Container Grown: Tomato Black Bottoms and Pepper Sunscald Prevention

Q. These are my first 2 vegetables this year. All the others comming along appear to be OK. If I take down the fence, will the chipmunks still cut down the tomato plants?

Blossom end rot of tomato

A. The tomato looks like blossom end rot which is a mineral deficiency usually enhanced with irregular or somehow uneven applications of water. Watch your watering frequencies and if you can make sure your soil is enhanced with compost at the time of planting and use a surface mulch such as straw once they start blooming.

Sunscald of pepper

On the pepper this looks more like sunscald on the fruits. This is poor canopy development to shade the fruits and  having these fruits exposed to our extremely high sunlight intensities. You have two options. One is to focus on getting better canopy development through the use of fertilizers and soil improvement on a regular basis or grow them under about 30% shade. 

Those little varmints will eat the fruits of tomatoes and peppers. You need to keep the veggies fenced or get on a program of varmint suppression or control. A good product for this is a bait called Quintox and can be used under certified organic operations. However you should follow the directions for baiting quite closely which starts at the beginning of the season. There is a movement on to protect the Mojave ground squirrel but I do not believe the Antelope ground squirrel is protected or there is a movement to protect it.

Controlling ground squirrels

Antelope ground squirrel

Another thing you should keep in mind. You are growing these plants above ground in black plastic containers. I could see them in your pictures before I cropped them. These containers, exposed to our sunlight, will generate surface temperatures on the containers of 170F. I have measured them with an infrared gun. Plant proteins begin to denature at 140F. You will kill significant numbers of roots with this kind of heat transferred to the soil inside the containers.

Pepper pic before cropping.
I could see the top of the black plastic container.

Two things you need to do with containers in our climate. Use double-potted containers. One container nested inside an outside container will take some of the heat from being transferred to the soil. Or plant the containers in the soil still using a double pot. This is actually best.

Secondly, irrigate about 9 am just before temperatures begin so soar. This will make sure the soil is wet going into the heat of the day. Wet soil can absorb alot more heat than a drier soil.

Pecan Trees Not The Best Choice for Edible Desert Landcaping

Q. I would like to plant a pecan tree in my backyard but some friends told me they are so difficult to maintain plus they need to be close to another one to be pollinated. If I can plant a pecan tree which do you recommend to plant for some shade and nuts?

A. Pecan trees will do well in this climate but I would not recommend them as a shade tree in the desert. Pecan trees can be monsters in size and spread and, because of their size, require very large amounts of water as they mature. They are not well suited to a desert climate where water is a premium.

For shade, all you need are trees in the 20 to 30 foot range in height and they will use considerably less water. If you want a nut tree then pick an almond or pistachio instead. If you are concerned about shading a home for energy conservation, then select trees and shrubs which shade the south and west walls, not the roof. This is where you’re going to get the most energy conservation.

But if you must have a pecan, try this website for selecting the variety you want.
Pecan Selection from Dave Wilson Nursery

Since these may be hard to find in Las Vegas you can try ordering online this winter for early spring delivery.
Bay Laurel Nursery bareroot nut trees

Does Your Compost or Garden Feel Kind of Grubby?

Q. Recently I discovered some white round worms or grubs in my soil when I was planting. What are they and what can I do to get rid of them? Will they feed on the roots of the plants and kill them? Do you have any idea where they came from?

Open publication - Free publishing - More insect control

Grubs found in compost

A. It is hard to tell without seeing what they actually are. There are some grubs which have six legs on the front and are grayish white which we see a lot of in decaying organic matter. They It is hard to tell without seeing what they actually are.

There are some grubs which have six legs on the fun and are grayish white which we see a lot of in decaying organic matter. They can also feed on the roots of some plants usually herbaceous plants like vegetables and herbs flowers and that kind of thing. These are frequently larvae of beetles rather than moths. And because they are larvae of beetles they will not be controlled by a very many organic chemicals.

If plants are present than you can use a soil insecticide drench of things like pyrethrum or a heart are pesticide such as Sevin as a liquid drench. If the soil does not have plants than you can loosen the soil, moisten the soil, cover it with plastic and let it cook and the sun making sure that the edges of the plastic or sealed tightly to the ground so that they do not escape. By now they probably have stopped feeding and have pupated, turning into adult beetles and will emerge to mate with other adults. By this time there feeding damage has probably stopped.

After mating the female then lays eggs in well prepared garden soils or compost where the young hatch and feed on decaying organic matter and soft tender roots of plants. I hope this helps. Above is a picture of one of the grubs I’m talking about.

And because they are larvae of beetles you will not have as many organic controls available to you. If plants are present then you can use a soil insecticide drench. Things like pyrethrum, an organic pesticide, or a hard pesticide such as Sevin can frequently be found as a liquid drench.

If your soil does not have plants then you can loosen the soil with a spade, moisten it, cover it with plastic and let it cook in the sun making sure that the edges of the plastic or sealed tightly to the ground so that the heat does not escape. This is called soil solarization.

Green june beetle on kadota fig

By now they probably have stopped feeding and have pupated, turning into adult beetles and will emerge to mate with other adults during this summer. By this time their feeding damage has probably stopped.

