How to treat moss on trees

How To Naturally Remove Moss From Trees

Finding moss growth on trees is highly common in Washington and Oregon because of our rainy, wet climate. A common question that homeowners ask us is whether moss on trees is dangerous to tree health.

While the short answer is no, the extra weight moss lays upon on older trees can weaken their stability in windy storms and hide potential tree diseases from view.  The good news is that most moss plants are epiphyte. This means they are not parasitic and they derive their nutrition from the air, not the tree, so while the weight could be dangerous, the moss itself isn’t harmful. Here’s our quick rundown on moss, and how to prevent and remove moss from your trees.

What causes green moss on trees?

Collectively known as lichens, algae and moss, this green growth arises because the environmental conditions allowed for it. Moss thrives in damp, dark areas, so regions covered by shadows or consistent cloud cover are more susceptible to moss growth. In addition, moss tends to prefer to grow on older trees with less vitality than younger trees.

While green moss on trees isn’t necessarily harmful, it can contribute to a myriad of potential problems. Thick moss growth on trees is heavy and can throw trees off balance. This may make for dangerous conditions during windy storms and other inclement weather. In addition, because moss grows more thickly on older trees, this can make it difficult to notice potential health problems like disease and tree death.

Removing Moss from Trees

Although moss isn’t usually harmful, if it overtakes your trees it can smother new buds and become a nuisance if you have a lot of growth. Not only will it cover your trees, but it can overtake your lawn and even grow on your house (which is actually harmful). Fortunately, it can be very easy to remove from your trees before it becomes problematic.

If you are not a fan of the moss on your trees, a natural way to get rid of it is to remove it with your hands. Because it isn’t rooted in trees it should be easy to pick off, especially if its growth is thick. Wearing gloves, try peeling or picking it off with your hands from the tree bark. For any left over moss, you can use a soft bristled brush to scrub it off the trees.

Another natural way to remove moss is to use a pressure washer to separate it from the tree bark. When you use this method, be sure and stand back from the tree about five feet and wear protective eyewear. Once the moss is separated from the tree, you should be able to pick it off with your hands.

Preventing Moss Growth

Because moss loves dark, damp areas, to keep it under control or prevent its growth, you need to try to eliminate the moisture and shade around the tree. Try to refrain from watering your trees when you water the lawn, and water your lawn deeply rather than frequently.

Avoid standing water in the yard: You can aerate your lawn to remove large puddles of water around the base of the tree. This will discourage moss growth by cutting off its supply of readily available water.

Pruning your trees to focus more direct sunlight to the trunk and major branches can help keep moss growth under control. Your goal is to aim for those leafy branches that are covering the base of the tree in shadow. To invite sunlight into your trees, trim the branches to open up the crown and reduce shading. If necessary, try to remove any landscaping that is causing too much shade around your trees.

Pacific Northwest Tree Experts

Thinking your trees might be suffering from more than just moss? Read about common tree diseases, and contact your local arborist for help. Call (503) 504-4179 or (503) 679-1410.

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How to Get Rid of Moss on Trees [6 Simple Steps for Killing Moss]

Remove moss from tree trunks and branches by performing the following steps:

  • Spray with a non-toxic moss killer.
  • Let moss killer work for 1-2 days.
  • Remove dead moss with a soft broom or brush.
  • Use a hose or gentle pressure washer to remove moss residue from the tree.
  • Prune tree branches to allow more sunlight to reach previously mossy areas.
  • Fertilize trees to strengthen them to resist moss.

Some tree care companies use copper sulfate or lime-based products for moss removal, but these are toxic chemicals that can damage nearby painted structures, including your home. By following the process detailed below, you’ll be able to remove tree moss without damaging your house, trees, or lawn.

Table of Contents

Should Moss be Removed From Trees?

While not always the case, moss can cause harm to the trees in your yard. For instance, branches covered with green moss or hanging Spanish moss are much more likely to break during storms and rainfall. Additionally, moss collects moisture. This can attract fungi, mold, and insects like chiggers. A thick growth of moss can even stop air and sunlight from reaching new buds and leaves.

