasoning behind it? I would be curious because there are unscrupulous maintenance people who will point out something to a homeowner and recommend a job to make money. Also, there are uneducated maintenance people who will point out something to a homeowner and recommend a job to make money.

            Sometimes natural furrowing of the bark can be mistaken for cracking. I have had several homeowners get concerned and send pictures and that is all it is. I have had African sumacs split due to snow loads on the branches but that is reasonable.

            Most reasons for cracking would be excessive weight on the limbs. Are you sure there are no children doing pull-ups on some limbs?

            This is a stretch but if the tree were growing very rapidly and pruned incorrectly I could possibly see that limb cracking might occur. Without a bit more information that is about all I can tell you with the information you gave me.

Has anyone else seen this? I would love to get some pictures so I can see the problem.

Pine tree limb splitting due to lack of taper along the limb. The weight of the branch on the end was too much for it
after a light snow. The tree was thinned to allow for less resistance to wind to lessen blow over. Improper pruning caused
the limb to not develop good taper resulting in splitting.

Moruga Scorpion chili and Bhut Jalokia Pepper Plants Available Until 5/12/13

Hi, I just subscribed to your blog, looks nice. I have 7 Moruga Scorpion baby chili plants, and 1 Bhut Jalokia that need a good home. I am out of garden room. They are free to a good home. Contact if you are interested.

Sincerely, Craig

 

Send me an email, Extremehort@aol.com and I will get hold of Craig for anyone who is interested.

 

Worlds Hottest Pepper http://en.wikipedia.org/wiki/Trinidad_Moruga_Scorpion

 

Previous hottest pepper

http://en.wikipedia.org/wiki/Naga_Bhut_Jolokia

 

 

Tomatoes Not Setting Fruit? Shake It Up Baby!

Q. I have only gotten into gardening in the Vegas area the last 3 years and have been successfully growing tomatoes the first 2 years. But I noticed last year that I didn't get nearly the same number of tomatoes that I harvested in previous years. I have a raised bed that I started with a blend of about 4:1 of cheap compost and our desert soil.  The soil level is at least 2 1/2 feet deep.  Each year I have continued adding compost from my own yard and vegetable scraps, at least 3-4 inches of compost each year. I have periodically used a Star Nursery fertilizer as well (the one designated "for vegetables/fruits"). 

 

The watering for the tomatoes is set to a timer such that during the full heat of summer the plants get watered twice a day (about 10 minutes each time), less frequently when the temperatures are lower. There is microtubing with an adjustable drip emitter used to water the plants. The watering scheme has been unchanged the past 3 years. The plants get full sun all day.

So last year the tomato plants themselves grew well and I saw lots of flowers, but the tomatoes just never developed. This was even before the heat of summer hit. I think I harvested about a third of what I did the year before.

 

I noticed a lot less honey bees this past year in general as well. I have grown other mixed vegetables that have all done well so I am assuming the nutrient content in the soil is ok. Is there anything I could be doing differently to help get more tomatoes?  What about Mason bees? Are there flowers I can plant to attract bees for better pollination?

 

A.  Let's look at the list of things that could affect fruit production. These would include the right temperature range, wind, good soil preparation, disease, pollinators such as bees, humidity, sunlight and a few other things as well. If we have a long, cool spring we can expect to potentially have good production of fruit. If the spring is erratic and goes from cold to hot in a short period of time we can expect poor fruit production. I will tell you a little trick you can use in a bit but I want to make sure you read the rest of what I have to say. Little tricks do not work all by themselves. You have to do the whole package to be truly successful.

 

Irregular Production

 

Let me first comment on the irregular tomato production. Our desert climate is not the best climate for tomato production. We have a very short spring sometimes. The spring months as well as the corresponding fall weather, are the best times for tomato production here. When it gets too hot, tomatoes stop producing. Tomatoes are very sensitive to both hot and cold weather and have a more narrow acceptable temperature range than peppers or eggplant which are in the same family.

 

Tomatoes do not set well above 90°F and don't set it all when it stops 95°F. If bees are not working during the cooler parts of the day, you will get poor fruit set. Pollinators are very important and if they are not working when you need them or they have a very narrow window of opportunity then production will be down. Fruit set in the cool spring usually means you will get tomatoes in June and July and then they stop producing Et al. in August because it was too hot for fruit set.

