plant health care

Arbor-wellness: Fusarium Wilt

Fusarium wilt is a common wilt fungal disease that spreads mostly through the soil.  The fungi enter through the roots and interfere with the water uptake of the palm.  It is considered mostly fatal to them and doesn’t show symptoms right away so infected trees can often spread the disease.

Typically considered fatal, there is some promising research that shows some potential treatments that greatly prolong the life of the palm. Proactive treatment is recommended on otherwise non diseased palms.

My lower leaves are dying very quickly on some of my big feather palm trees. What could be wrong?

If these are Canary Island date palms, it is most likely fusarium wilt. This is a destructive fungal disease that is becoming more widespread. You should notice on newly infected fronds that one half of the frond dies first. As the disease progresses, the younger leaves will also be affected and the plant will eventually die.

Can I save these palms?

If the disease has spread throughout much of the palm canopy, then it should be removed and disposed of properly. Proper disposal is important to minimize the risk of spreading.

What about my other Canary Island date palms that appear ok now?

They should be treated on a regular basis to prevent establishment of the disease in them. Since it spreads by water and air, nearby Canary Island date palms will be infected eventually. This disease can survive for years in the soil, and is spread by water, insects, and garden equipment.  The fungus develops during hot weather; dry weather and low soil moisture encourage this plant disease. 

Will it spread to other types of palms?

No just the Canary Island date palm is susceptible, typically.

Click the button above this article to get in contact with an Arborwell arborist!

california, fusarium wilt, palm tree, plant health care

adelgids on hemlock

Arbor-wellness: Keep Adelgids away from your Hemlocks

What are these cottony looking white things on my Hemlock? 

Most likely they are adelgids. Adelgids are similar to aphids and can be very devastating in large numbers. They prefer Hemlock trees but are also found on other conifers like Douglas fir, larch, pine and spruce. They can produce white, cottony tufts on bark, branches, twigs, or needles. 

Will they harm my trees?

When present in large numbers, adelgids may cause yellowing and early dropping of needles and dieback of terminals. They can retard or kill trees, although healthy plants can usually tolerate small adelgid populations.

Can I get rid of them?

When the population builds high enough, there are ways to treat your conifers to reduce the populations. Treatment now is important if the populations are causing problems. Otherwise preventative treatments in the fall or early spring will help.

What can I do to help my tree look better?

Proper nutritional feeding and avoiding tree stresses – like lack of water or even salt build-up, will help. On conifers it is important not to over feed them and produce excess growth. At Arborwell, we use a very specific program that has the proper balance of nutrients for each type of tree. If you suspect salt may be a problem, we can identify how bad the problem is and provide cost effective solutions for that.

Fill out the form below to contact your Arborwell Arborist today and we will be happy to check out your hemlock – and all your conifers – to keep them healthy, now and for the future.

adelgids, arborist, conifers, hemlock, insects, plant health, plant health care

commercial tree services

Arbor-wellness: Keeping Palm Trees Healthy

Most pictures of California include palms in the skyline. They have become an iconic symbol of the state. There is even one California based fast food company that feature palms in their logo and at all of their sites. The taller palms are easy to see in the skyline and remind us of sunny days and warm breezes.

For the most part palms seem to be easy to grow. They grow quickly, are fairly drought tolerant and handle most of our weather variances well. However, they do need maintenance and – in many cases, protection – from certain diseases and insects.

While we classify palms as a type of tree, they are very different from shade trees or evergreen conifers. They are actually closer related to grasses and as such, have very different needs than most other trees.

With palms it is important to make sure they are planted correctly. They need well drained soil, to be planted at the right depth and with enough space for their roots. Palm roots don’t extent too far though so smaller planters are acceptable for them. However, they will still need some water so the planter needs to allow for them to be watered when needed.

They also need regular fertilizer. Most of our soils in a city environment do not contain the components necessary for a palm to truly thrive. Palms receive a bulk of their nutrients from a very small area, so that area needs to be replenished on a regular basis. For most palms, feeding twice a year with a natural fertilizer blended especially for palms should be adequate. For larger palms like the Canary Island date palm, three times a year is recommended.

