You may wonder how you can tell if your blueberry bushes need fertilizer. Maybe you don’t know what kind of fertilizer to use or when it should be applied. I have wondered these same things and now that I have been growing blueberry bushes for a few years, I’d like to share what I’ve learned about fertilizing blueberry bushes.
Blueberries and Soil pH
Bl5.5. Ideally, they prefer the pH to be in the range of 4.5 to 5.0. If you aren’t sure of the pH value of your selected planting site, take a soil sample to the local extension office. If you need to make substantial changes to your soil, it is best to hold off planting for a year or two for the best results. Organic matter and fertilizers as well as other amendments can be used to raise or lower the pH.
Planting New Bushes
Once the pH is right, bushes can be planted the following spring. It’s a good idea to wait about 4 weeks before adding fertilizer. Standard fertilizer ratios for blueberries are 20-0-10+5 (N-P-K-Mg). All you need is 1 ounce per the topsoil about 12 to 18 from the plant, making sure it does not come in contact with stems or crown.
What About Older Bushes?
Blueberry bushes are extremely sensitive. Before adding fertilizer, take another soil sample in for testing. Any nutrient deficiencies will be revealed and you’ll receive recommendations on correcting them. Most older bushes need only some supplemental nitrogen. You can use uresaif the soil pH is lower than 5.0 or ammonium sulfate if it is higher than 5.0. Application should be made in the spring before buds emerge. Use the banding method. Place a wide band on both sides of the bush about a foot away from the stems.
What Else Might My Blueberry Bush Need?
Occasionally soil tests will show a deficiency in one of the other nutrients blueberry bushes need. Typically, potassium is the next most frequently deficient nutrient. Add potassium as 2-1-1 complete fertilizer that also provides the proper amount of nitrogen. For any other deficiencies, follow the guidelines given with your soil test results.
Organic Matter as Fertilizer
Organic matter like peat moss or sawdust can help keep soil loose which allows roots to move through the soil more easily in search of water and nutrients. Your soil should have at least 2% organic matter. How can you tell? You probably guessed. The soil test will show you. If the soil test shows less than 2 %, work some eat moss or sawdust into the soil before planting. The amount should cover a 18 inch wide band about 3 to 4 inches deep over the planting site. Using a shovel or rototiller, work it into the soil in the fall.
Stages of a Blueberry Bush Growth
How to Dehydrate Blueberries
Growth of Wild Blackberry Plants
Best Soil Conditions for Growing Blackberries
Sources: Personal Experience
Michigan State University: Hints on Growing Blueberries
Ohio State University: Growing Blueberries in the Home Garden