Why Aren't My Lemons Getting Ripe on My Dwarf Tree?

Season and Temperature

• Aggie Horticulture notes that lemon trees are the most sensitive citrus trees, and suggests growing them only in protected locations. Purdue University goes on to state that the trees and their fruit fail at temperatures below 20 to 30 degrees Fahrenheit. Keep the tree in temperatures of 70 to 80 degrees F to encourage the best growth and fruit ripening.

Sunshine

• Lemon trees may grow and even bloom in partial shade. The fruit, though, requires full all-day sunshine to grow and ripen. If the tree grows in a shaded or cool location, and has trouble ripening its fruit, move it to a sunnier, warmer spot for better fruit ripening.

Nutrition

• Lemon trees require adequate year-round care to produce and ripen their fruit. Fruit may not ripen on trees with poor, tight or slow-draining soil. Mix organic compost into the dwarf lemon tree's soil for better nutrition and drainage. Aggie Horticulture also suggests maintaining good nutrition levels with monthly feeding from spring through fall. Use balanced or citrus-specific fertilizer according to the manufacturer's directions.

Water and Mulch

• All fruit contains high water content, and ripens best with adequate moisture. Give the dwarf lemon tree 2 to 4 inches of water every week to keep the soil moist for fruit growth and ripening. Lay 2 inches of organic compost over outdoor trees to keep the soil moist and warm during the growing season.