Lime Tree

Lime (Citrus × aurantiifolia) is a citrus tree, and Key lime is one of its named types. Many dwarf citrus trees sold for pots include limes. Key limes are smaller and a bit more acidic than Persian limes, and home gardeners tend to get a more reliable crop from Key limes.

Trees sold as dwarf or grafted stay compact, while full-sized citrus can grow over 20 feet tall. In containers, dwarf citrus usually reaches 3 to 5 feet (91 to 152 cm).

This draft has no reliable sowing date, sowing depth or germination time for lime seed, so it cannot give a sowing schedule. Citrus can be grown from seed taken from inside the fruit, but the fruit may be of lower quality. Seedlings will differ from the parent plant, so a named variety is the better choice. Seed-grown citrus seldom sets fruit, and when it does, the fruit is usually inferior. Seed-grown plants also tend to have long, sharp thorns and can grow too large for a pot.

Most gardeners buy a grafted tree, which stays more compact, often under 6 feet. Stem cuttings are the most reliable way to copy a named variety. Lemons and limes need 1 to 3 years to mature enough to flower, so a larger young tree usually fruits sooner.

Light. Place a lime in full sun, with at least 6 hours of direct sunlight a day, or more if possible (8 to 12 hours). Indoors, a south-facing window gives the strongest light, and supplemental grow lights may be needed. Plants that get less than 6 hours of direct light a day are very unlikely to flower and fruit.

Water. Keep the soil moist but never soggy, and let the top layer dry slightly between waterings. Don’t let the pot sit in standing water.

Temperature. Citrus grows best between 55 °F and 85 °F (13 °C to 29 °C). Most citrus is damaged when temperatures fall below 32 °F (0 °C), so bring potted trees in before frost.

Feeding. Fertilize at least three times in the growing season, in spring, early summer and late summer, and stop by early fall. Citrus needs more nitrogen than phosphorus or potassium.

Common pests include spider mites, whiteflies and scale. Brown soft scale and two-spotted spider mite are the most common pests in the Midwest. Sooty mold can grow on the honeydew left by sap-feeding insects. Root rot is the most serious disease and is more likely in poorly drained soil. If yellow leaves have green veins, the soil may be not acidic enough, or the plant may need iron.

Fruit on indoor trees often takes 6 to 9 months to fully mature and ripen. Be patient, because a young citrus plant may not bear fruit until after a few years of growth. Potted plants often set more fruit than they can carry, and dropping fruit is normal. Indoor plants may need hand pollination with a small brush.