After mating the female then lays eggs in well prepared garden soils or compost where the young hatch and feed on decaying organic matter and soft tender roots of plants. Readers of my newsletter and blog will see what this grub looks like and get more information.

No Pain Compost Pile and the Las Vegas Waterbug (Cockroach)

Q. I would like to start a compost pile if it is not a back killer turning it. Any suggestions on how to get started so I don't have to return to trashing my kitchen garbage and coffee grounds? We also have tons of cockroaches and wondering what organic gardeners are doing to get rid of them.

Compost piles at The Orchard
http://www.facebook.com/pages/Master-Gardeners-Tree-Fruit-Orchard/117996858226695

A. Cockroaches are decomposers. They are out there looking for food that they can eat and, in the process, eating aids in their food breaking down and decomposing. The problem is that they do not distinguish between “their food” and “our food” so it is important to keep compost piles as far away from where we live as possible.

It is also important to try and keep an open area between the house and the compost pile where they can be pounced on by predators such as birds, lizards, wasps and even cats.

Stale beer works well as an organic control as it does also with slugs and snails. No, I own no stock in beer companies. You can make a bait station that they cannot crawl out of by using a slippery sided steep container with a bait such as stale beer, coffee grounds, vanilla or human food scraps containing sugar or fat combined with an inch of water for drowning them. They have to be cleaned out regularly.

Diatomaceous earth works well as long as it stays dry as does boric acid powder. This can be placed on the outside of the home at possible points of entry. Leaking water serves as an attractant such as irrigation boxes and laundry rooms with washing machines or hoses that leak.

Don’t keep wet sources of water close to the house or, if an irrigation box is continuously wet, then get it fixed and in this case important in reducing cockroach populations.

Wash containers before putting them in the trash. Wash garbage containers frequently to eliminate possible “their food”. Finally there are chemical sprays that are quite effective sprayed in an area where the house meets the ground and sealing any possible holes or cracks where they can enter.

Use chemicals as a last resort in pest control.

Bare Naked Peach and Apple Shoots and Summer Pruning

Q. About 15 years or so ago, I read about fruit trees that have limbs that are bare for 18 - 24 inches before new stems and leaves come out. I have forgotten what the cause is and what the prevention or cure is. I presently have a peach tree with this condition and wonder how I could have prevented it or can cure it.

A. This can be a complicated area and it depends on what you might be referring to on the tree. If you are referring to fruit trees with new growth that has normal vigor but without the development of leaves along its length, these can be referred to as “blind shoots” or “blind wood”. Older thought used to say it was due to a lack of winter cold weather or a lack of “winter chilling”. Some are questioning whether this is true or not.

Blind wood in apple

If you are referring to new growth that is excessively long and vigorous but lacks side branches then this can be excessively vigorous growth that could be handled through summer pruning.

If I want to keep a tree small, I try to summer prune as much as I can every late spring and early summer. This helps to control tree size and keeps them smaller and more manageable.

Summer pruning is only pruning growth that has developed since spring. Growth older than this is not pruned until winter dormancy.

Starting about in April in our climate I begin the summer pruning process at The Orchard. The first growth that I remove is growth that is not worth keeping. These are vigorous shoots that grow straight up, straight down or toward the center of the canopy. Remove these at their point of origin. Once these unproductive branches are removed I then focus on shoots that I plan to keep or at least until I can see them better when the leaves drop this winter.

Remember the most productive branches grow in the canopy at about a 45 degree angle above horizontal.

Watersprouts in apple should be removed

Any shoots that have grown longer than about 24 inches in length since spring are cut back to about 18 inches in length. I know yours is a peach in your case but on fruit trees that produce fruiting spurs along their branches (think short side shoots that produce fruit like in apples, pears, plums, apricots) cutting them back sometime between April and June will encourage earlier fruiting along these branches. Cutting these excessively long branches so they are shorter will force fruit to be produced closer to the ground where it can be harvested easier.

Most peach and nectarines do not produce spurs for bearing their fruit. They bear their fruit along the length of one-year-old branches. Do not allow this year’s new growth to become excessively long.

Apple spur (short compressed shoot) supporting fruit

In your peach tree’s case, if branches are growing straight up, straight down or toward the center, remove them at their source. If new growth is growing excessively long, either remove them (if growing straight up, straight down or toward the center) or cut them back to 18 inches in length if they look like they will be productive in the future.

Is Bagrada Bug or African Painted Bug (Bagrada hilaris) in Southern Nevada?

A good series of pictures of this insect can be found published online by the University of California Riverside at http://cisr.ucr.edu/bagrada_bug.html
 
Here is Arizona's information.

Open publication - Free publishing - More bagrada bug

Wormy Corn is a Problem



Corn earworm thanks to
Michigan State University

Q. My corn is 3-4 ft high and has ears on it already. According to "the book", I shouldn't be harvesting until mid June by the 'days to harvest' guide. The ears are about half formed. The silks have turned dry and brown, which is when they should be harvested. I pulled one off to see what is going on inside, and it is forming, but I found an ugly green worm about 3/4" long. Is that an army cutworm? I thought they were brown, as that looks like what is feeding on my Lantana. Yuck!

