Fig Tree Soil Conditions

Nutrients

• Compared to most other fruit trees, the edible fig has relatively low needs for nitrogen. In fact, fertilizing the tree with nitrogen usually leads to long, leafy branches with very little fruit. The tree responds well to applications of potassium fertilizer, however. It can be applied in the form of potassium sulfate in late winter. Use 1 cup of potassium sulfate per 1 inch of the tree's trunk diameter, sprinkling it on top of the soil over the tree's root zone. Saturate the area with water to wash the fertilizer into the soil.

Soil pH

• Soil pH is a measure of the soil's relative acidity or alkalinity and is expressed on a scale of 1 to 14. A pH of 7 is considered neutral; higher values represent alkaline conditions, and lower values mean the soil is acidic. An edible fig tree performs best in slightly acidic soil, 6 to 6.5 pH. Extremely acidic soil can be remedied by adding dolomitic lime at a rate of 7 pounds per 100 square feet of soil area to achieve a pH increase of one point. Alkalinity can be lowered by applying 15 pounds of aluminum sulfate per 100 square feet of soil area to lower the pH level by one point.

Moisture

• A mature fig tree does not need to be watered except in the most arid environment, but a newly planted tree requires regular irrigation to become established. Watering the tree's soil deeply and infrequently is better than watering regularly but superficially. Watering soil deeply encourages the tree's roots to grow downward in search of soil moisture, which makes them become drought-tolerant and better anchors for the tree during high wind. The edible fig grows well in almost any soil type, including heavy clay and sandy soil. Drainage is important, however. Plant the tree on a slight mound if its planting site is in a low-lying area.

Pests

• A fig tree has notoriously tender, fleshy roots that are favored by gophers and other ground rodents. In an area where those pests are a threat, the fig tree's root should be protected by wire cages. The size of each wire cage's holes should be no more than 5/8 inch. The holes in standard chicken wire are too large, but specialized "gopher wire" is available. Hardware cloth with 1/2-inch holes is also effective for making wire baskets to protect the roots of a fig tree. The baskets should be at least 16 inches in diameter and 20 inches deep. Allow the top 4 inches of each basket to extend above the soil to prevent rodents from getting inside the basket from the soil surface.