Spider mites can be a problem during hot, dry weather

I will be giving a series of four classes about establishing a desert orchard starting the first Saturday in November and continuing through Nov. 24. The class will be held 1-3 p.m. at Ahern Rentals Academy, 1722 W. Bonanza Road.

The focus will be on high and medium density fruit production for residential landscapes including how to grow multiple fruit trees in a single hole. Class size is limited. Registration can be found online at Eventbrite.

Q: I have a fruit tree with leaves that are brown on the edges and covered in dust. Some of the leaves are turning gray-green on branches, and the tree does not look healthy.

A: Most likely the tree damage was caused by spider mites. Spider mites are a summer pest problem during hot, dry weather.

Another telltale sign that you mentioned is the dusty appearance of the leaves. This dust results from dead spider mites left behind as the population grows.

Look for feeding damage to the leaves caused by spider mites. This feeding damage causes tiny yellow dots scattered all over the surface of the leaf and accompanied by tiny black dots the size of this period.

By the way, the tiny black dots are mite poop. Even though mites feed on leaf bottoms, the yellow dots can be seen on the top of leaves.

A common misconception is that webbing must be present if mites are the problem. Spider mites leave behind webbing, like the weak form of a spider’s web. But not all mites that cause plant damage spin webs.

So, finding webs when there is damage is not a dead giveaway that the damage is from mites. It could be one indicator, though. There are spiders that are beneficial to plants.

Mite attacks to plants may come after the application of a hard pesticide. Bad mites are always present on plants, but their numbers are controlled by predatory insects and even “good mites.” So, applying a hard pesticide to control borers, for instance, could lead to an outbreak of spider mites because the predators were killed.

What can you do? Confirm that spider mites are the problem. Use a white paper test. Shake or slap an infested branch on a white piece of paper or paper plate. Closely look at the white surface for tiny dots, the size of a period, crawling along the paper.

Smear them with your fingers if you aren’t sure. If you see lots of them, along with plant damage that I described, you have confirmed mite damage.

Multiple applications of soap and water sprays do a good job controlling small outbreaks. Hosing the leaves of plants monthly, or after a dust storm, removes dust from the leaf surface which can increase spider mite populations.

Severe infestations of spider mites may require a pesticide application. If spider mites were a problem during the year, be sure to apply two dormant oil sprays during the winter months.

Q: I have two Mexican fan palms in my backyard that are 16 to 18 feet tall. One is 3 feet from a retaining wall and 6 feet from a pool. Another is 3 feet from the corner of my house, which is on a slab. Do I need to worry about the roots damaging the wall, pool or slab?

A: The short answer is you should be concerned anytime something that can get large is growing close to anything that can be damaged. The good news is that palm roots don’t typically damage walls, swimming pools or concrete slabs as much as other types of tree roots. But they can cause damage.

Palms, in general, are not a good choice around pools, but Mexican fan palms get huge and should never be planted close to structures. Smaller palms, such as windmill and Mediterranean fan palm, would be a better choice. The closest large fan palms should be planted to walls, swimming pools and house slabs is perhaps 10 feet away.

There are a couple of options if you don’t want to remove these palms. One is installing a root barrier so that palm roots are deflected away from structures that could be damaged. Root barriers are installed and extend about 30 inches deep or more and reside slightly above soil level.

The second option is to use water for directing root growth. In deserts, soils are normally dry due to a lack of rain. Tree roots grow where water is available. By placing irrigation water away from walls, cool decking or a house foundation, root growth can be directed away from these problem areas.

Water does not need to be applied evenly under plant canopies. I recommend keeping water 2 to 3 feet away from these potential problem areas.

Q: My Italian cypress trees started to lose their color and then die. Upon inspection of the trunk, I saw borers in them. Borers seemed to take place within two months or so and killed a few mature trees. I treated them with Bayer Tree and Shrub Insect Control but wanted to know if there is anything else I can do to help save them.

A: Damage from borers or boring insects is typically a slower progression than a couple of months unless the plants are small. You are right; the progression in many plants is a change in color from a vibrant green to a dull, gray-green color as the limb and leaves are dying from a lack of water.

My guess is borer damage to your trees started before this year. Internal damage to the trunk from borers can be present for several years before enough damage has accumulated to result in the death of older trees. If trees are growing vigorously, they can recover from light borer damage on an annual basis.

This color change due to damage starts in midsummer when air temperatures begin to heat up and plants require more water. Damage from boring insects begins in midspring (March) but gets progressively more intense as these insects become larger and more voracious feeders. By midsummer (June and later) internal damage to limbs and the trunk can be extensive, unrecoverable by the plant, and the supply of water from the roots is cut off.,You chose the correct insecticide to use, but it was probably applied too late. The best time to control boring insects with these types of insecticides is in midspring when they first become active.

Consider using pesticides as a last resort because they can contribute to other pest problems. Death of boring insects can happen in a few days when systemic insecticides are applied as a liquid drench to the soil.

