What to Use for Fertilizer on Raspberry Plants

Soil Preparation

• Before planting raspberries, prepare the soil well so it is fertile and well-drained. Plant a cover crop, such as clover or oats the fall before you plant raspberries. Dig this cover crop under in the spring. As it decomposes, it will improve drainage and add nitrogen to the soil. Alternatively, spread a 3- to 4-inch layer of compost or manure over the soil and dig it to a depth of 8 to 10 inches. Ensure these soil amendments are well-rotted to kill any weed seeds or pathogens. Raspberries prefer a soil pH of 5.6 to 6.2. Amend the soil with lime to raise the pH if indicated by a soil test.

General Fertilizer Guidelines

• Apply 2 oz. of 5-10-5 granular fertilizer to the soil around each plant two weeks after planting your raspberries. Thereafter, spread 15 to 20 lb. of a balanced granular fertilizer, such as a 10-10-10 formula per 1,000 square feet of soil or 1/2 cup around each plant. Apply half the fertilizer in early spring before new growth emerges. Make the second application four weeks later.

Organic Substitutes

• Apply compost, manure, blood meal, bone meal or rock phosphate as an organic alternative. Organic fertilizers vary in their nutrient composition. Read the labels and apply enough fertilizer to provide 2 lb. of nitrogen, phosphorus and potassium per 1,000 square feet of soil. Spread these materials in early spring as new growth is emerging.

Considerations

• In addition to proper fertilizing, good watering, pruning and weeding practices are essential to grow raspberries successfully. Raspberries need at least 1 to 2 inches of water per week to produce high-quality, abundant fruit. Drip irrigation systems conserve water and reduce the chance of diseases spread by wet leaves. Pull weeds by hand or hoe them lightly, taking care not to damage the shallow roots of raspberry plants. Mulch the raspberries with wood chips, saw dust or untreated grass clippings to minimize weed growth. Prune raspberries to remove dead canes in late winter.