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Can you use ashes in the garden


Using Wood Ash in the Home Garden – Wisconsin Horticulture

Authors: Kevin Schoessow, Extension Burnett, Sawyer and Washburn Counties
Last Revised: 02/27/2020
X-number: XHT1268

Home gardeners often ask if wood ash can be used as a fertilizer in vegetable gardens and flowerbeds, around landscape trees and shrubs, and on lawns.  Wood ash can be a valuable source of certain nutrients and can also be used to modify soil pH.  However, it needs to come from an appropriate source and its use should be based on recommendations from soil fertility testing provided by a professional lab such as the UW Soil and Forage Lab (https://uwlab.soils.wisc.edu/).

Using wood ash in home gardens can increase soil fertility and raise soil pH.

What are the potential benefits of using wood ash?  Wood ash contains nutrients that can be beneficial for plant growth.  Calcium is the plant nutrient most commonly found in wood ash and may comprise 20% or more of its content.  Potassium (also called potash) is another common component of wood ash, occurring at concentrations of up to 5%.  Magnesium, phosphorus and sulfur are also typically found in wood ash at concentrations of up to 2%.  Finally, wood ash can contain trace amounts of iron, aluminum, manganese, zinc, boron and other nutrients needed by plants.

In addition to its nutrient content, wood ash can help in neutralizing soil acidity.  When wood is burned, high amounts of carbonates are produced.  Carbonates react with and neutralize acid in the soil, causing the soil pH to increase.  The levels of carbonates present in wood ash (and thus its acid-neutralizing properties) will vary depending on the type of wood burned and how the wood was burned.  In general, wood ash has about 50% less acid-neutralizing capacity than commercially available acid neutralizers such as pelletized lime or aglime.  Approximately four cups of wood ash can be substituted for one pound of aglime.

What are potential downsides of using wood ash?  On occasion, even the best wood ash may contain heavy metals such as cadmium and lead, but the levels of these metals can be minimized by carefully selecting the wood that is burned to produce the ash (see below for details).   In addition, the increase in soil pH associated with using wood ash tends to decrease the likelihood of plants taking up heavy metals.  If wood ash is used at recommended rates, concentrations of heavy metals should be low enough not to pose a threat to plants, or to animals or humans who eat plants grown in treated areas.  If you are concerned about heavy metals in your wood ash, consider testing for these elements prior to use.  The UW Soil and Forage Lab (mentioned above) does not test for heavy metals at this time; however staff can help answer questions about heavy metal contaminants.

Because using wood ash tends to increase soil pH, applying it where acid-loving plants (e.g., blueberries, azaleas/rhododendrons, birch trees, red maples, pin oaks) are growing will likely not be beneficial.  Using wood ash may actually be detrimental and contribute to problems with chlorosis [see University of Wisconsin Gardens Facts XHT1002 (Chlorosis)].  In addition, many vegetables and other landscape plants prefer slightly acidic soils, so wood ash should be used judiciously when growing these plants.   Finally, in some cases, increased pH due to use of wood ash may promote certain diseases.  As an example, potatoes grown at higher pH tend to be more prone to potato scab [see University of Wisconsin Gardens Facts XHT1117 (Potato Scab)].

In order to use wood ash in the best manner possible, always make applications to garden soils based on the plants that are to be grown and based on recommendations from a certified soil testing lab.

What type of wood ash should I use?  If you decide that using wood ash is appropriate for your gardening needs, only use wood ash that has come from trees grown in natural areas.  DO NOT use wood ash produced from trees grown near industrial sites, in soils that may be contaminated with toxins or heavy metals, or if you have no knowledge of the origin of the wood that you are burning.  Also, DO NOT use ash produced by burning treated wood, waste oil, plastics or garbage.

How do I apply wood ash?  Prior to use, sift wood ash to remove large charcoal pieces, as well as any active embers.   Apply only the amount of wood ash recommended based on a soil fertility test and based on the nutrient needs of the plants that you intend to grow in the treated area.  Applying excessive amounts can lead to nutrient toxicity and/or nutrient deficiency issues in plants.  Applications of wood ash are generally limited to a maximum of 15 to 20 pounds (approximately a five gallon pail) per 1000 sq. ft., per year.  Spread wood ash evenly over the area to be treated (e.g., vegetable garden bed, established perennial flowerbed, lawn or other landscape area) during the winter.  Because wood ash particles are very fine and can easily be blown by the wind, avoid making applications when it is windy.  Whenever possible, apply wood ash to moist soil.  Where feasible (e.g., in a vegetable garden), work the ash into the soil using a rototiller, spade or rake in early spring.