Q: I have a greengage plum tree that is 18 years old and produces plenty of plums each year. In August I saw sap coming out of one branch and along the trunk in several places. Last week the bark started to separate, and it looks like the trunk is starting to split. The leaves on that limb are starting to die. This side of the tree receives the west sun. All the other branches on the tree appear to be fine.

A: Greengage is a good plum for our desert climate and 18 is not old for a plum tree. Plums can be sappy compared to other fruit trees but from your description, it sure sounds like borers. I would take a very sharp knife that has been sanitized and start actively looking for borers.

It is possible to remove the outer layer of bark covering the trunk and limbs and reveal the immature form of this insect, called the larva, causing the damage. Once exposed like this, it will die. Expose all the damage caused by borers down to the healthy wood. Leave this exposed area open for healing. I would say that about 80 percent of the time this is an effective way to remove the borer and allow the limb to recover.

Bob Morris is a horticulture expert and professor emeritus of the University of Nevada, Las Vegas. Visit his blog at xtremehorticulture.blogspot.com. Send questions to Extremehort@aol.com.

ad-high_impact_4
Local
NFR Day 6 Highlights
Highlights from the 6th go-round of the 2018 National Finals Rodeo in Las Vegas on Tuesday, Dec. 11, 2018. (CBS Sports Network/PRCA)
Las Vegas Bowl Teams Talk Shop at Maverick Helicopters
Arizona State, Fresno State talk to the media at Maverick Helicopters.
NFR- Will Lowe
NFR Bareback Rider Will Lowe talks with Aaron Drawhorn about his 15 years at the NFR, starting to ride at age 7, and renewing his wedding vowels this year in Las Vegas before night 6 of the National Finals Rodeo.
Veterans Village
Veterans Village and Veterans Village II were created to assist homeless veterans get back on their feet. (Mat Luschek/Las Vegas Review-Journal)
Holiday party cocktails
Veterans Village II Unveils Model Container Home
Veteran's Village II unveiled a model container home. The organization will be building 10 of these container homes to house veterans of the village. Mat Luschek/Las Vegas Review-Journal
NFR Day 5 Highlights
NFR Day 5 Highlights
NFR- Kory Koontz
NFR Team Roper Kory Koontz talks about his years at the event since 1992, his dynamic with a 23 year old partner Dustin Egusquiza, and how he contines to perform with diabetes with Aaron Drawhorn outside of Thomas & Mack before round 5 of the National Rodeo Finals.
Meet the woman behind the Las Vegas Bowl
Melissa Meacham-Grossman is the associate executive director for the Las Vegas Bowl. (Jason Bracelin/Las Vegas Review-Journal)
NFR Highlights Day 4
NFR highlights day 4
NFR Introduces Golden Circle Of Champions
For the first time, the National Finals Rodeo has partnered with the Santa Maria Elks Rodeo to offer the Golden Circle of Champions. The event brings in 20 children and their families from around the country that have previously or are currently fighting life-threatening cancer.
NFR Time Lapse 2018
Watch Thomas & Mack Center transform from a basketball court to an arena fit for the National Finals Rodeo in Las Vegas. Video courtesy of Las Vegas Events.
RJ's Mark Anderson on the UNLV loss
Review-Journal sports reporter Mark Anderson recaps UNLV's loss at Illinois. Video by Mark Anderson/Las Vegas Review-Journal
Joel Ntambwe on performance against Illinois
UNLV forward Joel Ntambwe talks about the 18 points he scored against Illinois. Video by Mark Anderson/Las Vegas Review-Journal
Amauri Hardy on loss at Illinois
UNLV guard Amauri Hardy talks about Saturday's loss at Illinois. Video by Mark Anderson/Las Vegas Review-Journal
Marvin Menzies on loss at Illinois
UNLV basketball coach Marvin Menzies talks about Saturday's loss at Illinois. Video by Mark Anderson/Las Vegas Review-Journal
Baby Roman's mother and his doctor talk about his medical condition
Baby Roman's mother and his doctor talk about his medical condition. Roman was born Dec. 13, 2017 and has been at Sunrise Children Hospital with a rare heart condition since. Bizuayehu Tesfaye/Las Vegas Review-Journal @bizutesfaye
NFR 2018: Unique Gifts At Cowboy Christmas
Before you head over to the Thomas and Mack for NFR, be sure to check out some of the unique and one of a kind items at Cowboy Christmas!
NFR: Dale Brisby
Day two of the National Finals Rodeo has started and Premier Vegas Sports host Cassies Soto interviews social media influencer Super Puncher Dale Brisby.
103-year-old celebrates birthday at gym
Joe Rosa of Las Vegas celebrated his 103rd birthday celebration at 24 Hour Fitness in Summerlin Friday, Dec. 7, 2018. After being the victim of a hit-and-run crash, Rosa's medical team told him he would never walk again. Rosa credits physical therapy and a personal trainer at the club for his return to health. (K.M. Cannon/Las Vegas Review-Journal)
Henderson native Mason Clements finished second in NFR bareback go-round
