Is Wood Ash Good for Flowering Plants and Fruit Trees?

Wood that has been turned to ash still has useful qualities. One of the best is putting wood ash around fruit trees and plants.

Because of the potassium that wood ash contains, it can provide a powerful nutrient that assists with the fruiting and flowering of such trees.

However, the amount of potassium that wood ash contains will vary depending on the type and age of the wood that was burned.

Also, the younger trees tend to have more potassium than the older ones. So, you should be cautious enough not to use more than what is required.

In This Article We Will Cover:

Do Roses Like Wood Ash?

Roses do great with wood ash, thanks to their properties.

Roses and many other flowering plants alike need nutrients like calcium, magnesium, phosphorous, potassium, and nitrogen in order to grow at their best.

These nutrients will not only encourage the healthy growth of the rose plants, but they can also encourage stronger stems and stronger roots.

Wood ash is alkaline, which is helpful for roses that are grown in acidic soils.

Why is wood ash good for roses?

Roses grow most efficiently in soil that has a pH of 6-7, and the wood ash works to neutralize it to where it needs to be.

The best time to put wood ash on or around the roses is before the start of the growing season, meaning at the beginning of spring.

The potassium in the wood ash will encourage the healthier growth of flowers to make sure they look their best when they finally bloom.

Applying the ash at this time will also let the water-soluble potassium get down to the roots to help promote flowering.

How much wood ash is good for flowering plants?

The difficult part of using ash is deciding how much of the ashes you want to put in the soil at once.

The amount of wood ash to add to the soil depends on the current pH of the soil before application. Test the soil by using a pH testing kit from a garden center or department store.

With its reading, you’ll be able to determine whether or not applying wood ash would help or hurt the roses.

When it comes to growing roses, specifically if the pH is less than 6.0, think about adding a bit of wood ash to lift the pH to a healthier range for these flowers.

If the reading is between 6.0 and 6.9, you don’t need to add any ash. Otherwise, this could make the soil more alkaline, something that isn’t good for roses.

Benefits of Wood Ash for Fruit Trees

The contents of wood ash help with strengthening the roots.

Another benefit is the ash bolsters an alkaline environment around the fruit trees that helps them grow better.

When composted, you can also use the ash as mulch which works not only with fruit trees but with vegetables and ornamental plants as well.

Below is a detailed breakdown of the advantages that you get from using wood ash around your garden plants.

1- Fertilizer Nutrients

Wood ash does more than add alkaline to the soil. It also harbors important nutrients such as the following.

Calcium
Iron
Magnesium

Phosphorus
Potassium

All these elements are important for the growth of healthy trees.

Additional elements, which include boron, molybdenum, chromium, and zinc, also assist in producing trees that grow faster and healthier.

2- Regulation of Soil pH

Containing high amounts of calcium carbonate, wood ash offers plenty of alkalinity for the soil. This creates the perfect environment for the growth of fruit trees.

However, it should be noted that some fruit trees thrive in more acidic soils.

Wood ash is the perfect additive when the soil is too acidic. Ideally, you want the soil to range from 6.0 to 7.5 on the pH scale.

Wood ash is perfect when you want to maintain a proper balance between alkaline and acidic in nature.

3- Cheaper Form of Lime

Lime is arguably the most commonly used element to control the level of pH in the soil.

Lime adds alkaline to the soil, which makes it less acidic. However, lime tends to be more expensive, which is why wood ash is generally better in terms of cost.

The only downside is that it takes twice as much wood ash compared to lime to achieve the same effect.

Still, the soil will become less acidic when using wood ash which you can either purchase or create by burning wood in your fireplace or campfire.

4- Destroys Pests

In addition to providing healthy nutrients, wood ash also contains elements that help prevent the infestation of pests and diseases.

There is salt in wood ash that dries out and destroys pests such as slugs, snails, and other invertebrates that are soft-bodied.

The result is that such pests are desiccated when coming into contact with the salt.

In addition, the wood ash masks the presence of plants from pests which makes them more difficult for such bugs to locate.

It also helps in driving away other bothersome pests such as grasshoppers, caterpillars, cutworms, and the like.

You can help protect your plants and fruit trees when sprinkling wood ash around.

5- Bolstering Compost Heap

Fruits are excellent for composting, but they do contain lots of acidic qualities. By mixing it with wood ash, you can reduce the amount of acidity in the compost.

If you do not want to reduce the acidity by much, then only use a moderate amount of wood ash.

