Do Raspberries Need to Be Fertilized?

Fertilizer

• The exact determination of proper amounts of fertilizer and lime is best done with a soil test, recommends the Ohio State University Extension. Generally, apply a pound of 10-10-10 fertilizer for every 100 feet of planting row 10 days after planting and then again after 30 days. Following this schedule, fertilize the plants in March and then in May.

Soil

• Though raspberries adapt well to a variety of soil types, growth is optimal in a sandy loam. Amend soil well with organic material and required nutrients prior to planting. Make sure that the soil is well-drained with the pH ranging between 5.8 and 6.5. In poorly drained areas, it is recommended to plant in raised beds. Applying an organic mulch will help conserve moisture in well-drained sites. Avoid mulch in slower-draining soils because it promotes infection from root rot fungi like phytophthora.

Site

• Select a site that receives full sun for best growth. Do not plant in low-lying areas that take longer to warm up during spring. Avoid planting in sites where peppers, potatoes, tomatoes or eggplants had been cultivated in the past four years. The high susceptibility of these crops to verticillium wilt also predisposes raspberries plants to the infection. Also do not plant raspberries within 600 feet of wild raspberries or blackberries.

Planting Suggestions

• Plant dormant raspberry canes in spring four weeks prior to the last frost date in the area. In case plants arrive early or if the soil is still too wet, store the well-wrapped plants in a cool place. Space the red raspberry canes 3 feet apart with a row space of 8 to 10 feet. Plant black raspberries 2 ½ feet apart with 8 to 10 feet of row space. Adequate row spacing is essential to promote air circulation that helps to reduce chances of fungal infections.