An ounce of prevention is worth a pound of cure, or so the old saying goes. Nowhere is this truer than in the care of citrus trees. Citrus trees are tropical evergreen trees and shrubs that bear tart, segmented fruit with leathery skin, including lemons, lime, grapefruit and oranges. Citrus trees may suffer from a wide range of problems that include damage from insects, diseases, rot and frost. Most of these problems can be prevented with proper cultural practices.
Plant new citrus trees in well-drained soil and place the root ball higher in the soil than its original planting depth to promote good drainage. Citrus trees cannot tolerate standing water. If a citrus tree is planted in poorly drained or waterlogged soil, it may develop root rot.
Water citrus trees whenever the soil becomes too dry to support the tree. Citrus are grown in some of the warmest parts of the world and often require watering from supplemental sources more often than trees grown in milder climates. Trees that do not get enough water become unhealthy and are open to more diseases than healthy trees. To tell when a tree needs water, insert your finger into the soil around the roots of the tree. Water whenever the soil feels dry at 1 inch below the surface.
Schedule regular applications of insecticides and fungicides for your citrus tree to prevent infestation with insects such as scale, mites, thrips and leaf roller caterpillars as well as fungal diseases including greasy spot, scab and melanose.
Drape citrus tree canopies with plastic tarps, quilts and blankets to help protect them from freezing weather. Remove mulch from the base of trees so that the soil can absorb heat during the day and transmit it down to the roots during the night. Anchor the coverings during freezing weather and pull them back during warm, sunny days to avoid overheating the tree.
Cultivate around the base of citrus trees to prevent establishment of weeds that can compete for nutrients and water resources. Well-nourished citrus trees that receive all the resources they need will resist problems better than unhealthy trees.