When Should You Fertilize Blueberry Bushes?

Where to Plant

• Blueberries will grow in most gardens with acidic soil. Although they can tolerate full sun, they do best in an area that is shaded during the hottest time of day. Avoid planting blueberries where they will be heavily shaded most of the day. Most blueberries do best planted in the ground, but some varieties have been cultivated to grow well in pots.

Soil Conditions

• Blueberries planted in soil with a pH greater than 5.5 have difficulty taking up nutrients, and fruit production will suffer. The best pH for blueberries is 4.0 to 5.0. If your soil pH is higher than this optimal range, amend the soil with peat moss or pine needles to increase the acidity. Regardless of how much fertilizer you apply to your blueberries, if they aren't planted in acidic soil, the roots can't take in the nutrients efficiently.

When to Fertilize

• Blueberries planted in a good location and in acidic soil don't require heavy feedings. Fertilize once in early spring when the shrubs come out of dormancy and start to produce leaves. Fertilize again when flower buds begin to appear in May or June. Do not fertilize blueberries after July.

Type of Fertlizer to Use

• Good fertilizers for blueberries are high in nitrogen and potassium with a moderate amount of phosphorus and micronutrients. Fertilizers specifically intended for rhododendrons are ideal for blueberries since both plants require similar growing conditions. Blueberry plants with leaves that have turned yellow need iron in the form of iron sulfate or iron chelate. Yellow leaves signal that the soil is not acidic enough for the blueberry plant.