Fertilizing Fruits

Key Points

• Fruit plants need adequate soil nutrients for good growth and fruiting.
• Test the soil before planting fruit plants. This is very important when planting blueberries. 
• Increase the organic matter content of the soil prior to planting. Organic matter enhances root growth, provides a wide range of nutrients, and increases the soil's water-holding capacity.
• Regular additions of organic matter will reduce the need for supplemental fertilizers.
• Follow fertilizer label directions.
• Plants under severe nutrient stress often decline and are more vulnerable to certain diseases and insect pests.
• Over-application of chemical or organic fertilizers can burn foliage and roots, stimulate leaf growth at the expense of fruit, and produce weak growth, prone to attack by diseases and sucking insect pests. Excess nutrients carried away by ground and surface water and can contaminate streams, lakes, and the Chesapeake Bay.
  
  Fruit Fertilizing Tips
  Fertilizer Recommendations
  Fertilizing Small Fruits
  Fertilizing Tree Fruits

Fruit Fertilizing Tips

• Most fruit plants are fertilized in spring at flowering.
• Broadcast fertilize when foliage is dry, and brush residual off leaves.
• Once plants are in the ground, do not disturb shallow roots by working fertilizer into the soil.
• Broadcast dry fertilizers over the root zone of fruit plants and water in fertilizers if rainfall is not expected.
• Move mulch away from plants/trees to fertilize to ensure direct contact with soil. Reapply mulch after fertilizing.
• Keep fertilizers from contacting the crowns (base) and lower stems of small fruit plants.
• Lawn fertilizers applied near fruit plants may reduce their fertilizer needs.
• Late summer and fall fertilization interferes with the hardening-off process and leads to winter damage. (Strawberries are an exception- they are fertilized in August)

Fertilizer Recommendations

• Nitrogen recommendations are listed below. Nitrogen is the major nutrient needed in the largest amount. Unlike nutrients that are part of the mineral soil, nitrogen is supplied through organic matter and fertilizers.
• Use nitrogen-only fertilizers like nitrate of soda (15-0-0), calcium nitrate (16-0-0), blood meal (12-0-0), and) and fish emulsion (5% N) or complete fertilizers (contain nitrogen, phosphorous, and potassium) that are high in nitrogen relative to the other nutrients like cottonseed meal (6-2-1 or fish meal (10-2-2).
• If you have your soil tested by a soil testing lab and your phosphorus and/or potassium levels are low, you will receive a fertilizer recommendation for supplying those nutrients.

Example: the recommendation is to apply 1.5 ounces of nitrogen per 100 sq. ft. and you want to supply the nitrogen using nitrate of soda (15-0-0).This fertilizer is 15% (0.15) nitrogen by weight.

1.5 ÷ 0.15 = 10 ounces of fertilizer 

Use Louisiana State University, (PDF)Tons to Teaspoons to convert weight to volume measurements.

Fertilizing Small fruits

• Strawberry (June-bearing)

Soil pH- 6.0
Year 1- fertilize with 0.30 ounces of nitrogen (N) per 10 ft. of row six weeks after planting and again in August
Year 2 and older- fertilize with 0.30 ounces of nitrogen (N) per 10 ft. of row in August

• Strawberry (day-neutral and everbearing)

Soil pH- 6.0
Year 1- fertilize with 0.90 ounces of nitrogen (N) per 10 ft. of row once a month, June-September
Year 2 and older- fertilize with 0.60 ounces of nitrogen (N) per 10 ft. of row once a month, May-September

• Raspberry/blackberry

Soil pH- 6.0-6.5
Year 1 and 2- fertilize with 0.80 ounces of nitrogen (N) per 10 ft. of row at flowering
Year 3 and older- fertilize with 1.6 ounces of nitrogen (N) per 10 ft. of row at flowering

• Grape

Soil pH- 5.8-6.5
Year 1- fertilize with 0.30 ounces of nitrogen (N) per plant at planting
Year 2- fertilize with 0.30 ounces of nitrogen (N) per plant at flowering
Year 3- fertilize with 0.40 ounces of nitrogen (N) per plant at flowering
Year 4- fertilize with 0.80 ounces of nitrogen (N) per plant at flowering
Year 5 and older- fertilize with 1.60 ounces of nitrogen (N) per plant at flowering

• Blueberry

Soil pH- 4.3-5.3
Avoid fertilizers containing nitrates or chlorides.
Year 1- no fertilizer
Year 2- 2.0 ounces of 21-0-0 (ammonium sulfate) per plant during bloom, and the same amount 3 weeks later. Scatter in a ring 12 in. to 18 in. from the plant.
Year 3 and older- increase by 1.0 ounce per year until the 6th year; then use 8.0 ounces per plant each succeeding year.

Fertilizing Tree fruits

• Apple and pear

Soil pH- 6.0-6.5
Year 1- broadcast 0.80 ounces of nitrogen (N) over a two-foot circle, one month after planting. Keep the fertilizer six inches away from the trunk and broadcast it evenly. Do not put any fertilizer in the hole before planting. Broadcast another 0.80 ounces of nitrogen (N) around each tree in June.
Year 2 and older- apply fertilizer in spring and increase the amount of nitrogen applied by 0.40 ounces per year up to a maximum of 4.0 ounces nitrogen (N) per tree (dwarf); 8.0 ounces nitrogen (N) per tree (semi-dwarf); and 1 lb. nitrogen (N) per tree (standard)
Reduce these fertilizer rates if trees become overly vegetative, producing more than 12 to 18 inches of new shoot growth per year).

• Peach, cherry, plum

Soil pH- 6.0-6.5
Year 1- fertilize with 0.80 ounces of nitrogen (N) per tree prior to planting. Do not place fertilizer in the planting hole.
Year 2 and older- broadcast 0.80 ounces of nitrogen (N) under each tree in early spring. Increase the amount applied by an additional 0.80 ounces of nitrogen (N) per year up to a maximum of 8.0 ounces per tree regardless of age.

Never fertilize after July 15. Late fertilization encourages soft growth which may be winter-killed and interferes with the trees over-all ability to harden-off for the dormant period.

Additional Resources

• Fertilizers
• (PDF) Tons to Teaspoons- Louisiana State University
• Add Organic Matter To Your Soil

Author: Jon Traunfeld, HGIC Director and Extension Specialist, Fruits and Vegetables.
10/2020