Soil Improvement

Desert soils that are raw (never in production before) are ripped deep with an irrigation
trencher prior to preparation to open the soil for organic matter additions.

You have to be very careful about compost and if you use cheap compost your garden could be in trouble. When I prepare our desert soil for production I use an equal mix of good compost and native soil to begin with and I construct raised beds with outside walls. I will use compost that I know is good quality or make my own. I emphasize this... there is no good quality compost available for sale in Las Vegas. They are making some compost at the Las Vegas Springs preserve which is pretty good stuff but they are not allowed to sell it. 

 

The second year of production I add about half of the amount I used the first year. The third-year I add about the same amount as the second year. By the third year, that desert soil will become extremely productive. At that point, I only add compost to the area that I'm planting, not the entire growing area.

 I typically modify the soil to a depth of about 12 to 18 inches. However, I do rip the soil as deep as I can with an irrigation trencher when I first began constructing the raised beds.

 I strongly suggest not to use any compost without knowing what's in it. I am going to put a caveat here... the last time I looked one bagged compost that didn't seem too bad was Kellogg's. However, I believe they were using biosolids from Southern California. I believe the bag said not to use it for vegetables. I think this was available either from Lowe's or Home Depot but I have not looked for quite a while.

Good Varieties

Yellow pear tomato

You don't mention which varieties of tomatoes you are using and that can have a huge impact on production. Usually, varieties like Early Girl, Celebrity, Jet Star, Big Boy, Better Boy, and a grape tomatoes, yellow pear and cherry tomatoes will set when others do not. A couple of those plants are good indicators that least you are getting pollination.

Check your varieties and make sure they get in early. Try to keep them out of windy locations and you mention full sunlight but make sure they have a minimum of six hours.

Pollination and Pollinators

 It is not just getting flowers that are heat tolerant, you need flowers that are blooming at the right time as your tomatoes. Having bees coming to your yard during the heat will not help tomato production. They need to be blooming at the same time and this usually means spring flowering perennials and fruit trees.

I was only taking a guess about mason bees. Rather than encourage that type of be which might struggle in our climate I would encourage you to look at our native leafcutter bees which pollinate alfalfa and other legumes. You might also consider clovers and other legumes as a mix for attracting bees.

 

Finally the Hint

There are two ways of getting tomatoes to set fruit without pollinators. One is the use of applied hormones you can spray on the flowers to set fruit (parthenocarpically) without bees. These are sprays you can buy in the nursery.

The second method is a technique that green house growers use when they grow tomatoes because they dont have pollinators in their houses either. An electric toothbrush. It appears that the physical visit of a bee to the flower is not the only thing that trips the setting of fruit but the vibration caused by the wings of the bees. So when temperatures are good and you see flowers, walk over to your tomatoes and gently flick the flower clusters with your finger or use an electric toothbrush and vibrate the flower clusters for a few seconds to improve flower set.

 