A. You may have planted your corn a bit too late in the season and this may have been because of cold spring weather. This was not a good spring for corn because of the cold weather. In fact, it was not a good spring for many vegetables that prefer heat unless you had a nice warm microclimate for your vegetable garden. The cool spring vegetables were fabulous!

You can try a fall crop of corn by planting the seed around the middle of July or the first part of August. One other reason the corn may have been short is a lack of water. If they were stricken with drought they will not get to their full size but try to produce ears on shorter plants.


Corn showing signs of drought and lack of nitrogen

The insect you describe is corn ear worm. As your corn plant begins to silk or produce those soft silky filaments out of the ends of the young years then you must begin to apply an insecticide to prevent ear worms from damaging the ears. The insecticide can range from oils to Bt or spinosad to a hard insecticide such as Sevin.

Corn showing signs of drought and lack of nitrogen

The insect on your lantana was probably tobacco budworm. Bt or spinosad will work great on these grubs or larvae as well.

Some Fall Bulbs Will Need Extra Chilling

Q. Could offer any advice on what to do to keep my spring bulbs (tulips and hyacinths) healthy so that they bloom again next year?  I bought them this past fall and kept them in the refrigerator for six weeks or so, and then planted them.  They came up and bloomed beautifully.  Should I dig them up when all of the foliage has died off of them and store them again in a cool place until next fall?  Will they survive if I leave them in the ground over our hot summer?

A. Both tulips and hyacinths are considered fall bulbs. Fall bulbs should be planted in late summer and fall. Besides tulips and hyacinths other fall ball does include crocus, narcissus, and ranunculus. October, November and December are the months to plant fall bulbs.

You must work the soil well with compost and some sort of phosphorus fertilizer such as bone meal. Plant the bulbs twice their diameter. If your soil is sandy then you can plant deeper than this. Make sure they are mulched and receive periodic Irrigations during the winter to keep them from drying out.

Remember that after the flower fades the bulb is making its flower bud for next year so try to keep the foliage green as long as you can. Don’t cut off the foliage. You can pick the flowers and use them for arrangements if you like or gifts. That will not affect next year’s bulbs but try not to remove the foliage as much as possible.

Anemones and ranunculus can be planted as early as October. Tulips, hyacinths and daffodils should spend six weeks in the crisper drawer of the refrigerator and planted in late November or December after soils have cooled. This pre chilling simulates winter temperatures and blooms will be bigger and brighter.

Don’t forget to try gladiolas. They do well here. Grape Hyacinth or muscari performs year after year with very little care. They might last as long as five years. Go ahead and scatter them under shrubs and trees alike. They are nice for arrangements and last for days.

Never Give a Slug a Beer

Q. I am thinking how expensive it is to keep the slugs in beer. Can you tell me if I am the only one with slugs?  I have lived here 22 years and bought plants from Plant World, Star, etc., know they could come in that way and multiply...grrr

A. I had to go looking for an answer other than beer and found an interesting answer on a website at http://www.plantea.com/slug-baits-coffee.htm 

Strike up a conversation between people who garden in "cool" climates and within moments the word "slugs" will pop up. It's enough to shift a casual chit-chat into a strategic planning session.

Gardeners agree that slugs are a menace, but they are often confused about which tactics to employ. While Picking slugs is one of the most effective methods to reduce the adult breeding population, sometimes in the heat of the battle you need to attack on more than one front. Here's the scoop on slug baits, including a different twist on the war against garden mollusks: Coffee.

Many commercial slug and snail baits are available today as pellets, meal, or emulsions. The two most popular baits that are currently licensed and formulated into baits for use on home gardens are:

+ Metaldehyde

+ Iron phosphate

The hazards of metaldehyde
Most chemical baits combine an attractant, usually apple meal or some other sweet-smelling base (more on that later) with an active chemical compound such as metaldehyde, to poison whatever swallows the bait. Products containing varying concentrations of metaldehyde include: Cory's Slug and Snail Death, Deadline, and Slug-Tox.

Metaldehyde, which has been used since the 1930's, works by dehydrating its victims. These products are sold as granules, sprays, dusts, pelleted grain or bait. They are usually applied to the ground around plants to attract and kill slugs and snails.

Toxic to birds, dogs, cats, humans...

Metaldehyde is classified by the U.S. Environmental Protection Agency (EPA) as a "slightly toxic compound that may be fatal to dogs or other pets if eaten." Many vets have experience with dogs ingesting metaldehyde baits.

According to the Field Guide to the Slug (Sasquatch Books) ingested metaldehyde can lead to nervous system damage or death in humans and other animals."The threshold for tolerance is related to size, making birds and small mammals especially vulnerable." Bottom line: if you decide to use poison baits, do so with extreme caution, especially about edible plants, and READ THE LABEL.

Now let's take a look at two chemical-free alternatives:

Iron phosphate bait
Iron phosphate slug and snail baits are much different than chemical warfare. For one thing, iron phosphate is a compound that occurs naturally in the soil.