Due to its alkalinity, wood ash can potentially pose a human health risk.  Therefore, when working with it, be sure to wear appropriate protective clothing (e. g., long pants, long sleeve shirt, gloves, eye goggles, dust mask) to limit exposures that might lead to skin, eye or respiratory irritation.

For more information on using wood ash in the home garden, as well as soil fertility testing:  Contact your county Extension agent.

20 Brilliant Ways to Use Wood Ash In The Garden

For many gardeners, wood ash is a plentiful and free resource. If you burn wood, you surely have plenty of wood ash that needs somewhere to go. Even if you don’t burn ash to heat your home, you may have a friend or neighbor who might be happy to let you clear away their ash and put it to good use in your yard or garden.

Wood ash is a free garden amendment that contains many nutrients and beneficial properties.Jump to:

Why Wood Ash?

What does wood ash do for your garden?

Wood ash is a useful fertilizer and amendment that can be used in the garden, on lawns, and in landscapes, too. It is a good source of several important minerals and nutrients for your yard and garden. It is also a highly effective amendment for modifying soil pH.

The most abundant mineral nutrient in wood ash is calcium. On average, the calcium content of wood ash is 20% or higher. Calcium is an important element that helps plants stave off diseases such as the notorious blossom end rot.

Wood ash is also a very good source of potassium—it is about 5% potassium. It is commonly known or referred to as “potash” for this reason, and potassium is the mineral that wood ash is most often used for. When people look for a source of potassium, they look to potash—wood ashes.

Other minerals found in wood ash are magnesium, sulfur, and phosphorous, all found at concentrations around 2%. In addition, wood ash contains trace amounts of manganese, iron, zinc, aluminum, boron, copper, and other trace minerals.

Besides being a source of potash, wood ash is also commonly used as an amendment to adjust soil pH. The high calcium content in wood ash is in the form of calcium carbonate. Calcium carbonate is what is in agricultural lime. One of the major uses of lime in gardening and landscaping is in raising soil pH to reduce its acidity and make it more neutral or alkaline (depending on the goal and how much is used). This makes wood ash an excellent, free resource for amending acidic soils or soils with a low pH.

It should be noted that the content and concentration of wood ash varies depending on the source, which is why we see an estimated range in contents and their numbers. If you would like to know more exact amounts of these nutrients in your wood ash you can have it tested.

How To Use Wood Ash in the Garden or Landscape:

Wood ash is very easy to use for the lawn and garden. The key lies in knowing when to use it, how much to apply, and what it is and isn’t good for.

When Should I Apply Wood Ash to my Garden?

Wood ash goes to work very quickly in the soil, so it can be applied shortly before planting, or even used as a top dressing.

Wood ash is a good annual soil amendment and fertilizer as long as it is not used on the “wrong” plants. The best time of year to apply wood ash to your garden or yard is over the course of the winter or in the early spring.

Look to wood ash when you need to add potassium (potash), sweeten acidic soil, and/or increase levels of calcium or phosphorous.

Fortunately, wood ash works relatively fast and so it can be applied almost up to planting time (and in some instances, as a top dressing or side dressing). For best results, it is recommended to apply it at least a month before planting.

When used as an amendment to adjust soil pH, wood ash only needs about a month to work. It works much more quickly than lime, so if you have missed your window and need a quick fix for soil pH, wood ash is a better choice.

As a rule of thumb, it is not recommended that you apply wood ash to soils that have a pH level of 6.5 to 7 or higher because it will make the soil too alkaline; however, that depends on how high a pH you are trying to achieve. If a more alkaline soil is the goal, wood ash will still be an option.

Ash can be used in place of lime for lawns as well. You will need to adjust the application rate to achieve the desired results (see the section on application rates below).

How Do I Apply Wood Ash to my Garden?

“Safety first” applies to using wood ash just as it would for any other type of fertilizer or amendment.