Effect of High and Low Temperatures on Tomatoes and Peppers

The Effect of Extreme Temperatures on the Tomato and Pepper Crop

Author: Janice LeBoeuf - Vegetable Crop Specialist/OMAF Creation Date: 16 June 2004 Last Reviewed: 2 December 2004   Freezing and chilling injury in tomato and pepper plants Although frost occurs, by definition, when the temperature drops to 0º C at 1.5 meters above the ground, this may or may not result in freeze damage to crops. The actual temperature at which freezing will occur depends on such factors as plant species and variety, plant vigor, soil conditions, surface cover, duration of the freezing temperature, thawing conditions, cloud cover, and wind conditions.   In tomato, freezing causes a darkening of the leaf or stem tissues. Damaged areas later wilt and turn brown. It may be difficult, initially, to determine whether the growing point has been killed and damage may become more evident on the day after the frost. Peppers are more sensitive than tomatoes to freezing temperatures and may be injured or killed by a light frost.   Tomato plants are also susceptible to chilling injury at temperatures between 0 and 5º C. Chilling can cause stunted growth, wilting, surface pitting or necrosis of foliage, and increased susceptibility to disease. Low soil temperatures also stunt plant growth and prevent root development. Temperatures below 10ºC during flowering can interfere with pollination and result in catfacing of fruit.   Pepper plants experience chilling injury with prolonged temps of 0-10º C (32-50ºF). Injury may show up as puckering of the leaves and stunting of the plant.   The effect of temperature on flowering in tomatoes and peppers It is well known that flowering, pollination, and fruit set of tomatoes and peppers can be adversely affected by temperature extremes. The effect of various temperatures during flowering and fruit set of peppers and tomatoes is shown in Tables 1 and 2.   Table 1: The effect of temperature during flowering and fruit set of tomato Temperature Effect on flowering, pollination, fruit set Greater than 35° C (95° F) Reduced fruit set 18.5 – 26.5° C (65-80° F) Optimum for fruit set Less than 13° C (55° F) Misshapen or catfaced fruit may result Less than 10° C (50° F) Poor fruit set     Table 2: The effect of temperature during flowering and fruit set of pepper Temperature Effect on flowering, pollination, fruit set Greater than 32° C (90° F) day temp. Pollen sterility occurs, flowers may drop 16° C (61 ° F) Optimum for flowering and fruit set Less than 15.5° C (60° F) or greater than 24° C (75° F) night temp. Poor fruit set   What you may not think about when you see blossoms and fruit developing, is that low temperatures experienced by the plant weeks before flower buds were visible, can also affect flowering and fruit set.   A tomato plant which experiences temperatures below 15.5ºC (60ºF) for extended periods of time will begin to flower profusely. These flowers may remain open on the plant for several weeks, without fruit being formed. Larger flowers and increased branching of clusters can show up as a result of low temperatures experienced by the plant weeks before flower buds are visible. Believe it or not… Daytime temperatures of 15.5°C (60°F) with night-time temperatures of 10°C (50°F), four to five weeks before a tomato flower cluster blooms, may result in misshapen or catfaced fruit. Fact… Night temperatures of 7-10°C (45-50°F) during pepper flower development can cause the fruit to be smaller than normal, or somewhat misshapen. Chilling and freezing injury of tomato and pepper fruit The fruit of warm season crops like tomato and pepper can be injured by low temperatures. Chilling injury occurs in tomato fruit if they experience temperatures of 10ºC for longer than 14 days or temperatures of 5ºC for more than 6 to 8 days. Tomato fruit exposed to a shorter duration of low temperatures may still be prone to storage problems, even if obvious injury did not occur in the field. Pepper fruit can be injured by prolonged temperatures below 8ºC.   Frost injury is more severe than chilling injury. Tomato and pepper fruit are usually damaged between 0 and –1ºC. http://www.omafra.gov.on.ca/english/crops/facts/info_tomtemp.htm

Japanese Privet Invasive in Landscapes?

Q. I have a narrow area and the local Vegas nurseries have Japanese privet However, I have read on various blogs that birds eat the berries and they get dropped in other areas of the yard and gardens, sprouting up all over. They say it is considered an invasive species in many areas. Have you found this problem to be true and if so, is there anything that can be done so that the plant will not produce berries?

A. I have not heard this to be true in desert landscapes. We can control most growth by controlling water. Where water is applied to desert landscapes, these are the places where weeds and other unwanted plants will grow. There are many invasive species in California and Florida that are not invasive in home landscapes in our desert for this reason.

Leaves of Japanese privet under stress. Notice the curling, lack of density of the foliage and off color appearance.

            However, invasive species can be a problem in persistent or perennial waterways such as the Colorado River basin, washes like the Las Vegas Wash and irrigation ditches. So you do have to be careful with invasive species but in the middle of the desert with no such waterways it is not usually a problem.

            During the establishment period you would want to push stem growth as quickly as possible with deep irrigations and light fertilizer applications about four times a year. Pruning should be done about monthly during establishment and to keep the trellis looking neat and trim.

Kumquat Yellowing in Landscape Planting

Q. Here is one of two kumquat trees that I am trying to grow. As you can see it is not working.  I feed and water them what is the problem? Can you help?  Or should I discard?

 

A. The issues on the other picture could be related to a mineral fertilizer problem. This one could be the same but with the leaves gone it is hard to tell.

It also might be related to whatever soil amendments you put in the ground when you planted the trees. But I am pretty confident it has to do with the soil, fertilizer issue or irrigation.

It does not help much that they are surrounded by rock mulch. Let’s handle one at a time. Make sure the tree was planted in your soil at the same depth it was in the container. If there was some extreme cold weather, it might also be cold weather damage if you did not see this before it got real cold.

Irrigation. Irrigations should be generous but not frequent. A tree that small can get by with ten gallons of water at each application. If these are on drip emitters you should have enough emitters or run the minutes long enough to deliver ten gallons at this size in its life. This time of the year once a week is often enough. When you start to see new growth, bump it up to twice a week with the same volume of water each time.

