COVID-19 UPDATE: Arborwell is Open and Performing Essential Tree Care Services at this time

Arborwell is Open for Essential Tree Services

COVID-19 UPDATE: Arborwell is Open and Performing Essential Tree Care Services at this time

Arborwell is Open for Essential Tree Services

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Arbor-Blog

Pests + Diseases

Threats to your Redwoods

Specific Redwood Issues

Phytophthora Root Rot

Phytophthora root rot is caused by a soil-borne organism. When first infected, the coast redwood’s foliage may wilt, yellow and dry out but remain on the tree. The leaf damage is because of the slow death of the redwood’s roots, which limit its ability to absorb adequate amounts of water. Eventually, the entire tree will turn brown and is unlikely to recover. If caught early enough, phytophthora root rot’s presence in the soil may be managed, or at least reduced, with the application of a fungicide containing potassium phosphate. But this is not always successful.

Armillaria Root Rot

Armillaria root rot rarely infects healthy coast redwoods. But stressed, under- or overwatered redwoods may fall prey to this disease. This soil-borne disease enters the plant through the roots, where it may be years before symptoms become noticeable. An infected coast redwood may slowly decline over a period of years, section by section. Or it may suddenly wilt and then die in a few weeks. To identify armillaria root rot, pull back the tree’s bark. Infected trees will have white or yellow fan-shaped mycelium growing between the bark and the wood. There is no cure for armillaria root rot. Infected trees should be uprooted and destroyed and the soil sterilized before another tree is planted in its place.

  • Phytophthora root rot is caused by a soil-borne organism.
  • When first infected, the coast redwood’s foliage may wilt, yellow and dry out but remain on the tree.
care for redwood trees

Botryosphaeria Canker

This fungus feeds on the cambium, sapwood and inner bark of weakened trees, forming large cankers. As these cankers grow, the fungus develops pimply black fruiting structures. The cankers will eventually girdle the branch, cutting of the nutrient supply to the leaves. To get rid of botryosphaeria canker, prune away the infected plant tissue.

Watering Issues

This is an important consideration as more and more sites are being watered with reclaimed water. The drawback to this water is the high salt content of most reclaimed water. At Arborwell, we can recommend ways to reduce the salt build-up from reclaimed water. This is important because too much salt will cause problems with many trees. If your site has reclaimed water, the advanced moisture sensors we use also measure salinity. This helps us watch and act to reduce the salt build up before it affects the trees.

Pests

Spider Mites – There are many species of spider mites, but their control is similar. The most important distinction between types is determining if you have warm season mites or cool season mites. This determines the timing of some of the treatments. There are a variety of ways to control mites, including ways to reduce populations naturally.  

Bark Beetles – Bark beetles in particular, lay their eggs inside the bark of trees. When the larvae hatch, they begin to feed on the living tissue just inside the bark layer. This slows or stops the transportation of water and nutrients up and down the tree. As they mature, they pupate into adults, exit the tree and look for more trees to attack. When enough bark beetle larvae are feeding on a particular tree, the tree can’t recover and dies. Sometimes the beetle will introduce a disease into the tree which either helps kill the tree, or increases the rate of wood decay, making it dangerous faster.

Tip Miners – While most massive redwoods scoff at the presence of pests, some pose more problems than others. Watch for signs like yellowed or browning leaves, which could indicate the presence of cypress tip miners.

Click the button at the top of the page to schedule an inspection today. Our ISA Certified Arborists can come up with a proactive plan to protect your Redwoods.

commercial tree service

Why is Soil pH Important?

One measurement we use in helping to determine overall soil health is soil pH. This is a common concept and important to understand, but is only one of many measurements we use to determine overall soil health. A good soil health recommendation will take many factors into consideration, but soil pH is the starting point, as it helps us determine nutrient availability, the tightness of soils, and the ability of soil biology to thrive or not. The wrong pH may encourage fungal pathogens, while the proper soil pH range will encourage good soil microbes.
The pH scale runs from 0 to 14. Any pH reading below 7 is acidic and any pH above 7 is alkaline. A pH of 7 indicates a neutral soil. Most trees will grow in soils having a pH between 6.5 (slightly acid) and 7.2 (slightly alkaline). Ideally, maintaining a soil close to 6.8 is perfect for most trees. There are a few plants that prefer a soil pH below 6.0. These “acid-loving” plants include azaleas, rhododendrons, and blueberries. The soil pH for these plants can be lowered by incorporating elemental sulfur (S) into the soil. Since the soil acidifying response to elemental sulfur is slow, it should be applied and incorporated a year before planting.