  • Moss on tree branches can make them heavier and prone to breakage.
  • Moss traps moisture close to the tree, inviting pests, disease, and fungi.
  • Moss can hide signs of plant disease and smother new buds.

Although moss doesn’t send roots into trees or steal nutrients from them (moss gathers what it needs from the air), it can still be damaging. Most experts recommend removing moss from fruit trees, as excess moss can pose harm to nearly any tree species.

What Causes Moss to Grow on Trees?

Moss is most often drawn to tree trunks and branches that are frequently wet and do not get much sunlight. Trees planted in boggy or shaded parts of the yard can be overtaken by moss. Also, if your tree is losing foliage, a moss problem can be an indication that you no longer have a healthy tree.

  • Damp areas of the tree that receive little sunlight.
  • Moss on a tree can be a sign of disease.
  • Older trees are more prone to moss growth.

Moss also tends to latch onto older trees. This can increase the chance of broken branches. In dry conditions, moss may not weigh much, but it can double or triple in weight during rainy periods. This additional weight, plus the high winds of stormy weather, can spell disaster for older trees.

6 Steps to Kill Moss on Trees

The steps outlined below will help you get rid of moss on your trees.

Spray Moss with a Safe Removal Product

Rather than a chemical product that isn’t safe for application near your home, use a safe moss-killing spray, like BioAdvanced Moss & Algae Killer. It’s safe for use on lawns, homes, and trees, so you don’t have to worry about harmful overspray.

  • Choose a home-safe moss killer.
  • The spray bottle is designed to attach to the end of your garden hose for easy use.
  • Spray moss on tree trunk and branches, making sure to evenly apply it to all moss present.

The spray bottle for this moss killer attaches to the end of a garden hose. Turn on the water and thoroughly spray the moss on your trees. Killing moss with a spray like this makes the following removal steps much easier. Living unwanted moss may stubbornly cling to trees.

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Allow Spray to Soak into Moss

Once you’ve applied the moss killer, it will go to work immediately. You may see results in as little as 3-5 hours. However, for complete moss-killing results, 1-2 rain-free days may be required.

  • Light moss may be killed in 3-5 hours.
  • Heavy moss growth may require 1-2 days for moss killer spray to fully work.
  • If it rains within 1 day of application, a second application may be necessary.

If it rains within a day of moss killer application, it may reduce the spray’s effectiveness. If this happens, apply moss killer a second time.

Use Broom or Scrub Brush to Remove Dead Moss

Getting rid of brown, dead moss is much easier than living moss, but it won’t just come off on its own. It needs a little encouragement. To remove moss:

  • Wait until moss turns brown due to moss killer spray.
  • Use a soft-bristle broom or scrub brush to remove dead moss from the trunk and branches.
  • Scrub carefully, making sure not to damage tree bark or buds.

Avoid using a stiff broom or brush for this step, as it may damage the tree during the removal process. In order to protect new growth from harm, moss removal is often performed during the fall or winter months, while the tree is dormant.

Use Water to Remove Remaining Moss

A hose-end sprayer, pressure washer, or power washer should be used to remove stubborn moss or moss growth in hard-to-reach places. If you are using a pressure washer, begin with a gentle setting and wide spray, then gradually increase strength, making sure the tree bark is not damaged during moss removal.

  • Use a hose-end sprayer or pressure washer to remove the remaining moss.
  • Practice caution when using a pressure washer, to prevent damage to tree bark and branches.

This step should effectively remove even the most stubborn moss and lichen hiding in the nooks of your tree. If the tree is young or has thin bark, avoid using a pressure washer for moss control as this may damage the tree.

Prune Tree Branches to Prevent Moss

Because moss loves shady areas, a great way to follow up moss removal is by pruning to prevent moss from coming back. Cut back limbs to increase sunlight on the tree trunk and branches. Remove dead or damaged limbs where moss is likely to grow.

  • Trim branches to increase sun exposure on the tree trunk.
  • Remove dead or sick limbs. These are prime areas for moss growth.
  • Consider removing lower limbs that receive poor sunlight.