Mason Clements discusses his second-place bareback ride on opening night of the National Finals Rodeo in Las Vegas, Nevada, on Dec 6, 2018. (Ron Kantowski/Las Vegas Review-Journal)
Marvin Menzies on where UNLV stands at this point
UNLV basketball coach Marvin Menzies talks about where UNLV stands at this point in the season. (Mark Anderson/Las Vegas Review-Journal)
Public memorial service for Jerry Herbst
The Mob Museum
Saddle bronc rider Joey Sonnier earns spot at NFR after overcoming years of drug addiction
Joey Sonnier started saddle bronc riding at 18, but at 20 he began using methamphetamine to cope with the work of the rodeos and became addicted. At 39, after years of addiction and a low point that pushed him to rehab, he's qualified for the National Finals Rodeo. (Rachel Aston/Las Vegas Review-Journal)
Core Arena opens at the Plaza downtown in time for NFR
Core Arena, downtown's first permanent outdoor equestrian center, opens to the public at the Plaza. The arena will be used for events throughout the year, including the 10-day 2018 Wrangler National Finals Rodeo at the Thomas
MountainView Hospital celebrates the opening of the new Sunrise Health GME Simulation Center.
MountainView Hospital celebrates the opening of the new Sunrise Health GME Simulation Center. (Bizuayehu Tesfaye/Las Vegas Review-Journal) @bizutesfaye
NFR Preps Livestock for the Limelight
NFR’s Jed Pugsley discusses the care that goes into preparing the rodeo’s livestock for Las Vegas’ big event.
Grand Menorah lighting begins Hanukkah
Rabbi Shea Harlig led the ceremonial lighting of the menorah to begin Hanukkah at the Fremont Street Experience. There were also performances by the Desert Torah Academy's choir and the Dancing Dreidels. (Rachel Aston/Las Vegas Review-Journal)
Perla Gumm has spent the past few years collecting toys for kids for the LV Rescue Mission
Perla Gumm has spent the past few years collecting toys for kids for the LV Rescue Mission. It's something she started even before the rescue mission was her beneficiary; she just felt a need to collect toys and teamed up with them later. Bizuayehu Tesfaye/Las Vegas Review-Journal @bizutesfaye
Tony Sanchez wraps up the UNLV season
UNLV football coach Tony Sanchez wraps up the season. Video by Mark Anderson/Las Vegas Review-Journal
Life
An elegant Tea Party for substance abuse and homeless women
An elegant Tea Party for substance abuse and homeless women at WestCare Women Children Campus in Las Vegas. Bizuayehu Tesfaye/Las Vegas Review-Journal @bizutesfaye
Former 51s manager Wally Backman chats about new job
Former Las Vegas 51s manager Wally Backman talks about his new job with the independent league Long Island Ducks during the Baseball Winter Meetings in Las Vegas, Nevada, on Dec. 10, 2018. (Ron Kantowski/Las Vegas Review-Journal)
Inside the kitchen at Springs Preserve
The staff of Divine Events do party preparation in the kitchen at Divine Cafe at Springs Preserve. With nine parties the following day, this is a particularly busy time for the crew. (Heidi Knapp Rinella/Las Vegas Review-Journal)
Pearl Harbor survivor Edward Hall talks about his memories of Dec. 7, 1941
U.S. Army Corps Edward Hall, a 95-year-old survivor of Pearl Harbor talks about his memories of that horrific day. Bizuayehu Tesfaye/Las Vegas Review-Journal @bizutesfaye
Roy Choi on cooking for Park MGM employees
As he prepares to open his new restaurant Best Friend later this month at Park MGM, celebrity chef Roy Choi took the time to cook for the resort’s employees Tuesday. (Al Mancini/Las Vegas Review-Journal)
Best Friend Menu Reveal Wednesday
Chef Roy Choi tells us what to expect from Wednesday’s Facebook Live Menu Reveal for his new Park MGM restaurant Best Friend. (Al Mancini/Las Vegas Review-Journal)
Las Vegas Great Santa Run
People participated in the 14th annual Las Vegas Great Santa Run which raises cubs for Opportunity Village.
World Holidays Exhibit At The Natural History Museum
Migratory Bird Day teaches adults and kids to celebrate birds
Different organizations offered activities for kids and adults to learn about birds and celebrate their migration journey at Sunset Park. (Rachel Aston/Las Vegas Review-Journal)
"Jackson: The Red Rock Canyon Burro" is a children's book about Red Rock Canyon
"Jackson: The Red Rock Canyon Burro" is a children's book about Red Rock Canyon (Janna Karel Las Vegas Review-Journal)
Interfaith Amigos speak in Las Vegas
Celebrity photographer dedicates dance book to Las Vegas shooting victims
Behind the scenes with local celebrity photographer Jerry Metellus as he talks about his Dance For Vegas coffee book dedicated to the 58 victims of the October 1 shooting. (Marcus Villagran/Las Vegas Review-Journal) @marcusvillagran
Dreamsickle Kids Foundation founder Gina Glass talks awareness
Gina Glass, 35, founded Dreamsickle Kids Foundation to raise awareness for sickle cell disease in Nevada. (Jessie Bekker/Las Vegas Review-Journal)
TOP NEWS
News Headlines
Add Event
Home Front Page Footer Listing
Circular
You May Like

You May Like