When soil pH is too high, many nutrients start to become unavailable to the tree. They may exist in the soil in adequate amounts, but are tied up and not available. One example of this is with pin oak a maple trees. When the pH is too high, they will show signs of iron or manganese deficiency, which is characterized by yellowish green foliage. Most of the time, iron and manganese are found in good supply in the soil, but are not soluble and thus not available. When this occurs, it is important to treat both the short-term problem of yellow foliage and the long-term problem of soil pH.

Soil microbes are also somewhat dependent on proper pH too. When the pH is too low or too high, certain pathogen fungi or bacteria will tend to proliferate. When the pH is in the proper range, the good guy microbes tend to thrive. These guys battle the pathogens and help prevent disease infections from the soil borne pathogens. Other factors besides pH determine how healthy the good soil microbes are, so those factors must be taken into consideration, too.

Soil “tightness” is a third factor that is affected by soil pH, at least indirectly. When the soil pH is too low, there is often a lack of calcium in the soil. When supplied in the adequate ratio compared to other minerals, the soil micro-pores will be more open, thus allowing more water and air space at the root level.
When a soil problem, such as pH, is suspected to be contributing to the problems with a tree or trees, a comprehensive soil test is always recommended. If you are concerned about this problem, ask your Arborwell Arborist for an evaluation and recommendations.

ph balance, plant health care, soil

sudden oak death

What Causes Sudden Oak Death?

What causes Sudden Oak Death in trees and plant life? Sudden Oak Death, or SOD, is caused by the pathogenic fungus Phytophthora ramorum. This waterborne mold pathogen infiltrates plants and trees through contaminated irrigation water, wind-blown rain, infected plants, and contaminated pots and soil mixes. This fungus is also associated with other tree wellness issues like Ramorum leaf blight, Ramorum dieback, and Phytophthora canker.

disease, fungus, oak tree, tree health

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palm tree maintenance

Bay Area Pests: The Palm Weevil

Are your palm trees safe from invasive Bay Area pests? The palm weevil, which crossed the US-Mexico border several years ago, is continuing to spread north. A study by the University of California recently uncovered that the palm weevil flies much faster and spreads more rapidly than previously anticipated, and how easily area trees could fall prey to this palm tree pest.

Palm Weevils Pose a Substantial Threat to Trees in the Bay Area

Palm weevils attack many palm species throughout the region, including fruit-bearing date palms, coconut palms, sago palms, African oil palms, and Washingtonia fan palms. If the palm weevil impacts date palms in Imperial and Coachella, their damage could cost millions. If you fear a palm weevil infestation, contact an Arborwell tree wellness expert immediately. Palm weevils can kill a Canary Island palm tree in just 49 days. Hundreds of palms in Tijuana and San Diego have already succumbed to the pest. Worsening matters, the palm weevil also carries a roundworm on its body that is a known vector for red ring disease, which is lethal to date palms.

Black Palm Weevils May Be Harder to Eliminate Than Red Palm Weevils

Unlike their relative, the red palm weevil, brought to the US from Southeast Asia for food, the jet-black South American palm weevil may prove harder to eradicate. The pest is spreading naturally from neighboring Mexico, stretching its wings as far east as Texas and as far north as Bonita, CA. Once infested, a single palm tree could host up to 1,000 weevils. Females of the species are remarkable flyers, capable of covering 61-87 miles in a single day, increasing the likelihood of infestation and widespread destruction.

Timely Pest Control is Crucial to Managing Palm Weevil Infestation

With their prolific procreation and capacity for flight, it is essential that we all work together to prevent and control the spread of the palm weevil. Early identification of infested trees is crucial. If you see signs of crown damage or drooping/dead fronds, we recommend scheduling a complimentary assessment from an Arborwell certified arborist right away. We recommend removing infected trees from your Bay Area apartment community, HOA, commercial office, retail space, industrial park, or government facility immediately. This will not only stop the spread of the pests but prevent collapsing trees from injuring bystanders.

Identify and eliminate palm weevils fast with help from Arborwell Professional Tree Management. Contact us to schedule a complimentary tree assessment from a certified arborist for your San Jose, San Francisco, Walnut Creek, Seattle, Palo Alto, Menlo Park, Hayward, or Oakland commercial property today.

palm weevil, pest conrol, pests, Prevention

Fire Blight

Common Tree Diseases in California Cities

Do your usual tree management tactics seem to be falling short? The California climate, temperature extremes, and pollution can certainly do a number on landscaping, impacting tree health. However, the Arborwell team knows that disease may also be to blame. How can you distinguish environmental stress from illness? Check the trees on your California property regularly, watching for signs of these common tree diseases.