The first rule is to make sure that the ash you are spreading is well cooled and is no longer burning. Be aware that when ash is piled or bucketed when still hot the inner layers can hold heat and smolder for quite some time—days even. Avoid handling or spreading hot ash. Take care not to burn yourself and be especially careful if you live in a dry or fire-prone area.

Before you apply ash to your garden, sift out large chunks of unburned wood and coals.

If the ash you are using has large coals or chunks of unburned wood in it, sift the large pieces out before you spread it on your lawn or garden. This can be done by simply pouring the cool ash through a screen of one-quarter or one-half inch hardware cloth.

Wood ash is obviously quite light and can be irritating to the eyes, nose, respiratory tract, and to bare skin.

It is wise to wear safety glasses or goggles, long sleeves and long pants, gloves, and a mask or covering for the nose and mouth when you are applying wood ash. Avoid breathing in ash and do not spread ash on a windy day (not only is this less safe, but you may end up wasting this valuable amendment and fertilizer if it blows away).

Spread wood ash evenly and do not leave large clumps or piles which can result in too many salts concentrating in one area. Up to a half inch of ash is fine. Note that as an amendment to help improve soil tilth, heavy clay soils can take more ash than sandy soils can.

It is best to apply wood ash onto moist soil so that it stays where it is needed. If that is not possible, you may want to sprinkle or water the area after application. If spreading on loose soil, work the ash in as soon as possible to maximize its benefits.

How Much Wood Ash Should I Use in my Yard or Garden?

The application rate for wood ash will vary slightly depending on where you are using it and for what purpose.

Wood Ash Application Rate for Gardens and Flower Beds

A five-gallon bucket of ash is equal to about 20 pounds.

In the garden, the application rate for wood ash is between 15 and 20 pounds per 1,000 square feet. This is roughly equal to the amount of ash that you will get from burning one cord of wood.

A five-gallon bucket holds about 20 pounds of wood ash. So, to make it easy, use one five-gallon bucket of clean wood ash for every 1,000 square feet of ground.

If you are applying ash as a top-dressing fertilizer or amendment around individual bushes, spread one-half to one pound evenly around the base of the bush.

For individual plants, sprinkle no more than one-half inch thick around the root area at the base of the plant.

For larger trees and fruit trees, apply to the area of the base of the tree to a thickness of one inch deep.

Wood Ash Application Rate for Grass and Lawns

Wood ash should be applied at a slightly lower rate when used as an amendment for grass and lawns. It can replace lime for your lawn.

When applying to lawns, the wood ash application rate is a little lower. In that case, apply wood ash at a rate of 10 to 15 pounds per 1,000 square feet.

As mentioned previously, wood ash can be used in place of lime on gardens or lawns to increase the pH. If you have a good wood ash supply, you may want to switch that out and use ash in place of your annual liming. Note that wood ash has about half the concentration of calcium carbonate that lime has; so, as a replacement for lime, use twice as much wood ash as you would lime. Four cups (or one quart) is equal to about one pound of lime.

One of the benefits of using wood ash instead of lime is that it acts faster and affects a change more quickly than lime can. You should see results from wood ash within in a month. If you are soil testing, wait 30 days to test a second time to see if the desired results have been achieved. If not, you may apply wood ash a second time.

It is not advisable to use more than the recommended amount because overuse of wood ash can lead to pH problems in the soil.

Some Notes on Wood Ash Application

Learn how when, and where to apply wood ash and your garden will reward you.

Wood ash should be used judiciously. It is possible to overdo it with wood ash. A soil test—whether an at-home soil test or a test performed by a lab—is a good idea. Perform your test before applying wood ash so you know what nutrients your yard or garden may need and/or so you know if the soil pH needs to be raised. Calcium, phosphorous, pH, and other nutrients will be your main targets.

This is especially smart for vegetable plots because most vegetables want their soil to be a little on the acidic side (in the range of 6. 0 to 7.0). Depending on the natural acidity of your soil, you may need to reduce or suspend the amount of ash you apply so that you don’t change the pH too much (i.e., so that it is not made too alkaline for good plant performance).

