The Best Fertilizers to Grow Strawberries

Before Planting

• Since strawberries will occupy the ground for several years, good soil preparation before planting them is critical to strong, vigorous growth. Strawberries prefer light, well-draining soil. Spread 3 to 4 inches of rotted manure or compost over the soil. These amendments add nitrogen, phosphorus and potassium to the soil as they break down. They also improve the texture and drainage of the soil. Add lime, phosphorus and potassium as recommended by a soil test.

Young Plants

• Fertilize young June-bearing varieties when they begin producing runners with 1 cup ammonium nitrate or 1/3 cup urea per 100 feet of row. Make a second application in August. Fertilize ever-bearing and day-neutral types three weeks after planting and in midsummer with 1 tsp. ammonium nitrate or urea spread around the base of the plant. Water the fertilizer in after spreading and don't get it on the plants' leaves.

Mature Plants

• Ever-bearing and day-neutral strawberries may produce a small crop the first year, as strawberries begin bearing fruit in earnest the second year after planting. Do not apply fertilizer in the spring unless growth remains slow, because early nitrogen applications may produce soft fruit that is quick to decay. To improve vigor, give plants 1 cup ammonium nitrate or 1/3 cup urea for each 100 feet of row in June. Apply fertilizer in late July or August, depending on the variety, to promote strong growth for the following year. Do not apply fertilizer later than September. Doing so encourages new growth that cold weather will kill.

Considerations

• When selecting fertilizer for strawberries, choose a high-nitrogen formula. Urea and ammonium nitrate are inexpensive options, but any formula high in nitrogen and low in phosphorus and potassium works. Look for a 21-0-0 formula or similar. Consult a county extension office or nursery specialist for fertilizer recommendations for your area.