Pyrethrin Spray Did Not Work on Leaf Footed Plant Bug

Q. I have not been able to get the leaf-footed plant bugs under control on my almond, pistachio and pomegranate trees. The nuts turn black inside. When the almonds first formed and still soft, I could see sap oozing where the bugs pierced the fruit. I have been spraying with pyrethrin until the weather got too warm. Someone recommended using diatomaceous earth on them.

Leaf footed plant bug not fully mature

A. If you search the Internet you will see all sorts of homemade remedies recommended by different people. These include diatomaceous earth, repelling them with garlic or hot pepper sprays, and even oils of mint and rosemary. The problem is they have no documented history of working.

            Until we have some definitive answers about what is working and not working and still safe enough for food crops, we are left with either trying products recommended on the Internet in a “trial by error” method or using products with a known history of success.

            I frequently look at the University of California IPM (Integrated Pest Management) recommendations for insect control. They publish information that works but unfortunately many of the so-called “organic” methods have not been tested adequately. 

 http://ipm.ucanr.edu/PMG/r605300311.html

            Pyrethrin sprays come from “organic” sources and some sources are manufactured. Read the label. The label makes this distinction.

            There are “synthetic pyrethrins”, some called pyrethroids, labeled for controlling this insect pest on pistachios. They do work if the directions on the label are followed. Synthetic pyrethrins are designed by chemists to “mimic” natural pyrethrin’s toxicity. But they are synthetic and may or may not be as “safe” to use as pyrethrins.

            I usually do not promote recommendations found on the Internet that have not been shown to have a history of success. If I do mention something without a history of control, I follow it up by mentioning so.

Honeybee Education for Students

I got this email and I thought it was interesting. I searched "beepods" and didn't find any negative reviews. I am not endorsing but it sounds interesting.

I'm looking for people who know teachers, principals or parents in the USA who might be interested in getting a honey bee hive at their school or non-profit organization centered around programming for kids.

I have access to a few grants for 2018 that would allow for school's in the USA to start a sustainable beekeeping project on their campus. Time is critical though, so it's important to start the process right away because the funding opportunities are coming to a close soon in 2017.

http://schoolgrant.beepods.com/honey-beehive-grant-schools-usa

Contact

brian@beepods.com

Learn How to Start Roses from Cuttings Sept 28

University of Nevada Cooperative Extension and the South Valley Rose Society are collaborating and offering educational meetings throughout the fall. On Thursday, Sept. 28 at 7 p.m. at our Lifelong Learning Center located at 8050 Paradise Road, Las Vegas, Nev. (I-215 and Windmill Lane). Find out how to start roses from cuttings at this free, open to the public, workshop.

Bring your favorite cutting (miniature or mini-flora).  Bring your cuttings wrapped in a wet paper towel.  Cuttings need to have about 6 - 8 eyes (buds) and pencil diameter.

Hume has a been a member of the American Rose Society (ARS) since 1982 and a proud holder of a Life Subscription To ARS. Hume was the President of South Valley Rose Society. She also served as President of Las Vegas Valley Rose Society twice and first Vice President for 8 years. Hume has successfully started roses from cuttings for over 10 years.  Her percentage of success in cuttings survival rate is over 90 percent.  Hume likes everything roses: rose people, rose exhibiting, rose books and rose clothes.

All educational meetings are held at 7 p.m. at the Lifelong Learning Center located at 8050 Paradise Road, Las Vegas, Nev. (I-215 and Windmill Lane). For more information, please call the Master Gardener Help Desk at 702-257-5555 or email lvmastergardeners@unce.unr.edu.

Successful Lemon Tree Growing in Las Vegas

This comment was sent to me about growing lemon successfully in the Mojave Desert. From the looks of the fruit I think it is a Lisbon lemon, one of the true lemons unlike Meyer which is not a true lemon and much more hardy to winter cold than Lisbon. This tree is located in the NW part of the Las Vegas Valley, north of Grand Teton.

We planted our lemon tree in Fall of 2006 as a 24" box. It has grown to a height of 20 feet plus and has produced a major crop every year but one. In that year we had a major freeze and we removed over a hundred pounds of frozen fruit, we have had a full crop every year since.

Our tree is positioned in an alcove that faces south.

We wrap the tree every winter on the south face of the tree and leave a vent at the top so the heat build up from the wrap during the day can vent.

We hand fertilize on four sides of the tree in most years and have general fertilizer tank that we fill twice a year in the spring and fall.  

Pine Needles Added to Soils. Good or Bad?

Q. I've added some new shrubs under pine trees and they are all doing poorly. I've read that pine needles are acidic and can change the pH balance in the soil. I've also read that's not true. Could the pine needles be affecting the new shrubs?

A. I am on the side of "it doesn't make much difference". Yes, pine needles contain a lot of resin and they don't break down quickly. But having them on the surface of the soil, or mixed into the soil at about 5% of the soil volume, makes no difference at all!

Using pine needles like these from a Chir pine problem in desert soils when used as a surface mulch. If they are mixed into the soil, try to keep the amount less than 10% by volume. They decompose much faster when they are shredded. They help lower soil pH which is very important in desert soils.