This will allow good bacteria or worms that provide benefits to the soil.

For reducing acidity, a little wood ash can do the trick. By mixing it with compost, you can properly manage that level of acidity in the manner that you want.

This will work well with plants such as peas, beans, and root vegetables in addition to fruit trees. Apple trees do quite well when the soil is made somewhat less acidic.

How Can I Use Wood Ash in My Garden?

Wood ash fertilizer works best when it is lightly scattered or combined with the rest of the compost material.

It makes an excellent companion for the compost heap since it assists with plant fertility due to the nutrients it contains.

If you have a good deal of acidic material in your compost material, including fruit waste, the ash may help lower the pH of the compost and provide the lime the veggies will need later on.

The wood ash also brings out salts and lye if it becomes wet. In small amounts, the salt and lye won’t cause any issues.

On the other hand, large amounts of ash are not recommended. Composting fireplace ashes will let the salt leach away before use.

Adding too much ash at once might raise the pH too much, which could negatively impact the worms and bacteria in the compost.

Instead of dumping it all at once, you can keep the ash in a container and occasionally sprinkle it on a layer.

Method 1- Use as a Substitute for Lime

Garden lime is commonly used to raise the pH levels of the soil in places that are quite acidic. It turns highly acidic soil into more alkaline soil to promote a healthier growing environment.

Much like lime, ashes are quite alkaline and can foster similar results. You can substitute the lime for the ash and achieve the results you’re after.

Hardwoods tend to produce more ash and also retain more nutrients than softwood varieties.

Either way, ashes from both kinds of wood can alter the pH of the soil, just at different speeds. Bonfire ash tends to be even more variable due to the mix of plant types.

Before you start tossing any kind of ash on the compost pile in place of lime, check the soil in your garden so you know what it needs before applying the ash.

If the soil is already full of potassium, there is little point in adding any ash since too much of it can make it harder for the plants to take in any other nutrients.

Method 2- Add It Directly to the Soil

You can add ash right to the soil without first having to compost it.

Even though sprinkling the ash right onto the soil may at first repel snails and slugs, this effect will be gone; the first time it gets wet.

Some people recommend sprinkling this ash whenever you sow carrots or sprinkling it on turnips to keep flies away.

In order to make the most efficient application, use a rake. Be sure you aren’t leaving it in little piles or lumps, or else the excess salt can seep into the soil and make it harmful to plants.

You may also want to sieve the ash before you use it to filter out any large debris like charcoal. When doing so, avoid breathing in the dust.

Wear a mask and limit exposure to the skin by putting on work clothes, gloves, and boots.

Furthermore, don’t leave the wood ash out in the rain. Otherwise, the potassium will become soluble and can easily leak out.

Avoid any ash that comes from a fire that burns cardboard, coal, trash, or painted/stained wood.

The toxic chemicals in these materials can leach out into the ash and run the risk of harming your garden.

Which Type of Fruit Trees Like Wood Ash?

There are many types of fruit trees that benefit from the addition of wood ash.

Some of the trees include the following.

Dessert Apples and Redcurrants

Pears, Gooseberries, and Blackberries
Citrus Trees, Plums, Apricots, Cherries, and Blackcurrants

Keep in mind that some fruits, such as berries, only need a little wood ash.

Plus, there are fruit trees such as cherries, plums, and stone-fruit trees that grow quite well in slightly acidic soils.

So, just a dash of wood ash would be preferred for such trees. They would benefit from the nutrients that wood ash delivers as well.

To be on the safe side, you will want to test the soil first before adding any wood ash.

If you find the soil too acidic, then adding some wood ash would be beneficial to almost all fruit trees.

Wood ash also helps broccoli and cauliflower become protected from clubroot disease.

This means a good sprinkling of wood ash would be perfect. Plus, plants that need more potassium would benefit from wood ash as well.

This includes plants that clearly have discolored or brown leaf edges, which indicates a lack of potassium in the soil.

Which vegetables and plants do not like wood ash?

Usually, acid-loving plants such as raspberries, strawberries, and blueberries do not love wood ash from firepits and stoves.

A few other acid-loving plants where you should avoid spreading the ash include rhododendrons, azaleas, camellias, holly, potatoes, and parsley.

Also, keep in mind that there are trees such as apples, pears, peaches, and citrus trees that do not like alkaline-dominant soil.

So, if the pH test shows that the soil is more alkaline than acidic, you probably want to avoid using wood ash.

Only when the soil is acidic will a little bit of wood ash be beneficial.

