Got the Winter Blues? Try Growing a Citrus Indoors

By Ann M. Mason, Fairfax Master Gardener Intern
Lemon Citrus in containerWinter in our Virginia zone 7 gardens, with its periodic freezing temperatures, limits all but the hardiest of plants. At this time of year, I recall fondly visiting my Florida relatives with their bountiful, heavily laden citrus trees. Morning strolls in their postage size yard often found me plucking a ripe, juicy orange, lemon or grapefruit for immediate eating. How might we enjoy similar joys?

In the chill of winter, we look to add and cultivate plants that flower and fruit indoors. Citrus plants expand our choices beyond typical house plants. Not only sporting shiny, evergreen leaves, a citrus offers aromatic, edible blossoms and colorful, striking long-lasting fruit. Fruit should be harvested only when ripe and needed. Citrus fruit matures only on the tree.

So, how do we successfully grow citrus indoors? The experts are all clear. There are five key elements:

  1. Lots of light. A citrus tree does not go dormant. Thus, it needs at least five to six hours of direct sunlight in a south or southwest window. More light hours are better. Eight to 12 hours are ideal. A grow light can supplement and extend light hours. With lower light, the leaves will adapt but a citrus plant will not flower or fruit.

  2. Slightly acidic well-drained soil (pH 6 to 7). A citrus tree does not like wet damp roots; regular potting medium retains too much water. Use a cactus mix or an amended potting medium with 1/3 small pea gravel, pumice, turkey grit or inorganic materials (vermiculite, coir) to improve drainage. Deep infrequent watering every five to seven days is better than frequent, shallow watering. Better for the soil to stay on the dry side since a citrus will quickly die if it has soggy roots. Pots without drainage holes or pots in a tray of standing water will cause root rot and plant death. Cupped or yellowed leaves are a symptom of too much water. The ideal pot for a citrus is a deep pot with sufficient drainage holes. Sufficient drainage is more important than whether the pot is plastic, clay or of some other material. Shallow pots will not balance the plant or tree as its gets larger. A large tree on casters or a wheeled plant caddy will allow better movement in the home and between the indoors to the outdoors for the summer months. Water the citrus more frequently outdoors.