How to Fertilize Blueberry Bushes
Blueberry bushes aren't one of the easiest plants to grow, but if soil acidity and drainage conditions are right then the plants should produce abundant fruit. Decomposed organic mulches along with nitrogen can be added to keep the mulch from decomposing even further. The mulch is good for the plants as long as it's not a fresh material, because that can actually damage blueberry bushes in your home garden.
Step 1 – Start Preparations Early
The best time to start fertilizing blueberry bushes is a year or two before you plant them. Working organic matter into the soil, continued weeding and careful correction of the pH balance can be done over time and once the conditions are right planting can begin.
Step 2 – Measure pH Level
Check the pH level of the soil. It should be between 4.5 and 5.1, though it can be a little higher if other conditions are favorable. To lower the pH, sulfur or aluminum sulfate can be added. For the home garden, about three-quarters of a pound of elemental sulfur per 100 square feet is a good measurement. If the soil is very loamy, it could take up to 2 pounds, and clay soil will probably need 3 pounds per 100 square feet. This could take six months to show improvement.
If the pH is very high, the process to lower it can prove costly and time-consuming. If you haven't already planted blueberry bushes, you should find another spot with a better pH level. If you've already planted, you may consider replanting, especially if lime is present because the pH will probably never stay within the desired range. If the soil is too acid with a low pH, dolomitic lime can be added to bring the level up.
Step 3 – Check the Density of the Soil
The soil can be heavier and denser if the pH level is correct. Otherwise blueberry bushes will do best in a soil that's rich with organic matter, like a soil that contains mixture of sand and peat. It has to be a soil that drains well, as blueberry plants can easily be damaged by water standing around the roots.
Step 4 – Maintain the pH Level
In areas where you've had to make pH corrections because of alkaline soil, add ammonium sulfate after planting to increase nitrogen and keep the level correct.
Step 5 – A Fertilizer Schedule
As long as you maintain the pH balance of the soil, a complete fertilizer should be sufficient. Fertilize young blueberry plants individually, and fertilize for the first time a month after planting. Spread an ounce of fertilizer that contains 20% nitrogen around each plant, taking care to keep it away from the stem. Adult plants can be fertilized with an applicator, if desired, and the amount of nitrogen fertilizer can be increased to 5 ounces per plant. Fertilize only when the plants are dry so as to avoid particles from sticking the plants and doing damage. Fertilizing blueberry bushes in the early spring before foliage appears is ideal.