Soil Prep For Blueberry Plant: Lower Soil pH For Blueberries

Blueberry Plant Full Of Blueberries
blueberrys on the bush
(Image credit: Eike Leppert)

Many times, if a blueberry bush is not doing well in a home garden, it is the soil that is to blame. If the blueberry soil pH is too high, the blueberry bush will not grow well. Taking steps to test your blueberry pH soil level and, if it is too high, lowering blueberry soil pH will make a huge difference in how well you blueberries grow. 

Keep reading to learn about proper soil prep for blueberry plants and how you can lower soil pH for blueberries.

Testing Blueberry pH Soil Level

Regardless of whether you are planting a new blueberry bush or trying to improve the performance of established blueberry bushes, it is essential that you have your soil tested. In all but a few places, your blueberry soil pH will be too high and testing the soil can tell how high the pH is. 

Soil testing will allow you to see how much work your soil will need in order to grow blueberries well. The proper blueberry pH soil level is between 4 and 5. If your blueberry bush's soil is higher than this, then you need to take steps to lower the soil pH for blueberries.

New Blueberry Plantings - Soil Prep for Blueberry Plant

If your blueberry soil pH is too high, you need to lower it. The best way to do this is too add granular sulfur to the soil. About 1 pound (0.50 kg.) of sulfur per fifty feet (15 m.) will lower the pH one point. 

This will need to be worked or tilled into the soil. If you can, add this to the soil three months before you plan on planting. This will allow the sulfur to better mix with the soil. You can also use acid peat or used coffee grounds as an organic method of acidifying the soil. Work in 4-6 inches (10-15 cm.) of peat or coffee ground into the soil.

Existing Blueberries - Lowering Blueberry Soil pH

No matter how well you do soil prep for a blueberry plant, if you do not live in an area where the soil is naturally acidic, you will find that the soil pH will return to its normal level in a few years if nothing is done to maintain the lower pH around the blueberries. 

There are several methods you can use to either lower soil pH for blueberries that are established or to maintain the already adjusted blueberry pH soil level.

  • One method is to add sphagnum peat around the base of the blueberry plant about once a year. Used coffee grounds can also be used.
  • Another method for lowering blueberry soil pH is to make sure you are fertilizing your blueberries with an acidic fertilizer. Fertilizers containing ammonium nitrate, ammonium sulfate, or sulfur-coated urea are high acid fertilizers.
  • Adding sulfur to the top of the soil is another way to lower soil pH for blueberries. It may take some time for this to work on established plantings because you will not be able to work it far into the soil without causing damage to the blueberry bush's roots. But it will eventually work its way down to the roots.
  • A quick fix for when the blueberry soil pH is too high is to use diluted vinegar. Use 2 tablespoons (30 mL.) of vinegar per gallon of water and water the blueberry with this once a week or so. While this is a quick fix, it is not a long lasting one and should not be relied on as a long term way for lowering blueberry soil pH.
Heather Rhoades
Founder of Gardening Know How

Heather Rhoades founded Gardening Know How in 2007. She holds degrees from Cleveland State University and Northern Kentucky University. She is an avid gardener with a passion for community, and is a recipient of the Master Gardeners of Ohio Lifetime Achievement Award.