Fertilizer. Go down to Plant World Nursery on Charleston (they are the only nursery I know of in town that carries this) and buy a one pound container of iron chelate fertilizer. If you ask for Doug, Brian or any of the main staff they will direct you to the right one since I recommend it a lot. They even have my name on the label now so people will believe them when they direct them to this product.

 

For each tree mix about two or three tbs in a one gallon container, stir it and distribute it around the base of the tree where the drip emitters are. Water it in with another gallon since it is sensitive to light. Get some rose fertilizer (like Miracle Gro type) and use it on the kumquat or get some fruit tree fertilizer stakes and put the fertilizer under the rocks or drive two stakes close to the emitters. I think the Miracle Gro is better. Fertilizers are salts. Keep all fertilizers at least 12 inches from the trunk when applied.

Mulch. If this were me, I would pull the rock mulch back a couple of feet and put down some good compost (don’t buy cheap stuff) and lightly dig it around the trees from the trunk to a distance of about two feet from the trunk. I would cover the area around the tree in wood mulch but not bark. Keep wood mulch six inches away from the trunk so that it does not cause the trunk to rot if it gets wet. Older trees it doesn’t matter.

Lets see if this works for you.

Suggested Landscape Practices for HOAs and Their Landscape Contractors

Q. We need expert opinion soon about what  to use as fertilizer for Greenway grass, bushes, and trees. Your advice please.

Greenway grass:

A. What is the range of N-P-K in cow manure that some landscapers use for grass?

Not sure what you mean by a "greenway" grasss.... but....It's really not fair to compare cow manure to a fertilizer because it 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).

 

B. What inorganic fertilizer would you recommend and the amount/acre?

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 horticulture fertilizers that contains slow release nitrogen, then you can bump the application rate up and apply it less often. How much to bump it up depends on what percentage of the nitrogen is slow release in the fertilizer.  

 

The fertilizer you mention (10-10-10) 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, is a 3-1-2 ratio fertilizer. To apply 1 pound of nitrogen with your 10-10-10 fertilizer requires 10 pounds of fertilizer. Using your 10-10-10 fertilizer you would apply 435 pounds of the fertilizer to get 43.5 pounds of applied nitrogen (there is 43,560 square feet in an acre or 43.5 thousands of square feet). Like I said, I think one pound of nitrogen per thousand square feet 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 and cause alot of mowing during cool weather. Do you really want that?

 

Negotiate. If you use only half the fertilizer (1/2 pound per thousand instead of one pound per thousand) then use a better fertilizer at half the rate. Cost of the fertilizer is the same or better.

C. How many times per year and which month(s)?

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.

 

D. Should a roller of punchers be used immediately after fertilizing?

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

 

E. Should organic fertilizer (cow manure) even be used to fertilize grass?

Cow manure is not a fertilizer. Fertilizers will have the amount of N-P-K listed on the bad as required by state law.

Bushes:

A. What inorganic fertilizer (N-P-K) would you recommend and the amount/bush?

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.

B. Applied dry, or liquid, in the gravel around bushes?

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.

C. How many times per year and which month(s)?

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:

A. What inorganic fertilizer (N-P-K) would you recommend and the amount/tree?

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 washed into the rootzone. It should not be applied deeper than 6 to 8 inches in the soil. Other fertilizers in ratios like 1-1-1 are also okay but the high phosphorus of the middle number is really not needed unless these are flowering trees.

B. Applied dry, or liquid, near the end of branches around trees?

Fertilizer is fertilizer whether it is applied dry or liquid. The amount of nitrogen applied per tree is what is critical. Liquid fertilizers applied to the foliage or short lived. Dry or liquid fertilizers applied to the soil last longer.

C. How many times per year and which month(s)?

Once per year is enough in the very early spring just before new growth or not long after it begins.

Watering, Mulching and Fertilizing Desert Landscapes

Q.  I have three questions. How often should I water? Do I need to put mulch around the plants and then cover them with rocks or keep the mulch exposed? Do I need to fertilize plants with a desert-type fertilizer or can I use the same stuff I use on my regular plants and how often?

 

A. How often to water. Winter; once every ten to 14 days. Spring until May 1^st; once a week. May 1 through the summer; twice a week. September 15 to December 1; once a week. These are approximate dates. Adjust with the weather.