It will not be enough to radically change the pH balance of the soil while providing much-needed nutrients.

Interestingly enough, there are a few fruit trees that actually like alkaline-dominate soil.

They are mostly fig trees which could benefit considerably from the addition of wood ash, especially in soil that is more acidic in nature.

Changing it over to alkaline would help fig trees quite a bit, along with the following plants.

Arugula and Artichokes

Collards and Broccoli
Tomatillos

What Types of Wood Ash Should You Avoid Near Plants?

When using wood ash for plants and trees, keep in mind that not all wood ash is the same.

Wood that was chemically treated, for example, will still contain elements that will be harmful to the soil. This is why you should avoid the following…

Chemically Treated Wood
Pressure Treated Wood

Painted or Stained Wood
Bonfires
Wood Burned with Cardboard, Coal, or Trash

By including any of the aforementioned treatments, the ash will actually poison the soil instead of helping it to flourish.

Therefore, any wood ash you introduce as fertilizer or mulch should be free of all chemicals or added elements.

FAQs

Does Wood Ash Kill Weeds?

Wood ashes can indeed be used to take care of a weed problem.

Even though wood ash is primarily thought of as a friend of plant growth, it can also be used to get rid of the weeds that plague your crops.

Using too much wood ash may change the soil’s pH to become more alkaline, and you can use this fact to kill the weeds in the surrounding soil.

If you use too much wood ash to get rid of the weeds, you might accidentally ruin the soil of your garden and make it barren. For this reason, you should use the wood ash with caution.

To use it to get rid of weeds, use it by pouring a deep layer of the ash where you want to prevent the growth of weeds. This is a good idea in areas that are along rock or structural walls.

Remember that this method of using the ash is quite effective, but if you use too much of it, it can be damaging.

Is Wood Ash Good for Tomatoes?

Wood ash is excellent for growing tomatoes since they love potassium. As mentioned, wood ash is rich in this nutrient.

You can either spread it directly at the base of the tomato plants or compost them first. Although, the best way to feed the ash to the tomatoes is to make it some “tea.”

In order to make this tea, put about five pounds of ashes into a burlap bag and tie it closed.

Lower the bag into a 50-gallon garbage bin filled with a lot of water, as if you were dunking a large tea bag. Allow it to sit for four days.

After this, you can put the tea in a watering can and pour about a cup of it on a tomato plant once a week.

After the plants begin to flower, you’ll see just how well tomatoes and potassium get along.

Can Wood Ash Be Used for Grass?

Wood ash can absolutely be used for grass. The high level of potassium in wood ash benefits the grass as it does the tomatoes, but the main benefit is found in the high alkalinity level found in the ash.

Because wood ash has properties that are similar to lime, they are good for raising the pH of the soil.

Lawn grass usually prefers the soil to be slightly acidic with a range of 6 to 7, but high nitrogen fertilizers often lower the pH level in time.

A lot of soil has slightly acidic levels, and once the pH of the soil gets below 6, the plants are limited in their ability to soak up the nutrients they need.

This is especially true of iron, phosphorous, and nitrogen.

Once this happens, the resilience, health, and beauty of the lawn are sacrificed. If the soil is depleted of potassium or is too acidic, wood ashes are a way to help the grass grow.

Even so, you should take some precautions when working with and after the application of ashes.

Be sure that you are only scattering it lightly instead of dumping it onto the soil. You can also balance it out beforehand by composting it first.

Wood ash can produce salt and lye if it gets wet. Not all wood ash fertilizers are the same.

Be careful to keep the ash dry, and make sure you know where the ashes are coming from before you use them.

The kind of wood that is burned determines the nutrient content, so take extra care to figure out the source of the ashes.

Generally speaking, it shouldn’t kill the grass, but if you aren’t careful with its application, it very well could.

Final Thoughts

Wood ash from your fire pit is perfect to use around fruit trees and garden plants. But before you apply wood ash to the soil, be sure to test its pH balance.

Soil that is mostly alkaline in nature probably would not benefit from the presence of wood ash.

However, soil that is mostly acidic will respond positively to a sprinkling of wood ash. It will help most plants to ward off pests and diseases while providing much-needed nutrients.

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Hi, I am Mark Garner a professional carpenter, woodworker, and DIY painter. I live in the small city of Peoria, Arizona as a semi-retired woodworker. I have started this blog with a simple motive to help you with my wood experience in this sector. If you like to know more about what I love doing and how it all got started, you can check more about me here.