Watering is critical, but it also depends on the soil type and the drainage. IF your soil is sandy and drains well, watering every four to six weeks is usually adequate for an established palm. If the soil is heavy or doesn’t drain well, water less often. You should also consider improving drainage and the soil conditions if the soil is compacted and tight.

Protection from diseases. Several of the prevalent diseases on palms – like pink rot and diamond scale – are worse when palms are stressed or not growing vigorously. Proper water, drainage and fertilization that we discussed above will reduce the incidence of these problematic diseases. However, protective treatments should be made until the underlying soil, drainage or watering problems are fixed.

The remaining concern is insects on palms. While generally there are not a lot of pests that can bother palms, on occasion they will become infested. Aphids, scale, mealy bugs and mites are the most common insects we see. These don’t kill a palm, but they can weaken it and allow diseases or other problems to proliferate. If these have been a problem on your palms, proper treatments will reduce the problems and allow your palms to thrive again. In the San Diego area, there is a destructive newer insect that does kill palms. It is called the South American palm weevil. One of the largest insects we deal with, it attacks the upper growing tip of the palm and completely destroys it. Since this is the only growing part of the palm itself, the palm does not survive. Proactive treatments are the only possible solution.

If you are worried about the health of your palm trees, or you would like some advice on a maintenance plan for them, reach out to your certified arborist at Arborwell. We will be happy to visits your site and inspect them and develop a wellness program for their long term health and survival.

arborist, palm tree, plant health care, tree care

common tree diseases

Arbor-wellness: Bacterial Leaf Scorch

I’ve been told my oak trees have bacterial leaf scorch, what is that?

Bacterial Leaf Scorch is a devastating disease of shade trees caused by a bacteria. The bacteria themselves live inside the tree’s water conducting tissue. They “cluster” inside the water transport tissue and essentially block water transport, which leads to the scorch symptoms.

The disease will slowly progress throughout the tree for up to a decade causing dieback and eventually killing the tree.

What trees are affected by it?

Symptoms and damage are usually most visible on pin and red oaks, but shingle, bur and white oak can be affected as well. It can infect elm, sycamore, mulberry, sweetgum, sugar maple, and red maple.

How does it spread?

Insects like sharpshooters, treehoppers, leafhoppers, and spittlebugs spread the bacterium from one tree to another. These insects feed on the xylem tissue and will inoculate the tree if they carry the bacteria with them.

Can you treat for this?

It is best to treat before the tree has Bacterial Leaf Scorch or in the early stages of it. Your Arborwell Arborist can develop treatment plans after determining the scope of the problem on your site. They can determine if preventative treatments or early curative treatments are required. If certain pests are prevalent, treatment to prevent their establishment may be recommended.

Also remember that a stressed tree will develop symptoms faster, so keeping trees properly watered and mulched are another way to help reduce the spread of this disease.

If you are concerned about bacterial leaf scorch, or other problems on your trees, contact your Arborwell arborist to help you create the most effective management plan for them.

arborist, bacterial leaf scorch, plant health care, tree care

Arbor-wellness: Leaf Spot

I see dark spots on my maple leaves and many of them are falling off. Is this a problem?

Your maple probably has a type of leaf spot disease. Leaf spot is a term used to describe a wide variety of diseases affecting the leaves of ornamental and shade trees. The majority of leaf spots are caused by fungi, but some are caused by bacteria. Leaf spots on trees are very common. They often result in some leaf drop. When the leaf drop is severe, your trees can be at risk of suffering damage until they recover.

How does it spread?

Most spread by rain or water splashing on their leaves. They often overwinter on fallen leaves, so leave removal in the fall we reduce many of these diseases. There are many different leaf diseases and some require fairly specific treatment, so having a professional help identify a management plan is critical.

How do they affect tree health?

If you think of a tree as an energy factory, the amount of leaves and the time they stay on the tree greatly influence the amount of energy they produce and store throughout the year. (Think photosynthesis.) when a tree loses the majority of its leaves from a leaf spot disease, the tree cannot store enough energy over time and becomes more susceptible to other diseases or insects.

Can you treat this disease?

