Amend the soil in your planting area with one part organic compost for each four parts of garden soil. The compost improves drainage, which citrus trees need, as well as providing nutrients to the soil.
Feed your citrus, whether it’s in the ground or in a container, four times each year, starting in spring and continuing at even intervals until mid summer. Use fish emulsion or make compost tea. Follow fish emulsion package instructions for correct mixing and application. Combine 10 cups compost with 5 gallons of water to make a tea; steep overnight, and then water your citrus tree with the mixture.
Treat soft-bodied insects such as aphids with a spray of insecticidal soap. It might be necessary to spray your citrus several times, every other day, before all insects are gone. Be sure to saturate both the top and underside surfaces of all leaves and stems.
Control scale insects and other hard-bodied insects with a spray of insecticidal soap into which you add 1 tbsp. of canola oil for every quart of spray. Hand picking is another effective method of control.
Scatter iron phosphate or diatomaceous earth on the soil surrounding your citrus tree, if snails and slugs are present in your garden. Rain and irrigation will dilute these products, so repeat your application after the area becomes wet. If you don’t mind doing it, hand picking snails and slugs also greatly helps to reduce the local population.