Products containing iron phosphate include: Sluggo and Escar-Go! (available through GardensAlive!). Iron phosphate products are a pelleted bait, that resembles grains of rice. They're a blend of iron phosphate (the "active ingredient") which is then coated with an attractant (bait). Slugs and snails are attracted to the bait more so than plant (I've witnessed this personally!), even luring them from their hiding places.

According to one set of instructions, this is how a product like Sluggo works. "Ingestion, even in small amounts, will cause them to cease feeding." Or, as one gardener-friend put it, "They crawl away and die, and you never see them again."

Unlike Deadline, Sluggo granules can be used around domestic animals and wildlife. It stays intact for a week or two, even after waterings or several rains, and provides protection to greenhouse plants, container gardens, vegetables, flowers and fruiting plants and shrubs. Manufacturers of iron phosphate baits claim they are non-toxic around children and pets, and are much safer to use than those baits containing metaldehyde.

SKIP THE SALT
Many gardeners have sprinkled a dash of salt on a slug at least once. This is not a good thing, as the salt can make the soil toic to all but a few salt tolerant creatures and plants.

Do the java-jive against slugs
According to Nature magazine, we have another weapon in the eternal battle against slugs and snails: the double espresso. Slugs and snails hate caffeine, researchers have discovered. The chemical could become an environmentally acceptable pesticide.

Robert Hollingsworth of the United States Department of Agriculture's Agricultural Research Service in Hilo, Hawaii, and his colleagues were testing caffeine sprays against the coqui frog, an introduced species that infests potted plants.

They also noticed that a 1 to 2 percent caffeine solution killed nearly all the slugs and snails within two days. Concentrations as low as 0.01 percent put the pests off their dinner. A cup of instant coffee contains about 0.05 percent caffeine, and brewed coffee has more.

This sounds like scientists chatting around the water cooler, so let's look at a more real-life example: A cup of drip brewed coffee has about 115 milligrams of caffeine, an espresso (and percolated coffee) about 80mg, while instant coffee has about 65mg of caffeine. Thus, drip brewed coffee is about twice as strong as the instant stuff, which means you want to use drip brewed coffee for repelling slugs and snails.

Coffee grounds are already recommended as a home remedy for keeping slugs and snails at bay. Grounds repel slugs, Hollingsworth found, but a caffeine solution is much more effective, he says: "Slugs turn back immediately after contacting the [caffeinated soil]."

Personally, I've had good results (if you want to call making a slug uncomfortable "good results") with sprinkling coffee grounds around plants as well as spraying slugs with brewed coffee--you know, the stuff that doesn't get consumed in the morning and tastes really bad when you try to microwave it in the afternoon? Many other gardeners have told me they've had similar luck.

How does caffeine repel slugs and snail?

Well, caffeine is an alkaloid compound that acts as a stimulant in humans. Alkaloids are usually derivatives of amino acids and most alkaloids have a very bitter taste. Just think about your first taste of coffee. Pretty bitter, wasn't it? Caffeine is found in the beans, leaves, and fruit of over 60 plants, where it acts as a natural pesticide that paralyzes and kills certain insects feeding on the plants.

Bottom line: caffeine is more effective against slugs than metaldehyde products. The United tates bans metaldehyde residues in food, but classifies caffeine as safe. It may even qualify as organic, adds Hollingsworth. "I would expect caffeine applications to kill small snails and slugs, and repel the larger ones," says Hollingsworth. He envisions it being used in greenhouses and on fruit and vegetable crops.

Thank you, Marion!

Spider Mites Can Be Controlled

Spider Mite Damage But Obviously Not Tomato.
What to look for? Yellow speckling or stipuling,
dusty appearance on the leaves, webbing may or may
not be present.

Q. I am hoping that you can help me, to help my son. He lives in southern California, with a young family. In order to make ends meet, he has created a good size garden for his family, to have fresh vegetables. Some of his tomatoes are getting ready to be harvest, but his crops are being plagued by spider mites. He has released a large amount of lady bugs, from his local nursery, but they don't seem to be solving the problem. Is there something that he can treat his crops with, that will not contaminate the vegetables? Please give me some "fatherly advice" for him.

A. When your son purchases transplants in the future try to find a supplier who is growing them by using only organic pesticides. Some growers will spray transplants with a hard pesticide to knock everything down before shipping them out. This way they get to market looking pristine and with few insect problems.

The problem with this approach is that spider mites are controlled by other insects and predatory spider mites. Once these predators are killed any new infestation of spider mites takes off like a rocket since they reproduce so quickly and their predators are gone.

Spider mite population explosions are enhanced if plants are covered in dust. Wash them periodically, particularly after a wind may have covered the leaves in dust. As far as chemical controls of an organic nature try the use of insecticidal soaps or horticultural oils or perhaps both.

I have heard some recommendations that include the use of Neem oil but people are recommending mixing a soap or detergent with the Neem oil. No, no, no. You must never mix a surfactant or any kind of soap or detergent with oils. This destroys the basic property of an oil that kills insects; namely suffocation. Use both of them, but use them separately or alternate their use.

Insecticidal soaps must be applied every 3 to 4 days or no more often than the label recommends but spray to include the undersides of the leaves for any chemical control to be effective. Never spray in the hot times of the day but only very early in the morning or late at dusk when bees have returned to their homes. Bees will succomb to these sprays. I hope this helps your fatherly advice.