Know the wants and needs of the plants you are growing. Not all plants have the same requirements, so you may need to use your wood ash selectively—apply the ash to some parts of the garden but not to others where the ash may pose a problem for the planned crop (see below for a list of plants to avoid using ash on).

More is not necessarily better if the amendment is not needed. Too much ash can cause “nutrient toxicity”. It might also cause the soil pH to be too high. Nutrient toxicity can result in plant deficiencies and imbalances. Imbalanced soil or soil with a pH level that is drastically off can make important minerals and nutrients inaccessible to plants, even if those minerals are abundant in the soil.

Overuse of ash and high soil pH can cause scab on potatoes, so, like lime, wood ash use should often be avoided where potatoes will be planted.

Chlorosis is another plant disease that can result from overuse of ash in the garden. It is characterized by a yellowing of the leaves which results from an interference with photosynthesis.

Plants That Benefit from Wood Ash Application

Ash is beneficial for many plants and bushes, but some are particularly partial to it. These include:

Plants to Avoid or Limit the Use of Wood Ash

Ash is not a good choice for plants that like acidic soils.

Ash is not recommended for use on all plants. These are usually the plants, trees, and shrubs that prefer more acidic soil and a lower pH. Avoid using wood ash on:

Using Other Fertilizers with Wood Ash

After applying wood ash you should test your soil before applying other fertilizers--you may not need them.

After applying wood ash, you should wait one month before applying other types of fertilizers. By this time the effects of the ash will be known. You may or may not need to apply other fertilizers once the ash has acted and it is quite likely that you will not need to apply all the fertilizers that you normally would.

When using wood ash as a fertilizer, nutrients such as phosphorous should be covered. If you do need to apply another fertilizer, nitrogen is what your soil is most likely to need.

Using Wood Ash in Compost

Extra wood ash is perfect for adding to your compost pile.

Wood ash is a great addition to the compost pile. If you are not using your ash directly on your lawn or garden, use any remaining ash in your compost heap.

Just like when it is applied to soil, wood ash helps to control the acidity levels in your compost pile, too, and helps to keep the resulting compost at a near neutral level; quality, neutral compost is more widely useful as it will not affect the acidity levels for different plants. Ash also (to a lesser degree) helps with texture and tilth and may help mitigate strong odors in your compost pile.

Spread wood ash evenly over the layers of material in your compost pile. A good rate is a layer of ash applied to every six-inch layer of material. Apply a light layer between one-quarter and one-half inch thick.

Sourcing Wood Ash for Gardens, Lawns, and Landscapes

One obvious source of good wood ash for your garden is your wood-burning home heating source (or a neighbor's!).

If you burn wood as a home heat source, you are in luck and have at least one source of wood ash for your garden. There are other places you can look for ash to use in gardening and landscaping, though. Here are some top sources:

Don’t think only of your own personal wood-burning sources—think of those of your neighbors as well. If friends or neighbors will not be using their ash waste themselves, they’ll probably be more than happy to let you take it off their hands. Ash from hardwood sources like maple, beech, and oak is more nutrient-dense than that of softwoods like pine and fir, but all are good sources and are useful in the garden.

Addressing Concerns Regarding Heavy Metal in Wood Ash

One way to minimize any potential risks of using wood ash in your garden is to know that the wood source from where it came is contamination-free.

There are instances where wood ash can sometimes contain heavy metals. According to the University of Wisconsin https://hort.extension.wisc.edu/articles/using-wood-ash-in-the-home-garden/ this is an occasional issue which can be further reduced by proper application and by informed selection of the types and sources of wood and ash being used for food production. Also, the rise in soil pH that results from applying wood ash means that plants do not uptake heavy metals from the soil very readily (whether those metals already existed in the soil or are the result of ash content). The risk to plants and their consumers (whether animal or human) is therefore low. To minimize the risk of heavy metals from ash use:

As long as your wood supply does not come from a contaminated area and the wood is not treated, it should be safe to use.

What constitutes a clean, natural wood source? It’s simple. Avoid wood and ash from:

Storing Ash for Later Use in the Garden or Landscape

If you are not using your ash right away it should be kept dry and out of the weather (for example, if you are storing ash to apply to the garden later and are not spreading it right away or using it immediately in the compost heap). Beneficial salts and nutrients will leach out of the ash with rain, melt, and water.

