How to Make Soil Acidic for Blueberries [5 Genius Methods]

Blueberries are acid-loving plants that need acid soil for best growth. If you only have neutral soil or alkaline soils, there are ways to increase soil acidity for your berries. Acidic fertilizers, soil acidifiers, and ammonium sulfate can all be used to augment acidic soils. Simply apply any of these as the instruction label specifies and then water into the ground. This will decrease the soil pH into it is the right level of acidity for blueberries.

What Soil Acidity is Right for Blueberries?

Blueberries thrive in soil with a pH from 4.5 to 5.5. This is much more acidic soil than other plants tolerate. To determine your soil acidity, use a soil meter to perform a test in several areas where you plan to plant blueberries. Remember, the lower the pH number is, the more acidic your soil is.

• A pH in the 4.5–5.5 range is ideal for blueberry growth.
• Before planting blueberries or amending the soil, check your soil pH with this soil testing kit.
• The lower the pH number, the more acidic your soil is.

If your soil’s pH is above 5.5, it should be amended with a soil acidifier product. In the rare case that your soil is too acidic for blueberries (if the pH is lower than 4.5), the soil acidity can be reduced by adding calcitic or dolomitic lime. Whenever you add an amendment to change the soil, retest the soil to make sure it is in the proper range for blueberries.

5 Ways to Make Soil Acidic for Blueberry Plants

Soil acidification is a relatively simple process that can improve the acidity of soil over time. First, you’ll want a soil sample to determine the type of soil you have. Then simply use one of these acidifiers below to improve the acidity of your soil as needed.

Acid Fertilizers

Acid fertilizers provide acidity directly when native soil isn’t acidic enough. Use this organic fertilizer for blueberries to provide acid directly to the roots. This solution works great if you’ve already planted your blueberry bushes only to find later that the soil isn’t acidic enough. By feeding your blueberries acidic fertilizer, you’ll boost blueberry health and production without changing your soil pH.

Soil Acidifier

Soil acidifiers differ from acid fertilizers in that they slowly change the acidity of the soil itself. This means you can turn any soil into ideal soil over time. Use this soil acidifier for blueberries to reduce the pH of your soil to acceptable levels. It’s best to apply a soil acidifier in stages. Re-test the soil after each application. It may take a few applications before your soil reaches the correct range.

Elemental Sulfur

Elemental sulfur is an organic soil acidifier that deserves special attention. It is one of the most natural and quickest methods to acidify your soil. Use this elemental sulfur to naturally reduce your soil pH level. By mixing or tilling sulfur into the soil, you’ll create a more acidic environment where blueberries thrive.

Peat Moss or Pine Needles

Certain natural plant debris can be used to alter the acidity of your soil. Acidic mulches like peat moss and pine needles break down into sulfuric acid which increases soil acidity. Be aware that not all peat moss increases soil acidity. Sphagnum peat can reduce soil acidity and is one of the more common peat types found at garden centers. Consider making a compost out of pine needles for a high-acidic treatment that will create ideal conditions for your blueberries.

Coffee Grounds

Fertilizing with coffee grounds is a great way to aid soil acidity and provide extra nitrogen. Make sure you only use spent coffee grounds (ones that have already been used to make coffee). First, spread spent coffee ground around your plant to spread beneficial nutrients and acidifiers. Then, mix the coffee grounds into the soil so that they decompose and release helpful acids into the soil.

Do Blueberries Need Acidic Soil?

Blueberry bushes need a soil acidity somewhere between a pH of 4.5 and 5.5. Any higher than this and your blueberry bushes will be sickly and yellow. Blueberries need acidic garden soil to promote the growth of soil bacteria that is beneficial to fruit growth. 

• A soil pH range of 4.5–5.5 ph is vital for abundant fruit growth on blueberry plants.
• Make sure to take a soil sample to ensure proper soil acidity when growing blueberries.

Acid-loving bacteria create minerals and release ammonia. Ammonia provides the best supplemental nitrogen source for blueberries. If you do not have acidic soil for planting, you can either purchase acidic soil or do soil preparation to increase acidity in the garden soil you do have.

When Should You Acidify Soil for Blueberries?

The best time to acidify your garden soil is prior to planting your blueberry patch. This ensures an acidic environment for the best growth right from the start. Add your soil acidifier in and near the planting hole a week or so before planting. The next best time to acidify the soil is shortly before your bush exits dormancy. This will allow the bush to get its essential nutrient uptake as early in the growth process as possible. 

• The best time to acidify your blueberry patch is prior to planting.
• The second best time is at the tail end of winter as your bush exits the dormant period.
• The third best time is a few weeks before berry production begins.

Lastly, you can acidify your soil a few weeks before blueberry fruit starts developing. This will help to make sure your fruit production goes smoothly and grows properly. Blueberries usually begin growing in June, so consider acidifying the soil in early May.

How to Make Your Soil More Acidic for Blueberry Plants

Acidifying garden soil for blueberries can be achieved with many effective methods. Any of these methods will help you grow taller blueberries and more fruit:

• Acid fertilizer helps provide needed acid directly.
• Soil amendments like soil acidifiers change the acid composition of your garden soil.
• Elemental sulfur is a particularly good soil acidifier.
• Peat moss or pine needles as mulch make great organic methods of acidifying soil. 
• Adding spent coffee grounds to your current soil provides acid and more nitrogen.

Be sure to try a few of these approaches to find the quickest methods of acidifying your garden. If you overdo the acidification, you can always mix agricultural lime into the soil to reduce acidity.