Squash Fails to Fruit Without Active Bees

Summer Squash Failing to Fruit Due to Lack of Pollination. Photo by reader.

Q. I have had great success growing both yellow and green squash in my garden for the past five or six years.  Last month I harvested about ten nice pieces, but in the past couple of weeks they have all been turning very hard and the yellow pieces have turned dark and almost orange.  I have attached a couple of pictures of both the fruit and the plants.  Please let me know if you any suggestions.
 

A. Your summer squash looks nice. You will get more blemish free fruits with twice to three times a week sprays of insecticidal soaps including spraying the undersides of the leaves. The lack of squash development is due to poor pollination most likely due to cool weather and poor bee activity.

You can attract more bees to the area by planting plants that bees love and flower at the times your vegetable garden needs pollination. Bee loving plants include many of the herbs which are allowed to flower. These might include rosemary, basil, lavender, oregano and thyme to name a few. Woody ornamental plants typically flower for short periods of time but there are some like Texas Ranger, brooms like Scotch broom, lantana, verbena, and others. Go to your nursery and see what is in bloom, particularly reds, purples, pinks and start planting.

Some gardeners like to hand pollinate squash for better setting of fruit or if you want to save seed from certain squash for planting next year. If you want to save seed and you don't prevent contamination from other melons or squash then your seed will not come true. Here is a video on hand pollinating squash and some great background on this family of vegetables.

http://www.youtube.com/watch?v=6ay4smh2FfQ&feature=related

Deadly Pillbugs Strike Again

Q. I have voracious pill bugs eating my tomato plants (starting at the stalk at ground level).  These are the bugs that resemble armadillos and can roll themselves into a ball.  Is there anything I can do to protect the plants or get rid of the bugs?

Pillbugs. Thanks Texas A and M University!

A. If they roll into a ball then they are considered pillbugs. The pillbugs or sowbugs, even though they do help in the decomposition of dead plants into organic matter, will damage soft fruit and other soft plants. Particularly if there are large numbers.

They like to congregate under boards, cardboard, rocks and other flat surfaces that stay moist and have plenty of air. Sometimes you can lay out boards or cardboard and let them congregate under the surfaces and then scoop them up and get rid of them. You can also put out semi rotten tomatoes or other vegetables which will act like magnets and attract these varmints. Then you can scoop up these rotting fruits and vegetables along with the pillbugs and dispose of them. That won't get rid of them but it will take the numbers down.

You can protect the plants with cardboard collars such as the inside tubes in toilet tissue, spray the soil surface around young plants with pyrethrum or dust with diatomaceous earth.

Apply Insecticidal Soaps Frequently for Effective Control of Garden Insects

To protect vegetable and herb plants from chewing insects you should be spreading with an insecticidal soap every 3 to 4 days. Insecticidal soaps can be purchased or made at home using 2 ½ tablespoons of a liquid detergent such as unscented Ivory liquid, Amway or Dr. Bronners in a gallon of water. However, insecticidal soaps are expressly manufactured for this purpose and are preferred.

Insecticidal Soap

Don’t use liquid detergents with additives such as scents or hand conditioners. This spray must come in contact with the insects. Make sure you spray on the undersides of the leaves and stems where most of the insects party. Any residue left behind does not do very much. Spray when bees are not present and don’t spray plants that are in bloom unless it is at sunrise or sunset since it is also lethal to bees.

Dr Bronners Peppermint Soap

Mulching, Staking and Painting Important to New Fruit Trees in the Hot Desert

Mulch Applied to New Fruit Trees With Growth Difference In One Season

If you planted fruit trees this spring please apply 3 to 4 inches of course wood mulch, not bark mulch, around the trees a distance of 3 to 4 feet from the trunk. You must keep the wood mulch away from the trunk but distance of 6 inches so the trunk does not rot at the base. After the tree is 3 to 4 years old and the trunk is mature with bark you cannot allow the wood mulch to lie against it.

After these very high winds you can see the wisdom in securely staking newly planted trees in our climate. Stakes should be removed if possible after the first, full growing season.

These young fruit trees need to be protected from our high intensity, desert sunlight for the first few years of growth. I would not recommend a protective wrapping around the trunk as this can actually create higher temperatures than just leaving it uncovered. You can use flat boards if you choose on the west or south sides of the trunk but it may be easier to paint the tree trunk and lower limbs with dilute, white latex paint.

Diluted White Latex Paint Applied to Peach Tree to Help Prevent Sunburn in Hot Desert Climates

Make sure the paint is latex and make sure it is diluted to at least a 50/50 mixture with water. You can use more water than this as long as painting the tree results in a much lighter surface that will reflect sunlight and help to keep the surface of the plant cooler than unprotected surfaces.

Paint all surfaces of the young tree which would be exposed to direct sunlight. Most importantly paint the south, west and northwest sides of the trunk as well as the upper surfaces of major limbs or scaffolds. Reducing the sunburning of juvenile woody plants will help to minimize attacks by boring insects.