Anthracnose

Anthracnose is a fungus that affects a variety of plants and trees. It thrives in warm, moist conditions and multiplies very quickly during rainy spells, spreading through infected plant debris. Our plant health care experts identify it by the dark, sunken lesions it produces on affected flowers, fruits, leaves, and stems, which begin as small, irregular yellow-brown spots that darken and spread. Fortunately, with proper tree care from our knowledgeable arborists, anthracnose is not lethal.

Fire Blight

The Arborwell team frequently encounters this bacterial disease in the early spring. Though it doesn’t affect a wide variety of tree types, it is incredibly contagious and can cause significant damage very quickly. Fire blight attacks all parts of the tree, including blossoms, leaves, and branches, giving them a dark brown or black scorched appearance. It spreads through many vectors, including wind, rain, insects, and birds, and is frequently seen on California’s apple and pear trees. Left unchecked, it can kill a tree, necessitating removal and replacement.

Fusarium Wilt

Fusarium wilt is another widespread fungus we frequently see throughout the state. It is known for attacking food crops such as tomatoes and bananas and is one of many diseases affecting California palm trees. Fusarium oxysporum can live indefinitely in the soil without access to a living host and spreads easily, making it difficult to eradicate. The infection begins in the roots, interfering with water transport, causing lower (older) leaves to wilt and yellow. The disease then progresses to new growth until the plant eventually dies.

The Role of Pests and Disease

Experienced arborists know that weak and diseased plants are naturally more susceptible to pests. Infestations can quickly go from being an unsightly nuisance to a major problem, claiming the life of the trees on your commercial property. Watch out for these common offenders on sick or diseased trees:

  • Royal palm bugs
    These tiny, oval, yellowish bugs feed only on the freshly opened leaves of royal palms. Though they can make your palms weak and unattractive, if addressed quickly, we can save your trees.
  • Cabbage palm caterpillar
    Cabbage palm caterpillars feed on palm flowers, weakening the tree. Their reddish-brown larva also stains the tree, leaving behind an ugly mess. 
  • Palmetto weevils
    If young leaves on your palm trees are wilting and quickly dying, you may have palmetto weevils. If you don’t eradicate them fast, these black or red-winged pests can quickly kill your trees.
  • Gold spotted oak borers
    These tiny, invasive beetles kill oak trees and are fundamentally changing the landscape in the region.
  • Oak worms
    Oak worms feed on oak leaves, quickly consuming lush canopies to leave behind a scruffy, leafless tree. Caterpillars fall off trees en masse in May, littering patios, cars, and people.

Identify and manage common tree diseases in California cities with the help of Arborwell Professional Tree Management. Fill out our online form to schedule an arborist assessment for your ailing trees, or contact us at 888-969-8733 today.

Anthracnose, Fire Blight, fusarium wilt, tree health, tree management

palms.corporate1opt 470

Types of Palm Tree Pests in San Diego

There is no shortage of palm trees in San Diego. Sadly, there’s also no shortage of palm tree pests. In recent years, invasive, non-native insects have taken on a toll on these icons of the West Coast, making it challenging to keep your palm trees looking their best. Which types of palm tree pests do our San Diego arborists find causing the most damage to area landscapes?

Red Palm Weevil

red palm weevil

The Arborwell team frequently encounters red palm weevils when compiling arborist reports. One of the biggest threats to area palms, these giant 1.5-inch red-brown insects feed on over 40 different palm species. They have caused millions in economic losses globally.

A delicacy elsewhere in the world, these pests are believed to have been introduced when they were brought into the U.S. for food. However, red palm weevils can fly about a half a mile per day, and they quickly spread through the region by flight and through palm tree sales. Difficult to detect, no one identified the escapees until landscapers noticed area palms slowly dying, the trees looking brown and droopy.

Red palm weevils are tunneling insects with a long, slender snout, which the female uses to penetrate the bark of palms to deposit her eggs. Once hatched, the larvae burrow deep into the tree, consuming it from the inside out, and leaving behind a foul-smelling mush-like substance. Because damage begins high in the tree, where new frond growth emerges, the sound of the gnawing insects often goes unnoticed until tree wellness suffers.

Our arborists are familiar with the signs of red palm weevil infestation, which we often encounter during routine trimming. Our trained professionals know to watch for signs of red palm weevils, including larval tunnels and feces within leaf bases in the tree canopy. We can help you quickly quarantine and rid your grounds of these invasive pests using traps and trunk injection treatments.

Polyphagous Shot Hole Borer

arborist services palm tree

Unlike the massive red palm weevil, polyphagous shot hole borers are small; only the size of a sesame seed! Though tiny, these beetles have decimated hundreds of thousands of trees in Southern California, including healthy palm trees. Polyphagous beetles were discovered in the late winter of 2012, infecting several backyard avocado trees in Los Angeles, and have since spread to surrounding areas.