Purple leaf plum mulched with wood mulch in a desert landscape of rock mulch. Wood mulch
adds organic matter back to the soil as it decomposes and is needed in soils around
some plants like purple leaf plum.

            Wood mulch is a substitute for rock mulch. Rock mulch will cause problems with some plants. If you want all rock mulch, then make sure the plants used can tolerate rock mulch. Wood mulch is used without rock mulch and should be three to four inches deep around plants.

Ammonium sulfate is a high nitrogen fertilizer containing 21% nitrogen (21-0-0)

            Fertilizers are the same for all plants. If you want growth, use high nitrogen fertilizers. If you want flowers and root growth, use a fertilizer with high phosphorus. Good fertilizers are more expensive than ordinary fertilizers and are frequently worth the money.

Sprint 138 iron contains iron in the chelate EDDHA
form which works very well in our highly alkaline soils

            If you can’t afford good fertilizers then make sure you use a good fertilizer at least once a year and use less expensive fertilizers the remainder. Use them when you can and the first application of the season is usually the best time to use them.

            One application per year is enough for most plants except lawns and plants that you appreciate for their flowers. In those cases four applications are best; Labor Day, Fourth of July, Memorial Day and Thanksgiving. If the plants are tender to winter cold, skip the last two fertilizers of the season.

            Plants that turn yellow are usually iron deficient and will need a GOOD iron fertilizer. Not all iron fertilizers work in our soils.

 

 

Eight Fruit Trees in a 10ft x 10 ft Space

Q. I have an easement in the backyard where I cannot plant trees. I have decided to plant as much as possible in the space I have left which is about an area 10x10. I would like to plant fruit trees in a high density there and keep the trees small for easier picking.

 

Multiple trees in a single hole about 18 inches apart. This provides a sequential harvest of
fruit from different varieties at different times of the year.

A. I would really caution you on a high density mini orchard unless you are truly committed to it. It will take more time and effort and require gaining some extra knowledge if you commit to any intensive gardening technique. If you are willing to spend a bit more time and effort (not a lot but the extra time is critical) then give it a shot.

            A 10x10 area is quite limiting but you could still probably get about 8 trees in there with a combination of multiple trees in a single hole and trellising them. You might consider planting fruit trees in a hedge with no space between the trees and letting them grow together.

Apples trellised along a fence on trellis wires about one foot from the fence and shade cloth protecting it from direct
sunlight from the south side of the fence.

            I personally wouldn’t plant any trees closer than about six to eight feet apart for a hedge or trellis. If you use apples or pears try to make sure they are on dwarfing rootstocks such as M111 for apples and OHxF333 for European pears.

            There really is no true dwarfing rootstocks for the stone fruits like peach, apricot or nectarine but the Citation rootstock may give you a little. These stone fruits are normally planted full size and kept small through aggressive winter and summer pruning.

            Another possibility instead of a hedgerow is trellising and I prefer it over hedging for small spacing. Trellising costs more because you have to construct the trellis but gives you more control of the plant and helps you keep it smaller.

What to Use on Vegetable Seedlings Decimated by Insects

Q. The day after I planted seedlings in my 4x8 raised bed I noticed they were decimated by some kind of insect. When I was amending the soil I noticed some small worm-like critters in the soil. I sprayed Bt but it evidently didn't do anything to help the situation. I was told to use a powder called "milky spore disease" to kill any grubs or grub-like insects in the soil. Have you ever heard of this product? They said it works and I only have to apply it one time. Can you advise me on this product and where I might find it or some other solution? 

Decimated pepper

 

A. The milky spore product only works on Japanese beetle and a few closely related insects which we do not have in southern Nevada. It is a bacterium and works rather slowly, if it will work at all, on pests we have in southern Nevada.

            Bt works differently. It works on those insects that mature or pupate into either moths or butterflies. So if the immature insect turns into a beetle for instance it will not work. So without knowing which insect is doing damage it is hard to know what will work.

Cutworm larva

 

            The other alternative is to use a conventional pesticide approved for use on vegetables and has insect grubs or larvae on the label. These insecticides leave a poisonous residue for longer-lasting insect control.

            This time of year Bt is a good product to use because it will control many of the insects causing damage right now. Look for products with a label that says Dipel or Thuricide. Forget the milky spore bacterium control in your case.