Stop Cutting Asparagus Now

Asparagus Ferns - Asparagus Uncut

The asparagus harvest season is almost over and you should begin to not cut anymore spears and allow your spears of asparagus to grow and feather out as soon as it gets hot.  It is important to feed your asparagus as it ferns out to help it rebuild its crowns for next season’s crop.  You should add a high phosphorus fertilizer of your choice along with compost or light monthly applications of a high grade of fertilizer.

Control Peach Twig Borer Now

Peach twig borers are flying now and some are getting into early maturing peaches, nectarines and apricots. These small, brown flying months cause some slight damage to new growth in these trees and cause wormy fruit. 

Damage to New Growth of Peach Due to Peach Twig Borer

They usually enter the stem end of the fruit where you can see some frass or light brown grounds left behind by the larva or worm.

Peach Twig Borer Frass Near Stem End on Apricot

 These can be easily controlled with sprays of either spinosad or Bt, both of which are organic sprays. Follow label directions and apply regularly. Add a surfactant such as a spreader/sticker or small amount of unscented liquid detergent. Spray the entire tree, particularly the fruit. 

Peach Twig Borer Larva Causing Wormy Peaches




Spinosad by Ferti-Loam



Spinosad by Monterey

Windy Weather Means Irrigating a Bit Sooner

The past few days have been unusually windy.  In fact, this entire spring has been a windier year than normal.  The saving grace is that it is unusually cool for this time of year.  Normally I would be irrigating immediately following strong winds such as we had.  If the plants were on drip irrigation I might even be irrigating during the heavy winds.

There are four factors which are the primary driving forces behind the use of water by plants.  The two which are most responsible are wind and bright, continuous light or light intensity.  The other two, temperature and humidity, are also important and increasing temperature nearly always accompanies increasing light intensity.  Bright days nearly always indicate warmer days regardless of whether it is winter or summer.

Why is this important to know?  Daily changes in the weather are what I use to fine tune my irrigations from week to week.  For example if my normal days to irrigate in May are on Tuesdays and Saturdays and my plants just went through some horrendous winds on Saturday and Sunday I might irrigate the day after the heavy winds.  So instead of waiting until Tuesday I might elect to irrigate one day earlier (or even during windy weather if everything is being drip irrigated). 

Late next month in June is a time normally when temperatures start approaching or exceeding 110° F.  As we begin to break 110° F on a regular basis, I will consider adjusting our irrigations of deep rooted plants like trees and shrubs to three times a week instead of two. 

However, if weather stays relatively cool I might keep irrigations to twice a week unless there are strong winds which will substantially increase the use of water by plants.  High temperatures and gusty winds always drives water use up and should make you consider running an early irrigation cycle if you are permitted.

Fruit Tree Recommendations for Southern Nevada Download

Fruit Tree Recommendations for Southern Nevada -

Butterfly Iris Can and Should be Divided Every Few Years to Keep Them Blooming

Q. We have nine, 12-yr old butterfly irises is 3 groups of 3 that have outgrown their locations. They have grown/spread from their centers to become about 2 ft. in diameter and now only develop little new growth at their perimeters. I've attempted to prune them back by removing their dead center growth hoping that they will regrow from the center but to no avail. I'd like to replace them with some colorful, attractive ornamental grasses that do not grow taller than 3 ft. and don't spread like the irises.

A. I would keep the butterfly iris and just dig them this fall, divide them and replant them. Sometimes called Spuria or Spuria iris, these are some of the best iris for our desert climate and can be quite showy if managed properly. They must be divided regularly.
Some of the spurias originate out of Persia and Afghanistan. Many of these varieties like the high temperatures and dry humidities of the desert but not our infertile soils. They will perform best if they get some relief from late afternoon sun but should be in full sun most of the day.

They do not like rock mulch at all and should never be planted in rock mulch. Always use wood chips (not bark) mulch of two to three inches as a surface mulch to enrich the soil and keep it moist. They must be dug every three to four years and divided to perform well.
And they must be fed regularly as they are heavy feeders during the growing months. This can be done by applying regular fertilizers regularly or using slow release types less often. Fertilize during the bloom period with formulations of Osmocote, Peters or Miracle Gro for flowers.

Divide them with a sharp, sterile knife, cutting the rhizomes at a bud and allowing the rhizomes to heal for a couple of days. Or you can dust them with a fungicide after they are cut. Throw out any rhizomes that do not appear healthy or robust looking. Plant these divided rhizomes about two to three feet apart for solid stands in the future.

Since these iris (depending on the variety) can range in height up to four feet it is best if they are used toward the back of the planting area. When planting or replanting the soil should be reworked with about half compost by volume and add treble super phosphate to the planting mix if you want good bloomers.

Slugs LOVE Stale Beer

Slug

Q. I have learned about slugs two years ago and thought I won the battle. I notice my marigold plants are withering. Went out at night with flashlight and YES!!! Found some big fat ones. The next day lifted a decorative plaque which is on the ground and I got the whole army and their children. Horrible. So I am squishing again and putting the snail dry stuff I got from store. I read about beer and wonder if I should do that. Any suggestions?

