How Is a Fig Fertilized?

Soil Fertility

• Figs require a soil pH between 5.5 and 6.5. Improper pH levels in the soil cause figs to grow poorly and inhibits their ability to access nutrients in the soil. A soil test performed before planting determines the pH level. Soils with low pH levels require a lime amendment before you plant the fig tree to elevate the pH to the proper level. The soil test provides a guideline for how much lime to apply. Spread the lime over the planting site at least four weeks before planting fig. Turn the lime into the top 12 to 18 inches of the soil with a power tiller or spade.

Determining Fertilizer Needs

• Fertilizer needs vary depending on the nutrients already available in the soil. A soil test provides an exact guideline on fertilizer needs. If you don't perform a yearly soil test, fertilize figs lightly because over-fertilization can damage the plants more than too little fertilizer. Figs that grow poorly, develop weak or yellow leaves, or fail to fruit well typically require fertilization. A light fertilization in spring as new growth begins, in May and again in July ensures the figs receive nutrients throughout the productive season.

Fertilizer Types

• Figs primarily require nitrogen for good growth and fruit production. They also benefit from the application of phosphorus, potassium and trace nutrients. A special fertilizer isn't required. Use a balanced formula, such as an 8-8-8 or 10-10-10 blend. Apply slow-release fertilizers. These fertilizers come in a granule form that releases nutrients into the soil slowly over a period of eight to 12 weeks. The slow release of the nutrients ensures the fig roots aren't damaged or burned by too much nitrogen applied too quickly. Nitrogen dilutes slowly into the soil.

Application Method

• If you don't perform a soil test to determine the fertilizer amount, use 1 ½ oz. of fertilizer on figs that are 1 year old and 3 oz. on those that are 2 years old. Increase the amount to 1/3 lb. of fertilizer per foot of fig height on plants between 3 and 5 years old. Mature figs that are older than 5 years only require a once-yearly spring application of ½ lb. per foot of height, to a maximum of 5 lbs. per fig. Sprinkle the fertilizer in a circle on the soil surface around the trunk. Make the circle 18 inches in diameter the first year, and increase it to 24 inches in diameter in subsequent years. Water the soil thoroughly after each fertilizer application.