            Besides the resin, there is some slight lowering of pH (more acidic) which in our soils is actually helpful. Hopefully you amended the soil under pine trees with compost at the time of planting.

            Digging a hole large enough for plants under pine trees can be difficult because of the roots of the pine. Don’t be afraid to cut pine roots when planting. Allow these cut roots to heal 24 to 48 hours before they are buried in the soil again.

            Look closely at the amount of light these plants are receiving. Some plants grow nicely with 50% or more sunlight available to them. Others need much more than this for good growth. As an example, Bermudagrass can handle about 10% shade while tall fescue can handle nearly 50% shade.

            Generally speaking, flowering plants need lots of light compared to non-flowering plants. Signs of a lack in light can be a general failure of the plants to thrive, leaf drop and a general thinning of the canopy, and leaf yellowing. You may have to remove some of the lower limbs to allow enough sunlight to the plants growing beneath the canopy.

            This link about pine needle mulch is from Clemson University in South Carolina where most soils are acidic. Our soils are nearly 100 times less acidic (more alkaline) than those in many parts of South Carolina!  
http://www.clemson.edu/extension/hgic/plants/other/compost_mulch/hgic1604.html

            The pH scale is logarithmic, not linear. A pH of 5.5, a common pH value for acid soils, is 100 times more acidic than our soils with a pH of 7.5. Our soils commonly range from 7.8 – 8.5.

            Pine needles decompose more quickly if they are cut or shredded.

Lawns Keep Weeds out from Its Density

Q. I have lots of weeds in my lawn and the more I pull it out, it seems the more comes up! Besides spraying with Roundup, what can I do?

 

A. The density of a lawn prevents weed problems. Weeds invade your lawn because the lawn is not thick enough to "choke out" existing weeds and prevent weeds from getting established.

            A lack of density can be from too much shade, mowing the lawn too short, disease or insect problems, not applying fertilizer often enough or a lack of water.

            Mow at least once a week. Mow tall fescue at a 2 inch height above the soil. Never mow or "weed whack" tall fescue below 1 1/2 inches in height. This opens the lawn up for weed invasion.

Line trimmers used 2 edge lawns like this one managed by a landscape company cuts fescue too short which encourages invasion by Bermuda grass.

            Bermudagrass lawns need full sunlight. Tall fescue lawns should receive no less than 75% of full sunlight. Some people will say 50% but I think that’s right on the edge. If it's less than 75% sunlight, remove or decrease the amount of shade by pruning trees causing this shade.

            How do you know the percentage of shade? Look at the ground under the canopy at noon. The amount of shade is easier to estimate during this time of day. If it’s 100% shade, open up the canopy with a few pruning cuts that remove entire limbs from the trunk.

By looking at the ground beneath the tree you can estimate the percent shade.The percent shade under the canopy of this tree, not out the open, is maybe 25%, not enough for fescue to grow well.

            Lightly fertilize lawns every 4 – 8 weeks when using quick release mineral fertilizers. In most bags of inexpensive fertilizer, half of the rate listed on the bag is enough to apply if you are using a mulching mower.

            Apply quick release fertilizers to fescue lawns 4 times during the year during the major holidays of Valentine’s Day, Memorial Day, Labor Day and Thanksgiving. Bermudagrass lawns are fertilized during the heat of the summer but ending by September 1 if overseeding.

            Slow release fertilizers are applied in larger amounts but less often. They are expensive but they save labor. Make sure a fertilizer application is applied at Thanksgiving if you want to maintain a green fescue lawn through the winter.

Osmocote is a well known slow release fertilizer

            Make sure lawns are irrigated overhead with “head to head coverage” from sprinklers. This means that water from sprinklers are thrown far enough to hit the neighboring sprinkler.

            Make sure water pressure to sprinklers is not above or below the range recommended for the nozzles of your sprinklers. Inappropriate water pressures cause poor coverage of the lawn.

            Avoid disease problems by irrigating during the early morning hours just before sunrise.

When Should I Prune Meyer Lemon?

Q. When is the proper time to prune Meyer lemon? We have a large crop of lemons ripening now. The tree is very dense and the fruit is on the outside perimeter of the tree. Last time I pruned it in January or February and had no fruit that year. Can I do it now in September or wait until October or November?

A. Meyer lemon, not a true lemon, is usually harvested in December or possibly as late as early January. But do not harvest it later than this. Harvesting time is your signal for pruning. Waiting longer than this can possibly remove fruit during that growing season.

Meyer lemon grown in protected culture in Afghanistan.

            Prune immediately after harvest. Do not delay harvesting the fruit or this can confuse the tree about when to flower again and may affect the quality of the fruit.

            It is strange your Meyer lemons are ripening now. Fruit can take nearly 11 months to mature. Harvest the fruit when sugar in the fruit reaches a minimum of 10 Brix. Brix is measured with a refractometer. It’s handier to taste the fruit and see if it’s ready. When it is sweet, harvest it.

Refractometer

            Citrus is not pruned much, only to remove crossed or broken branches. You could remove a few limbs too close together which would allow more light inside the tree canopy. Probably removing 3 or 4 limbs would be enough.

Citrus response to pruning cuts

            Make sure the pruning saw or loppers has been sanitized and sharpened before pruning. Do not leave any stubs unless you want regrowth from them.