A. Stale beer works great as a slug bait. Put out a bowl of day old beer in the garden, sinking it slightly so they can get entrance and they die a happy death. Cover it with some cardboard to give them a place to party. You must clean out the former partiers and replenish the keggers frequently.

Converting Gallons to Minutes for Irrigation

Q. Could you tell me where I could find irrigation instructions in gallons rather than hours and minutes? I am having difficulty in calculating how much to irrigate larger established plants and trees.




PET Table for Las Vegas; Months Correspond to 1=January and 12=December, Inches of Water Per Day

 A. No one puts it in gallons because there are too many different manufacturers and rates of deliveries of different irrigation emitters and sprinklers. These can vary from 1/4 gallon per hour (1 liter) to five gallons per hour. Then there are the types that are variable and can be twisted open to give you more or fewer gallons per hour.

You have to figure make the conversion and convert it yourself. It is not terribly hard to do, particularly in drip irrigation. Each emitter is labeled or color coded to the gallons per hour that they emit.


Drip Emitters Color Coded to How Many Gallons Per Hour They Emit

The hardest emitters to figure out are the types that can be adjusted to different amounts of water. Many of these are adjustable between 0 (shut off) to 10 gallons per hour. It seems simple. You just twist the emitter open and it delivers more gallons per hour. But in actuality it begins to defeat the purpose of drip emitters: precision.

Also many of these variable flow emitters are not pressure compensated. If it is not pressure compensated, then opening one emitter and allowing more gallons to flow can affect the number of gallons on all the other non pressure compensated emitters on the same line. This can mean you have to twist open or twist close each emitter along the same line perhaps multiple times to get the flow that seems to be appropriate.

Not only that but these variable output emitters frequently emit so much water so quickly at the higher settings that it results in water puddling and running off to low spots. This is exactly contrary to the reason we should use drip emitters.



Drip Emitters are Precision Applicators of Water

 With many different types and sizes of plants along the same line the next difficulty for most people is to figure out what size (gallons per hour) to match up with each plant along the line.

So this is how I do that. The first thing I do with an emitter line attached to a single valve is determine how many hours or minutes the valve will be left open for watering. Frequently for drip irrigation the shortest time is one hour.

"Yikes" you might say because most people want to irrigate fifteen or twenty minutes. The problem with these short irrigation times is that it may force you to use the variable output emitters. Or it results in water applied so rapidly it does not penetrate the ground and instead runs and puddles somewhere else.

Start with a minimum of one hour. In some cases you might water for two or three hours on a single line. What difference does it make? You are not standing there with a hose and it can take all night if you want it to.

There is no problem watering at night with drip irrigation. Let it soak long, slowly and deeply. Try to use at least two emitters per plant in case one plugs. Distribute the emitters under the plant canopy, one foot from the plant with distribution tubing and secure them in place with rock mulch or stakes to hold them in place. Emitters should be above the mulch so you can check them for plugging. Plants that are spaced closely together can and will get water from each other.

Lantana Froze to the Ground

Q. This winter I had a low temp of 25° F at my house. So far I have a couple of sprigs coming out of two cut back Lantana and four with no sign of life. What's lantana's low temp tolerance?

Freeze Damage to Bougainvillea

A. It is not just simply a matter of what the low temperature was. Plant losses due to freezing temperatures involves how low the temperature got, the time of year low temperatures occurred and for how long or how many hours. Relatively mild freezing temperatures can cause considerable damage if they occur early in the fall or late in the spring.

Also, 25° F can be much more damaging if it lasts for 1 hour vs. lasting for 15 minutes just before sunrise. On top of this, freezing temperatures accompanied by strong winds will be much more devastating.

You should have seen some new growth coming from the base of the plants by now. If not, you will have to replace them. This winter was hard on lantana and, in some locations, they did freeze out or severely die back.

In the future, you should be able to cut them back to 2 to 3 inches in height and they will come back nicely. Don’t forget to fertilize with a good quality fertilizer that encourages flowering such as a rose fertilizer, tomato fertilizer, fruit tree fertilizer, etc.

Almonds Turning Yellow and Dropping

Almond Nut Sap Oozing and Dropping

Q. I'm having an awful time with my almond trees. I have two and they are about 8 years old. Last year my tree had large almonds and was just covered with nuts. Well, I lost all of them. They have a see through something coming out of them and then they open and have this yellowish design on the inside. Then they drop. In the meantime my almonds are falling off. So far this year I applied Volck Oil Spray when they were dormant and two weeks ago I applied a fungicide.

A. Thanks for your pictures. Several people have visited with me about the same problem. The squiggly resin coming from the nuts is usually a sign of feeding damage by insects which have mouthparts like a hypodermic needle. They stick this needle into the skin of the nut or fruit, feed on the sap and withdraw it. When they withdraw the needle it leaves a hole in the skin and sap comes out and dries in the squiggly clear resin that you see.


Leaffooted Plant Bug


Sometimes the feeding damage by these insects can cause the nut or kernel not to form. This can result in husks with no nut and the almond yellows and falls from the tree. If this happens to a few nuts and hundreds still remain on the tree then it’s no big deal. But if this happens to hundreds of nuts then this is a big deal.