To preserve the integrity of your wood ash, it is best to store it in a metal container with a cover (making sure that it is cooled and no longer burning, of course!).

A galvanized metal garbage can works well.

Other Home and Garden Uses for Wood Ash

There are many handy, surprising ways to use wood ash in the home and garden!

If you have an excess of wood ash from your heating and burning, there are still more useful ways to use that wood ash, rather than waste it. Use extra wood ash to:

As you can see, ash is a lot more than waste. This heating byproduct is an excellent resource for the garden, and for the home, yard, and landscape, too.

Research and resources for additional reading:

https://extension.unh.edu/sites/default/files/migrated_unmanaged_files/Resource004042_Rep5718.pdf

https://pss.uvm.edu/ppp/articles/woodash.html

https://www.almanac.com/video/how-use-wood-ash-vegetable-garden#

https://site.extension.uga.edu/fannin-gilmer/2020/12/using-wood-ash-in-the-garden/

https://extension.umaine.edu/publications/2279e/#

https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/using-wood-ashes.htm

tips - Ukraine - tsn.ua

Many gardeners and gardeners use ashes as fertilizer. However, it must be remembered that this tool is not suitable for feeding all plants. TSN.ua talks about important points that you need to pay attention to if you want to bring ashes under trees, bushes or vegetables.

There are several rules for the use of ashes to feed plants and trees.

  1. Ash as fertilizer can only be used on acidic and slightly acidic soils . But on alkaline, it will only aggravate the situation. Be sure to find out what type of soil is on the site before use. To do this, purchase a litmus stick at any gardening store.
  2. Not all plants tolerate ash well, but only those that like acidic soils. Ash as a fertilizer is suitable for cucumbers, tomatoes, cabbage, peppers. But blueberries, mountain ash, viburnum, hydrangea, honeysuckle are best fed with potassium sulfate.
  3. Remember best time to apply ash . Experts recommend to do this in the spring of to additionally feed the soil. For this, such a mineral fertilizer is being prepared: ash 1 bucket per 3-4 square meters of land. After that, the soil becomes very loose.
  4. Do not scatter ashes on seeds that have begun to germinate . Ash is sprinkled under plants and bushes so that it comes into contact with the roots. Then they grow stronger and more magnificent.
  5. Well proven ash on aphids . To combat the pest, a decoction is prepared: sift 300 g of ash, pour water and boil for 20 minutes. Let stand, drain, add 10 liters of water and spray the affected plants.
  6. Use houseplant ash . For top dressing, you need to prepare such a solution: 50-75 g of ash per 5 liters of water, mix well. Steep for a week, stirring occasionally. This solution is suitable for feeding all indoor plants in the house. nine0014
  7. Such a mineral fertilizer as ash has proved to be excellent for rare feeding of plants in the garden and in the garden. To do this, take 1 glass of ash per bucket of water (10 liters). Pour only under the root of vegetables or bushes.
  8. Ash as fertilizer is excellent for strawberries and strawberries . You need to feed immediately after flowering. Apply 10-15 g of ash per bush. It will protect strawberries and strawberries from pests and gray rot.
    9. nine0011 When planting tree and shrub seedlings, a small amount of ash should be thrown into the soil so that the plant can quickly adapt to new conditions.

Wood ash contains quite a lot of potassium (10-12%), so it is very useful for cucumbers, tomatoes, strawberries, strawberries, potatoes, onions, peppers, cabbage, carrots, grapes, etc. Also in its composition you can find phosphorus and calcium, micro and macro elements that plants need for growth. Also, such fertilizer as ash is distinguished by the complete absence of nitrogen and any chlorine compounds. nine0005

See also:

Ashes as fertilizer - properties, rules and benefits of using

Mon, 21/11/2016 - 10:31 | Comments: 0 | Author: OLCHUKS

nine0070 Fertilizers that can be prepared from natural raw materials are of great benefit. Among them is ash, or ashes, obtained from the burning of wood material. Let's see what benefits the use of ashes brings as a top dressing for plants in the garden.

