Feeding Southern Higbush blueberry bushes is quite simple...
Do not fertilize a newly planted blueberry bush until new growth begins to emerge during the first spring. DO NOT fertilize blueberry with fertilizers that contain a nitrate form of nitrogen as this will damage roots. . When feeding blueberry bushes that were planted bare-root, and only 1-year old, apply 2 ounces of a granulated azalea fertilizer or 2 to 3 ounces of an organic plant food over an 18-inch diameter circular area with the plant in the center. If there has been good rainfall or if you irrigate regularly during dry periods, feed again at the same rate in May and July. Repeat this same feeding process in March and July of the second year with 3 to 4 ounces of fertilizer spread over a 24-inch diameter circular area with the blueberry plant in the center.
From the third season on, or when fertilizing older plants that were container-grown, base the amount of fertilizer applied on the size of the bushes. Follow application rates on product label and be sure to spread the fertilizer evenly under and around the bushes. Bushes 6 feet tall or taller should receive the maximum rate of 6 ounces of fertilizer per bush. Spread the fertilizer evenly under and around the bushes.
Soil pH is important!
Soil pH is also very important when growing blueberries. They like a very acid soil ranging from 4.5 to 5.1. If your soil is too alkaline your blueberries won't thrive and produce. If you're not sure about the soil pH in the planting area, you might want to test your soil using a test kit purchased from your local nursery and garden center or you can buy a soil pH test kit online here.
How can I make soil more acid?
Regarding growing blueberries, if your soil test indicates a soil pH anything above 5.1 you'll need to take measures to increase the acidity (lower the pH to 4.5 to 5.1). There are several products available you can use to make it more acid. Though it works a little slower, I've had the best success using Soil Sulfur, however chelated iron and aluminum sulfate can be used as well.
Other Tips
- Never over-fertilize blueberry bushes as too much fertilizer damages them easily. If you use an organic fertilizer there won't be the worries about burning your plants. I use Dynamite Organic All-Purpose Plant Food to fertilize my blueberries. It is OMRI Listed organic and ensures you won't burn your plants.
- Water the plants throughout the growing season when rainfall is not adequate. Irrigation of young plants is especially important. Adequate water is essential for plant growth and important for fruit bud formation that occurs in the Fall.