One of the culprits is the leaf footed plant bug or one of its relatives and you should keep an eye out for this pest. It is a bad one.

Another possibility could be a lack of pollination due to low temperatures during flowering or a lack of good fruit set. We did have some late freezes and if the flowers were open during freezing temperatures it might be possible they were damaged and you lost some of your crop. I do not believe you needed a fungicide spray. My strongest hunch is an insect problem if this happened to you two years in a row.

Asparagus Not Coming Up in Third Year

Asparagus Started From Seed in a Trench

Q. I had an 8' x 1' garden box patch of asparagus which this year would have been the 3rd year of growth. Everything was fine the first 2 years but nothing grew this year. I pulled up several roots and noticed they are like straw - empty in the middle. I do not think I overwatered. The only thing I did different was I started emptying my daily coffee grinds in the garden patch. Do you have any idea what happened or was the cause?

A. The coffee grounds would not have made any great difference either way. Asparagus can be planted from crowns or seed. I have had great luck both ways and particularly like starting asparagus from seed.

We use an irrigation trencher and set it at its deepest setting, usually about 18 inches deep. We then backfill the trench about 8 to 10 inches with heavily amended soil from the trench, minus large rocks. The soil taken from the trench is heavily amended with compost made from animal manure, in our case horse manure.

This compost is left to finish composting for about 4 to 6 months. This means this mixture of manure and plant waste is turned regularly and watered so that everything breaks down together. This finished or nearly finished compost is added to the soil removed from the trench in a mixture of about 3 to 1, compost to soil.

This compost/soil mixture is then added to the trench as I stated above. On top of this layer we will spread a high phosphorus fertilizer such as triple super phosphate to enhance root development. We will spread about one hand full of this phosphorus fertilizer every 3 to 4 feet in the trench.

Asparagus crowns are then placed in the trench and covered with amended soil from the trench. This is usually about a 50/50 mixture of compost and soil minus large rocks. If you leave large rocks in the trench above the crown it can cause crooked spears.

It is important to dig the trench or bed much deeper than the crowns or you will create perched water table just above the unamended soil. This perched water table can drown the asparagus crowns and cause them to rot.

From your description that is what it sounds like. I would be careful planting asparagus in that same location. I would find a new spot and dig a trench or bed much deeper than you need to for drainage.

Some Scarring of Apricot Probably Not Due to Thrips

Q. I have some damage to my apricot fruits and sent you a picture. Is this damage from thrips? I have a nectarine and an apricot tree. Once all the fruit is off the tree what is the best way treat the trees? From reading your newsletters I understand thrips are hard to eliminate. At this point I would even consider a non organic method. Not all the fruit was affected, but many with a minor markings. I removed and disposed all the fruit from the nectarine tree very early as all fruit was badly damaged.

Aprcot Scarring Sent from Reader

Wind, Not Insects, Causing Damage to Tender New Growth

Wind Damage to Persimmon

Q. I hope you can help with a small problem with our dwarf peach tree.  Something is shredding the leaves and I cannot see anything after a close inspection.  Could this be a nocturnal pest?

Root Weevil Damage

A. We have a lot of wind damage right now and that does shred leaves. The only other nocturnal insect might be root weevils which I have never seen on peach but “notches” the edge of the leaf, not shreds it. My best guess would be wind damage and not to worry about it. If you sent me a picture of the leaf I could tell better. You will be able to see the difference on my blogspot, Xtremehorticulture of the Desert, or my weekly newsletter.

Yucca Damage May Be Preventable With TLC



Damaged Yucca

Q. Any thoughts on what is going on with these plants? I think it is over watering and would like to know how much water and how often it should be watered in the summer and winter. They are on drip. Thanks.

A. The problem is that overwatering and underwatering and some other problems can have the same physical appearance. I would tend to agree with you that it is a watering problem most likely or a drainage problem where the water cannot freely drain from the roots.  I do not think it is an insect or disease pest problem.

These look like maybe either Spanish dagger, Spanish bayonette or recurved yucca. It is hard to tell from the picture. The leaves are heavily damaged with dieback and discoloration. I will post it on my blogspot because I have had others send to me similar pictures.

Yuccas can have some variability on where it is best suited for planting depending on the species. In some yucca they must be watered more often or put into less stressful locations than others. Some are more cold hardy than others. It is a bit hard to generalize unless we know which yucca it might be.

Closeup of Damaged Yucca

Bottom line, these should be watered deeply, not with trickles of water from an emitter. So about ten to 15 gallons each time you water. Then, depending on the species it might be as often as once a week in midsummer.

This is possible it might be a location problem depending on the yucca. If this is a hot spot in the yard with lots of reflected heat and light this might be a microclimate problem. Some of the yuccas are native to the Southeastern US and may be a bit sensitive to our soils and climate or microclimate if not protected. Don’t assume they are necessarily all desert plants and can be treated like many cacti native to the desert. They aren't.

I don’t like it that it appears to be growing in rock mulch. It might be all right but its tolerance to heat and dryness will be affected by the soil conditions as well. They are always a bit better off and more tolerant to stress if the soil is at least somewhat enriched. Even cacti like an improved soil and perform better!