How To Adjust Soil pH In Raised Garden Beds

By: Shahraz Zali

If you have a raised garden bed, you know good soil's importance. Not only does the soil need to be fertile and rich in nutrients, but it also needs a good pH level. A raised garden beds with poor soil can lead to disappointing results, so it's essential to take the time to improve the pH level before planting anything. In this article, we will discuss how to improve soil pH in raised garden beds using organic methods. Let's get started!

What Do You Need To Know About pH?

test soil pH with several soil ph tester

pH is a measure of the acidity or alkalinity of a solution. The pH scale goes from 0 to 14, with 0 being the most acidic and 14 being the most basic. Most plants prefer slightly acidic soil with a pH between six and seven. However, some plants prefer an alkaline soil with a pH between seven and eight. Therefore, it's important to know the pH preferences of the plants you want to grow before you start adjusting the pH of your soil.

How to Test Soil pH

There are three main methods to test soil pH in a garden bed:

pH Soil Meter

Insert the pH meter probe into the soil at various points in the bed (about 4-6 inches deep). Wait for the reading to stabilize, then note the pH value displayed.

pH Test Strips

Sample soil from different parts of the bed (about 4-6 inches deep), remove debris, and mix the soil with distilled water in a 1:1 ratio to make a slurry. Dip the test strip into the slurry, wait for it to change color, and compare it to the provided pH chart.

Simple Household Tests

These methods only indicate if the soil is acidic or alkaline, not specific pH values.

Vinegar Test: Place soil in a container, add a few drops of vinegar. If it fizzes, the soil is alkaline.

Baking Soda Test: Place soil in another container, add a few drops of water to moisten it, then add baking soda. If it fizzes, the soil is acidic.

For best results, test when the soil is moist but not waterlogged, and sample from multiple areas for an accurate average pH value.

Soil pH Control Good For Plants in Raised Beds

Improves nutrient availability for plants: When the pH is raised or lowered outside the plants' ideal range, certain nutrients become less available. This can lead to deficiencies in essential minerals, such as iron, manganese, and zinc.
Lowers toxicity levels: Alkaline or "sweet" soils can have high concentrations of heavy metals, such as aluminum and manganese. These can be toxic to plants, especially when the pH is raised above their ideal range.
Allows for better water uptake: Plants grown in soils with a pH outside their ideal range often have trouble taking up water. This can lead to wilting and stress during periods of drought.
Improves root growth: Most plants prefer slightly acidic soil (pH below 7). This allows for optimal root growth and development.
Increases resistance to some plant diseases: Some plant diseases, such as powdery mildew, prefer alkaline soils. Keeping the pH in the plants' ideal range can help prevent these diseases from taking hold.
Enhances decomposition of organic matter: Soil bacteria and fungi play an important role in the decomposition of organic matter. These organisms prefer neutral to slightly acidic soil (pH of 6 to 7). Decomposition rates can slow down when the pH is raised above or below this range.
Reduces soil compaction: Soil particles that are too close together can lead to compaction. This can make it difficult for roots to penetrate the soil and for water and air to move through it. A lower pH can help to loosen compacted soils.

How to Raise pH in Soil

Benefits Of pH Control For Plants-Vegega

There are numerous reasons why you might want to increase the pH of your soil. Perhaps your plants are not growing as well as you would like, or you notice that they seem lacking vitality. It could be that the fruits and vegetables you are harvestING from your garden have an unpleasant taste. Whatever the reason, there are a few different ways to increase the pH of your soil.

a. Adding Lime

One way to increase the pH of your soil is to add lime. Lime is a powdery substance made from calcium carbonate. It is available in two forms: agricultural lime and dolomitic lime. Agricultural lime is less expensive but takes longer to work, while dolomitic lime is more expensive but works faster.

To add lime to your soil, simply spread it over the soil's surface and work it in with a garden rake or hoe.

You should apply lime at least two weeks before you plant anything in your garden. This will give the lime time to work its way into the soil and adjust the pH. You should also have your soil tested before you add lime to it. This will ensure that you add the right amount of lime to raise the pH to the desired level.

b. Adding Wood Ashes

Another way to increase the pH of your soil is to add wood ashes. Wood ashes are a by-product of burning wood and contain high levels of potassium and calcium. Wood ashes also have a neutralizing effect on soil, which means they can help to balance out the pH.

c. Adding Compost

Adding compost to your garden is also an excellent way to increase the pH of your soil. Compost is made from organic matter, such as leaves and grass clippings, that bacteria and fungi have broken down. It is rich in nutrients and helps to improve drainage and aeration in the soil.

d. Mulching with Pine Needles

Mulching your garden with pine needles is another effective way to increase the pH of your soil. Pine needles are acidic, so they will help lower your soil's pH. You should apply a layer of pine needles about two inches thick. Be sure to replenish the mulch as it breaks down.

All these methods will help increase the pH of your soil and make it more hospitable for your plants.

How to Lower pH in Soil

Acidic soils have a lower pH than neutral soils, with a pH of around seven. Acidic soils are found naturally in areas with high rainfall, like the Pacific Northwest. But you can also find them in raised garden beds, especially if they're made of metal. Here are three ways to decrease the pH of your raised garden bed's soil.

1. Add Organic Matter

One way to decrease soil pH is to add organic matter. This can be done by adding compost or mulch to your raised bed. The organic matter will help lower the soil's pH over time.

2. Acidic Amendments

Another way to lower soil pH is to use acidic amendments. These amendments can be found at your local gardening store. Some examples of acidic amendments include sulfur, aluminum sulfate, and iron sulfate.

3. Use Plants That Prefer Acidic Soils

The last way to decrease soil pH is to use plants that prefer acidic soils. These plants can help to lower the pH of the soil around them. Some examples of plants that prefer acidic soils include azaleas, rhododendrons, and blueberries.

If you have a raised garden bed with metal sides, it's important to keep an eye on the pH of your soil. Following these three tips ensures that your raised garden bed has the perfect pH for your plants.

How To Adjust Soil pH In Raised Garden Beds?

If your raised garden bed is Zinc-Aluminum-Magnesium steel metal beds, you may need to adjust the pH of the soil in order to ensure optimal plant growth. The best way to do this is to use a soil test kit to determine the current pH level of the soil. If the soil is too acidic or too alkaline, you can use the tips we've mentioned below to adjust the pH level. Once the desired pH level is achieved, you can then plant your plants and vegetables.

If your raised beds are made from galvanized steel, they may leach zinc into the soil. Zinc is an essential plant micronutrient, but too much can be toxic. The best way to avoid this problem is to line your metal raised garden beds with a material that will prevent the metal from coming into contact with the soil.

Here are some tips for adjusting pH in metal raised garden beds:

Add lime to raise pH.
If your soil is too acidic, adding lime will help to raise the pH and make it more neutral. You can find lime at most garden centers or online.
Add sulfur to lower pH.
If your soil is too alkaline, adding sulfur will help to lower the pH and make it more acidic. You can find sulfur at most garden centers or online.
Amend the soil with organic matter.
Adding organic matter to your soil will help to improve drainage and aeration, which can also impact pH. Compost or well-rotted manure are both good options.
Test the soil regularly.
The best way to keep on top of pH is to test the soil regularly and make adjustments as needed. You can find pH testing kits at online stores.

Metal raised garden beds don't have to be a pain regarding pH. By following these simple tips, you can get your metal raised garden beds to the perfect pH in no time! Happy Gardening! Read about How to Choose the Best Soil for Raised Garden Beds!