If your tree is prone to heavy moss growth, especially with hanging moss species like Spanish moss, consider removing shaded lower limbs or any tree branch where moss will multiply quickly.

Fertilize Trees to Increase Moss Resistance

Moss loves to grow on weak or sickly trees. The stronger the tree, the less likely it is to be overtaken by moss. One of the best methods to prevent moss growth is to fertilize the trees in your yard.

  • Moss is more prone to grow on weak trees.
  • Try these Winchester Gardens Tree Fertilizer Spikes to strengthen your trees.

Tree fertilizer spikes provide a slow release of essential nutrients to the soil that will help boost the vitality of your old or struggling tree. It’s a simple way to combat moss growth as part of your lawn care routine.

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How To Get Rid of Moss on Trees and Shrubs

Moss is easiest to remove if it has been killed first with a safe moss spray. Allow the spray to work until it turns moss brown (as little as 3 hours or as long as 2 days). Then, scrub the dead moss off the tree with a soft brush or broom. To remove stubborn moss, try spraying with a hose or gentle pressure washer.

Once you’ve removed the existing moss from your trees, prevent it from coming back by pruning tree branches to allow more sunlight to reach shaded areas of the trunk and branches. Then, fertilize your tree with fertilizer spikes. These easy steps are safe for anyone to perform, remove moss growth on trees, and keep your trees happy and healthy for years to come.

How to get rid of moss and lichens on fruit trees

Garden trees covered with moss and lichen slow down growth, bear fruit poorly, over time their branches dry up and die. In addition, the growths on the shoots create a favorable environment for the habitat of insect pests. How to protect trees?

Tree cleaning procedures should be carried out in early spring, when the buds have not yet swelled on the trees (usually in March), and in late autumn, when the last fruits are harvested (in November). At the same time, before autumn processing, it is imperative to collect and burn fallen leaves.

If fruit trees are treated with drugs when buds have already blossomed on them, this will lead to the death of the entire plant.

This is what trees covered with lichen (left) and moss (right) look like

How and with what to treat trees from moss and lichen

tree branches. After a week, lichens and mosses should fall off on their own. Also, do not forget to cultivate the land under the trees, because iron sulfate is an excellent means of preventing various diseases of fruit trees.

If scales of lichens and mosses still remain on the surface of the trees, remove them mechanically. Spread pieces of film or rags under the plants and scrape the surface of the trunk and branches with a wooden spatula, brush or old burlap.

When cleaning fruit trees, do not use metal scrapers: they can injure the bark.

Thinning pruning saves the garden

If your garden is heavily neglected, almost all trees are covered with lichen and moss, then before starting the cleaning procedure, it is necessary to carry out a sanitary felling. Since some trees can be so heavily affected by lichen growth that it will be useless to clean them.

Examine each tree carefully and cut off overgrown branches. Also, don't forget to keep pruning your garden trees regularly to keep their crowns from thickening. This will favorably affect the additional flow of air and light. In such a garden there will be no high humidity and, accordingly, excessive growth of mosses and lichens.

After mechanical thinning (scraping), remove large parts of lichens and mosses. Then prepare a solution of iron or (alternatively) copper sulphate: dissolve 300 g of the powder in 10 liters of water.

First mix vitriol powder thoroughly in a small amount of hot water, and then, adding cold water little by little, bring it to the required volume. Treatment with a solution in this concentration is carried out once every 5 years. And sometimes once is enough - and your garden will forever get rid of mosses and lichens.

Easy method of cleaning trees from moss and lichen

If your garden trees are not heavily covered with growths, then you can use an easier cleaning method: mix 1 kg of salt, 2 kg of wood ash, rub 2 bars of laundry soap into this mixture, pour 10 l hot water, bring to a boil, cool and coat the tree trunks with the resulting composition.

If lichens appear periodically in your garden, then use the antifungal preparation Skor: it is diluted in accordance with the instructions and applied to trees in early spring.

After cleaning, it is necessary to whitewash the tree trunks. The solution can be prepared independently (dilute 1.5-2 kg of slaked lime in 10 liters of water) or use ready-made mixtures (for example, garden acrylic whitewash).