Yes, in cases where significant damage is expected, treating either before or during the infection is appropriate. Preseason protection is always the best, but options exist for treating early before the disease becomes widespread too. Typically, some nutritional feeding is recommended to help the tree recover from the stress of these leaf diseases.

What else can I do?

Some slight changes in how you care for your trees can help reduce the incidence of leaf diseases. Proper pruning to keep the canopy open is the first step.  Avoiding overhead watering on the foliage is another important step. Keeping your trees healthy is also important. Be sure to fertilize correctly, though. At Arborwell, we use a nutritional feeding program that is proper for your trees and your soil conditions.

If you are concerned about leaf spot or other problems on your trees, contact your Arborwell arborist to help you create the most effective management plan for them.

disease, leaf spot, plant health care, spring

Arbor-wellness: Tussock Moth

What is a tussock moth and why are they so damaging?

There are many types of tussock moths that all have distinctive clumps of bristles on their backs of the caterpillar larvae. The adults are usually a smaller dull brown or white moth. The damage is done by the caterpillar – which are voracious eaters of foliage with the capability of defoliating entire groups of trees. On the west coast the most important species are the Western Tussock moth, the Douglas-fir Tussock moth and the Pine Tussock moth.

Why are they so numerous?

Most caterpillar species like the tussock moth go through population swings, building up a population level for several years, then seemingly disappearing for several years before returning in large numbers again. The presence of predators of these pests plays a large role in those population swings. For the Tussock moth, the overwintering cocoon in the trunks of trees can help indicate the potential of a population outbreak.

Are there safe methods of keeping their population low?

At Arborwell, we strive to find the safest, most effective solutions to pest problems. For the Tussock moth and other caterpillars, we use a commercial version of a biological suppression product that is effective on caterpillars. This fits most LEED and organic type programs. Timing is very important to be effective so often we recommend two or more treatments in a given year. Preventative treatments are available that work inside the tree – eliminating the need to spray the canopy of the tree.

If you are concerned about Tussock moth or other caterpillar problems in your trees, contact your Arborwell arborist to help you create the most effective management plan for caterpillar damage on your trees.

arborist, plant health care, spring, tussock moth

Arbor-wellness: Fire Blight

This time of year, it is often easy to spot an ornamental pear in the landscape because it will often have burned tips with brown leaves at the tip of branches. This is a classic symptom of a bacterial disease called fireblight. This difficult to control disease starts in the spring by small infections at the tip of a branch and moves further down the branch during the spring, killing as it goes. The result is the blackened tips that usually have a bend or crook in them, similar to a “shepherd crook”.  Ornamental Pears are the most common tree in the landscape in our region that get fireblight, but apples, firethorn, crabapples and several other species are also susceptible.  Click here to find out about fireblight control and how Arborwell can help prevent this on your trees.

My trees seem to be dying at the tips, what is this?

If the tips are crooked, the color is dark brown to black and the tree is in the apple family, it is probably a bacterial disease called fireblight.

How do I suppress it?

Fire blight is a bacterial disease so it behaves somewhat differently that most fungal diseases and control of it can be a little more complicated. Fall or winter preventative treatments are the most cost-effective way to suppress fireblight on susceptible trees. If your trees are already infected, we treat with an antibiotic injection as well as the preventative treatment. These two treatments together seem to be very effective.

What kinds of trees get fireblight?

Trees and shrubs in the apple family are susceptible to fireblight. This includes Apples, pears, crabapple, hawthorn, loquat, mountain ash and toyon and shrubs like firethorn and rose. Because it will spread by wind and rain from one type of plant to another, treating all the susceptible plants on your site is usually a wise idea.

How do I get rid of the dead tips, there seems to be a lot of them?

Proper pruning is really critical when you have fireblight. Pruning needs to remove all of the infected stem, so knowing how far down to make the cut is very important. Disinfecting the tools used to prune with is also important because bacterial spores from an infected tree can transport fireblight to other trees very readily. Timing of when to prune is also important. When a tree is pruned during the time fireblight is active, new infections can more easily occur.  At Arborwell, we know how to make a good management plan for your ornamental pears and other susceptible trees that maintains their health and safety for years to come. Contact your Arborwell certified arborist for professional management of fireblight and all your tree needs.

Fire Blight, plant health care, trees

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