Even in ancient times, people noticed that after burning old, uprooted trees in these places, the yield is higher, the plants grow and develop better. They still get ashes now, burning prunings, branches of trees, bushes. You can add tops of garden plants, dried corn stalks, sunflowers. nine0005

Contents:

Useful properties of ashes, benefits of organic feeding

Usually the composition of the ashes cannot be the same, since different types of wood are sent to the fire. But the general formula for fertilizer was nevertheless deduced:

All these substances have a positive effect on the growth of garden plants, allows you to retain moisture in the leaves, stems, which is especially necessary during dry summers.

Enriching the soil with potassium, calcium, the fertilizer deoxidizes it, creating favorable conditions for worms that enrich the soil with nitrogen. nine0005

In addition to supplying vegetables and flowers with nutrients, ashes help against diseases of green spaces: cracking of carrots, blackening of tomatoes, rot of potatoes, black leg of rose bushes. You can use wood ash for indoor flowers. The use of ashes as plant food has been known for a long time and benefits both plants and the earth.

Fertilizer application methods

Ashes are used as organic fertilizer in three ways:

  1. Scattering dry ash around fruit trees, in cucumber holes, between rows of onions, you can provide the plants with the missing nutrients. This method of top dressing is carried out necessarily with mixing the ash with the soil. Usually, from one hundred to three hundred grams of ash is applied per square meter of the garden, which corresponds to half a liter. The procedure is carried out in the spring, when peat and sandy soil is enriched, and in the fall they are brought into loam. After the dry ashes have been scattered around the plants, the area is watered abundantly. Especially happy are the dry ashes of the beds with onions, as the ashes will save the vegetable from pests. nine0014
  2. A liquid organic fertilizer solution is prepared from one glass of ashes mixed with ten liters of water. Cucumber plantings are watered with this liquid, but you can’t overdo it here, otherwise the fruits will give off bitterness. But tomatoes, on the contrary, respond to feeding with sweetness, juiciness. Ash solution is useful for vegetable seedlings, especially cabbage. He will save young shoots from rot, strengthen them.
  3. Many gardeners add the ashes to the compost in order to use it later in growing early crops of cucumbers and cabbages. nine0014

Recommendations for the use of ash as a fertilizer

The basic rules for applying fertilizer in the form of ash include the following: .

  • Before sowing grass on the lawn, dry ash is distributed over the area, followed by digging.
  • Under apple trees, pears apply pure fertilizer into the groove created around the trunk. They feed garden trees, shrubs once every three years, two kilograms of ash per specimen. After this, abundant watering is required. nine0014
  • Cabbage should be fertilized organically frequently, preferably every ten to twelve days. Then the heads of cabbage will be whole, juicy, and the vegetable will be saved from the keel.
  • Several times during the summer it is necessary to fertilize the grapes with ashes. It is better to do this in the evening, spraying the ash solution on the leaves of the plant. It is made from one part of the ash and five parts of the liquid.
  • Spray the flowers in the rose garden in the same way. Before use, do not forget about mixing the fertilizer so that the phosphorus contained in it does not settle to the bottom. nine0014
  • Indoor flowers are best fed either with a dry product, a tablespoon per large pot, or with a solution of two tablespoons of ashes mixed with six liters of water. When applying fertilizer, care must be taken not to burn the root system of plants with it.
  • Wood ash is used against wireworm, cruciferous flea. To destroy the latter, the ashes must be mixed with tobacco dust, sprinkled with a mixture of diseased plants.
  • Ash can be used to feed potatoes: it helps to increase the yield, saves from pests. During the planting of the vegetable, along with the planting material, a teaspoon of wood ash is poured into the hole. A small amount of fertilizer is needed due to the fact that the acidity of the earth can decrease, and potatoes do not like this. nine0014

    Fertilizer is also indispensable for changing the composition of the soil. Only three hundred grams of fertilizer per square meter will improve the fertility of loamy and clay soils. It is able to balance the acidity and alkaline component of the earth in the area. Before applying fertilizer in the form of ashes, you need to know whether this can be done or not.

    When not to use ash top dressing

    But, like any product, ash has contraindications for use. Since this fertilizer contains a lot of potassium, calcium, with an excess of these elements in the soil, the introduction of ash will only bring harm. Plants will help to find out about this: their leaves fall off or become discolored, shoots die off on tomatoes, and grapes and apple trees are covered with excess leaf rosettes, fruit fruits begin to turn brown.

    Learn more