Note: Acrylic whitewash is not recommended for young trees.

Whitewash is carried out in dry weather (autumn or early spring) at an air temperature of at least 2°C. All wounds and cuts on trees should first be covered with garden pitch.

Avoid running trees and inspect their bark annually. If you find small "islands" of moss, immediately carefully clean them off, because large growths are much more difficult to deal with.

Moss on trees - benefits, harms, methods of prevention and control. Photo — Botanichka

Everyone remembers well from school lessons that moss grows on trees from the north side, and this is a reliable reference point for determining the cardinal points in the forest if you suddenly get lost. True, this is not entirely true. Moss on a tree can grow on any side, it just grows more from the north, since there is more moisture and less sun. But it's in the forest. But what if moss grows on trees in our garden? Here we will not get lost, and we do not really need landmarks. Is there any benefit from such a neighborhood, or does it only harm our pets? Let's try to figure it out.

Moss on trees - benefits, harm, methods of prevention and control

Useful properties of moss on trees

Moss was one of the very first plants on Earth. Its age is almost three hundred million years. There are a huge number of varieties of moss. There are so many of them, and they are so diverse that in botany there is a whole section devoted to the study of mosses - bryology.

Moss can grow anywhere, in any climate zone. With temporary adverse changes in the environment, the moss takes on a state of suspended animation. When conditions change for the better for him, his life processes are restored.

Some experts believe that moss and lichen growing on trees indicate clean air in the environment. Japanese scientists, for example, conducted an experiment and determined that moss is not only a natural bio-indicator that reacts to air pollution and the amount of moisture in it. Since moss uses water and nutrients from the environment where it grows for its growth, it is also a wonderful air purifier from various pollutants. Depending on changes in the ecosystem, it changes its appearance and intensity of growth, and under especially unfavorable conditions, it can die completely.

A thick layer of moss has the ability to accumulate and retain radioactive particles.

There is an opinion that trees covered with moss or lichen do not suffer from frost and sunburn.

At the same time, the appearance of moss on the bark of a tree may indicate a disease of the latter, and it is worth paying attention to. On an old or diseased tree, bark growth slows down or stops altogether, and such a surface is even more suitable for the growth of moss and lichen.

These plants are not considered parasitic, they feed on moisture retained in the bark. In the absence of moisture, mosses dry up, but when it appears, they begin to grow again. They do not harm trees, as they grow only on the surface of the bark, without penetrating deep into the trunk.

Can moss interfere with the development of trees?

And now consider the potential harm from the appearance of such a guest in our garden. Mosses are tiny perennial plants up to 50mm long. They do not have flowers, and instead of roots - root hairs (rhizoids). Rhizoids are one elongated cell or several cells growing in a row. They serve to attach the plant to the base surface and absorb moisture.

A sporophyte grows directly on the body of the moss - a thin stalk, at the end of which a box - sporangium is formed, inside this box a large number of spores mature.

Mosses reproduce by spores, therefore, having appeared on one tree, they quickly move to neighboring trees by wind, rain, insects, which, first of all, violates the aesthetic beauty of the garden and makes it look unkempt.

Moss spreads over the bark of a tree in a solid dense carpet, which prevents free access of air and moisture to the surface of the trunk and branches. This slows down the development of the tree and reduces its fruitfulness.

In addition, moss is an excellent hiding place for various pests, larvae, bacteria and spores of already parasitic plants. Therefore, it is better to still prevent the appearance of moss on your trees.

A sporophyte grows directly on the body of the moss - a thin stalk, at the end of which a box is formed - a sporangium, where spores ripen. © Martin LaBar

Preventing moss from growing on trees

Preventing moss from becoming the master of your garden requires proper planting of trees and bushes. Mosses love shady places, old trees. Therefore, try to keep your trees growing in open, well-ventilated areas.

Also, to prevent the appearance of moss, it is necessary: ​​

  1. Timely remove old branches and extra plants, make thinning pruning of the tree crown. This is done so that the crown is blown by the wind and dries well after the rain, so that more sunlight gets on the branches.