            I am sending you a picture of what the cutworm larva looks like and its adult form, a moth. I will also post it on my blog. Bt can be sprayed on the soil and left undisturbed (no hoeing or irrigating after the application) for a few days but you have to repeat your applications to get any long term control.

Corn earworm moth adult
http://ipm.illinois.edu/ifvn/volume15/frveg1506.html

            This is the time of year that moths are flying, mating, laying eggs and larvae are out looking for food. Usual cutworm damage is at the soil surface, not on the leaves.

Planting Two Cherries in a Single Hole to Save Space and Pollination

Q. I have two cherry trees and one needs to pollinate the other. Can I plant both trees in the same hole so save space?  The trees grow to 20 feet and I will keep them pruned to a smaller size.

Sweet cherries produced at the Orchard. Production is erratic in the Las Vegas Valley.

 

A. Yes, you can. Plant them about 18 inches apart, one on the east side and one on the west side of the hole. Try to pick varieties that are similar in vigor (how strong they grow) and on the same variety of rootstock.

Multiple apple trees planted in a single hole at Dave Wilson Nursery

            I will warn you that sweet cherries are squirrely in our hot desert environment. They produce cherries in some microenvironments and not in others. They usually seem to do better in backyards that are somewhat protected (no strong winds) and have a more humid environment during pollination.

            If you plant these two trees together, keep them occupying only half of the canopy. Do not let them compete with each other but keep them occupy their own, separate spaces. This means there will be a clear physical separation between the plants in their own half circle of canopy space. Also, do not let one get bigger than the other. Keep them pruned to a similar size.

            These cherries must also bloom at the same time if they are to pollinate one another. Check your pollination charts to make sure they are compatible.

Some Fertilizers Will Cause Staining

Q. I have a question regarding fertilizing.  My husband used a fertilizer that stained our pavers and the bottom of our pool in spots. Do you know of a solution to remove those stains?

A. The fertilizer most likely had iron sulfate in it. The spots would be dark reddish brown or brown. Muriatic acid would remove it. Be careful using it.

Iron spray staining grape berries. Be careful spraying iron on fruit vines and trees that have fruit on them if you
care about appearances.

            If it is in the bottom of the pool and water is in the pool there is not much you can do about that unless the pool was empty. The bag should have warned you, hopefully, to use a drop spreader if it was for a lawn.

Plants Need to be Placed in Outside Environments with Care

Q. Last Christmas a friend bought for me a tiny pine tree about 6" tall. It is now 2' tall and I need to transplant it. When is the best time of year to do this?

 

A. It is April and getting too late now. I would wait and plant it some time between mid-September and mid-October as temperatures are cooling. However, if you run the risk of losing it, plant it now.

            You don’t mention how you were growing it. If you were growing it inside, not outside, you will need to gradually bring it into the outside environment or it could go into shock. This is called plant acclimatization and requires about three weeks inside a garage or outside shade shelter and then planting it.

Black Spots on Watermelon Leaves Could Be Several Different Insects

Q. I have attempted to grow watermelons for the first time last summer and everything was looking good until it got hot. These tiny black specks appeared on the back of some of the leaves.  I was told it was aphids but they weren’t sure.  I hope you can see them clearly from the picture I've attached. Should I use insecticidal soap as recommended or something else? 

A. I tried to magnify the picture so I could see the black spots better. I was curious if these were in fact from insects or not. I could not see it clearly but whatever it was, it appeared that it was no longer a problem and the leaves seemed nice and healthy.

            Aphids are cool weather insects and so when the heat hit they should have disappeared. The big insect problems for you on watermelon would be aphids earlier in the season during cool weather, squash bugs shortly after planting and whiteflies (during the heat).

            Yellow sticky traps can provide a method to determine if whiteflies are a problem or not. I will post a short video on my blog on how to make these rather than buy them. They are handy to place in the garden for insect monitoring.

            Soap and water sprays are good but must be done about every three or four days and the underside of the leaves must be sprayed as well. Squash bugs are nasty and can be vacuumed or hand-picked or delay planting by seed until after June 1. If you are hand picking or vacuuming squash bugs then be diligent for about three or four weeks and keeping the plants cleaned off every couple of days by hand until mid-June to avoid most of the problems with this insect.

 

 

 

Thanks to Garry Pearson, Lead Greenhouse Managerat UC Davis CAES,
                Department of Vegetable Crops, during his presentations on greenhouses in Afghanistan.