Soil Test Results
Soil tests do not measure the total amount of nutrients available in the soil. The tests measure the nutrients that are expected to become available to the plant. Recommendations for improvement are given in the test results. To get the most of raspberry soil tests, you should:
- Add a nitrogen fertilizer at the recommended time and rate.
- Correct your soil’s pH if needed.
- Add potassium or phosphorus containing source only if the levels are low.
Before fertilizing new raspberry canes, correcting the soil’s pH should be done if necessary. This correction may take up to a year. If the soil’s pH needs to be lowered, use sulfur. Lime or wood ashes will raise the pH of the soil. Recommended levels of these amendments should be added to the top 4 to 6 inches of soil.
Soil preparation should include adding organic matter such as animal or plant by-products, composted manure, plant-based compost, and peat moss. Nutrient and water-holding properties are increased by these. Ideally, organic matter should be added to the soil a year ahead of planting raspberries. Nitrogen from organic matter is not fully available to plants for 6 to 9 months.
The greatest nutritional needs for raspberry bushes are nitrogen, phosphorus, and potassium. The best way of supplying these needs are using these:
- Blood Meal (good source of nitrogen)
- Fish Emulsion (good source of nitrogen, phosphorus, and micronutrients)
- Hydrolysed Fish Fertilizer (good source of nitrogen, phosphorus, and potassium)
- Fish Meal (good source of nitrogen, phosphorus, and potassium)
- Kelp (good source of potassium)
- Green Sand (good source of potassium)
- Organic Cow Manure Pellets (good source of nitrogen)
- Chicken Manure (good source of nitrogen)
Timing of Fertilizing
Before planting for the first time, an organic fertilizer high in nitrogen should be added and mixed well into the top 12 inches of soil. At planting time, a handful or recommended liquid amount of fertilizer should be applied around (not touching) each bare-root. Mix in sources of potassium or phosphorus only if the soil test indicates the need.
Raspberry bushes should be fertilized every spring when the canes begin to bud. This should be sufficient for a bountiful crop of raspberries.