The pests were possibly introduced via shipments from Southeast Asia, though their specific origin remains unknown. The pest cannot fly but can hitchhikes in landscaping equipment, tree waste, and firewood. Another outbreak occurred a year later, found to be a second species of polyphagous beetle, the result of a second introduction rather than a spread of the L.A. infestation.

Polyphagous shot hole borers attack dozens of landscape tree species, tunneling within. They carry Fusarium, a fungus causing fusarium dieback, which affects hundreds of species. Unlike red palm weevils, these wood-boring beetles do not eat tree bark. They lay eggs in certain species that serve as reproductive hosts, such as California, Fountain, Jelly, and King palms, among many others. Like tiny farmers, they also use the tunnels they excavate to grow Fusarium, their primary food source, cultivating it within infested trees.

Our arborists can quickly recognize the signs of polyphagous beetle infestation and Fusarium dieback, dubbed the shot hole borer-fusarium dieback (SHB-FD) complex. Property owners typically notice limb dieback from the fungus, which blocks the transport of water and nutrients to leaves. When we see tiny little pinholes in tree bark, with sawdust-like powder around the holes, we scrape back bark to look for the tiny beetle in its circular galleries. As ongoing trials using natural predators progress, we use tree injection treatments to exterminate the polyphagous shot hole borer, devising a customized tree care plan to protect your landscape.  

Are pests taking a bite out of your landscape? Arborwell Professional Tree Management can help you control many types of palm tree pests in San Diego. Contact us at 888-969-8733 to speak to one of our ISA certified arborists, or to schedule an examination of potentially infested trees today.

palm tree pests, palm trees, palm weevil, tree health, weevil

leaves browning due to vert wilt

Arbor-wellness: Verticillium Wilt

We are seeing more trees this summer that look green and healthy one week and within a few weeks entire branches turn brown and leaves dry up, the most common cause of this problem is verticillium wilt. Verticillium is a soil borne root disease that usually infects through the root as they contact verticillium spores in the soil.

Many trees are susceptible to verticillium including, arborvitae, birch, crabapple, ginkgo, maple, oak, pine, spruce and tulip trees. What makes this disease so difficult is that by the time we typically see damage, the disease has spread too far and tree removal is usually the only option. Once a soil is infected it is very difficult to kill the spores, so it usually remains in the soil indefinitely. However, there are some ways to protect your trees and reduce the chance of infection.

My tree was looked good last week and now this week it has several branches with dead leaves, what’s wrong?

This is most likely verticillium wilt, which is caused by a soil fungus that can lie dormant in the soil for many years. When the roots of susceptible plants grow close to the spores, the fungus germinates and infects the roots of the plants through wounds or natural openings. The fungus spreads into the branches through the plant’s vascular system and at the same time, causes the plant cells to “plug” themselves. Once this happens, water can no longer reach the leaves and they wilt and die, often all along one or branches at a time. It often happens quite suddenly, although in some plants the leaves turn yellow or brown first.

Why is this so prevalent now?

That is a hard question to answer but yes, we are seeing more of this disease this summer and fall. Essentially, our trees are still recovering from the drought of several years back. Their root systems were compromised. The moisture this spring really encouraged new rooting and also encouraged more root diseases overall.

How can I be sure my tree has this disease?

On certain trees – maples and tulip trees in particular, elongated dead areas of bark, called cankers, may appear on diseased branches or trunks. On most trees with the disease, the sapwood of smaller branches is streaked brown or black, occasionally in other colors too. However, since not every tree exhibits this discoloration, testing tissue in a lab may be recommended to confirm the diagnosis.  

Will my tree survive?

Unfortunately, usually not.  There seem to be two forms of the disease, one in which plants die slowly over several years and another where they die rapidly within a few weeks. Trees that show minor branch wilt one year may show more the next year or may not show symptoms again for several years.

Is there anything I can do for the other trees on my property? 

There are ways to help protect your trees, particularly if they don’t show signs of the disease. First make sure the tree is not stressed – proper water and proper feeding are important here. Secondly, there are some good guy fungal species that do battle against this root disease and several others, too. The good guys inoculate onto the roots of a tree and fight and kill these fungal pathogens. (I like to use the analogy of probiotics that help our digestive system stay healthy.) But this process should start before verticillium wilt becomes established in the tree.

Our arborists at Arborwell can recommend a protective program for the trees that are susceptible on your site. Fill out the form below to get in contact with an arborist today!

preventative tree care, Prevention, root disease, tree care, verticillium wilt

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