How to Save a Dying Grapefruit Tree in a Container

Check soil moisture levels. Push your finger a couple of inches into the soil. If the soil is soggy, you are probably over-watering the tree. Grapefruit trees need moisture but are not adapted to very damp conditions. Leave the soil to dry out before watering again. If the top couple of inches are dry, push a stick further into the soil and remove it. If the entire stick is dry, the grapefruit tree needs water. Fill up the saucer with water and replenish as it is drawn up into the pot. Water the tree more frequently in the future.

Lift the pot, if the tree is a small one, and look underneath. If roots are emerging from the holes in the bottom, the tree is pot-bound and needs repotting. Transfer it to another larger container, using general-purpose potting compost in the bottom of the new pot and around the sides. Fill the saucer with water.

Move the tree into a spot that receives plenty of light, but not intense direct sunlight for long periods, which can burn the leaves.

Examine the tree for fungi and pests. Grapefruit trees in containers are especially prone to damp, which leads to mold and fungus gnats, whose larvae eat plant roots. In general, citrus trees are vulnerable to aphids, mold, scale insects and whitefly. Although such pests don’t normally cause serious damage, they might further weaken a dying tree. Treat any infestations or infections with the appropriate products or methods. For example, treat fungus gnats simply by letting the soil dry out periodically or by spraying the soil with a solution of dishwashing liquid and water. Pick off larger pests or use a mild insecticide. Remove and burn any leaves with heavy fungal growth.

Fertilize the tree once or twice a month during the spring and summer with a nitrogen-rich houseplant fertilizer. Grapefruit trees need a lot of nutrients, and a dying tree may simply not be getting enough from the small amount of soil in a container. Use the maximum amount recommended on the packaging. Don’t fertilize outside the growing season.