2. Ensure that the soil does not become acidic. The optimal acidity of the soil for the garden should be in the range of 5.5-6.5 units, this is an indicator of slightly acidic soil.

It is possible to approximately determine the acidity of the soil, and it is divided into acidic, neutral and alkaline, at home, without resorting to chemical analysis. To do this, put a small amount of earth from the garden on a glass surface and pour table 9 percent vinegar. If after that a lot of foam appears, then the soil is alkaline, a small amount of foam indicates that the soil is neutral, the absence of foam indicates acidic soil.

It is good to deacidify the soil with wood ash. The weight component of ash is from 700 g to 1.5 kg per square meter. Average application rate 500-600 g.

Read more about soil acidity and methods of its deoxidation in the material Soil acidity - how to determine and deoxidize.

3. For the winter, whitewash the trunks with a solution of lime (3 kg of lime per 10 liters of water), to which copper sulfate (100 grams), clay or mullein can be added. The trunk and lower skeletal branches of old trees are whitened in dry and warm weather.

4. It is possible to prepare a solution for coating trees from simple ingredients: 1 kg of salt, 2 kg of wood ash, two pieces of grated laundry soap, pour 10 liters of hot water and bring to a boil. Cool and can be used by brushing the solution on the affected areas.

Moss on a tree is an excellent hiding place for various pests, larvae, bacteria and spores of parasitic plants. © Peakpx

Moss control measures

If preventive measures are not enough, and you notice the appearance and spread of moss in your garden, you will have to deal with it.

The safest and at the same time effective method is to spray the plants with a solution of ferrous sulfate. You should take 30-50 grams of powder per 1 liter of water. Processing of trees is carried out in early spring, always before the buds swell, or late in the fall after the leaves have fallen.

We spray not only the trunks and skeletal branches with the solution, but also the ground around the tree to disinfect it. Moss dies and falls off (do not forget to lay a film under the tree). Iron sulfate is also an excellent protector against fruit rot, scab, it will help fight powdery mildew and other tree diseases.

Be aware that the strong concentration of ferrous sulfate solution we use to rid trees of mosses and various fungal diseases can cause burns on young shoots and leaves. The bark is not sensitive to such a saturated solution.

It is not toxic to humans, but certain precautions must be taken to protect the eyes and respiratory system during spraying operations.

The advantage of ferrous sulfate is that it is a contact fungicide, that is, it works only on the surface, does not absorb into cell sap, does not enter the plant, does not spread through stem cells, unlike systemic preparations.

The remaining areas of moss can be cleaned with a wooden stick or scraper so as not to damage the bark, you can even use a hard mitten. It all depends on how much moss is left on your tree. Pre-lay a film or thick fabric under the tree so that moss spores do not get into the ground. After cleaning, everything that turned out on the film must be burned. Mechanical cleaning is carried out in wet weather in late autumn or early spring after the end or before the start of sap flow in the tree.

It is very good after cleaning to treat the wood once with a solution of copper sulfate (400 g per 10 liters of warm water). The processing time is also carried out in early spring or late autumn during the absence of sap flow in the plant.

Pay attention to the safety precautions when working with blue vitriol. This substance is poisonous, you need to work with gloves, avoiding contact with the skin. A solution of copper sulfate should be used within 4-5 hours after preparation, then it becomes unusable.

Another spray option is oxalic acid diluted with water at a ratio of one part acid to eight parts water.

When the areas covered with moss are small, or moss appears on your trees only from time to time, you can use the fungicide "Skor". It is used as a prophylactic agent with a long duration of exposure, and for the treatment of certain diseases.

Warning: "Skor" should not be used repeatedly, such procedures may lead to insusceptibility of microorganisms and contribute to the ineffectiveness of this drug. For example, this may apply to powdery mildew.

Use caution when using this drug. If the period of spore formation in moss growths has already begun, then this drug is useless.

Before any treatment of wood, it is necessary to cut dried branches, remove frozen bark, clean all damage to the bark, places of cutting and breaking of branches and cover with garden pitch.

Dear readers! If you want to have a healthy garden and high productivity of fruit trees, check the condition of their bark at least once or twice a year.

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