Winter is the best time to increase Vitamin C intake and that means citrus. Whether you're eating citrus shipped from warmer climates or lucky enough to live in a climate where you can grow citrus yourself, now is the time to enjoy these luscious fruits.
Oranges and grapefruits get most of the citrus attention, but lemons and limes shouldn't be ignored. They're an easy to grow citrus that's perfectly suited to a small space edible garden. Lemons and limes can be grown in the ground in warm climates or in large containers in warm or cool climates. Even gardeners in cold winter areas can enjoy these evergreen trees if they have a sunny space in which to winter them over indoors.
You can select trees that will produce an abundance of fruits for years without needing a pollinator. I remember visiting friends in California and being amazed at how the lemon and lime fruits were so abundant on the trees that many fell to the ground and rotted before they could be eaten.
So plan on growing a lemon or lime outdoors if you live in a USDA zone 9 or warmer climate. In colder areas plant one in a container to bring indoors. Even if you don't have the perfect spot for it in winter and it doesn't fruit, chances are it will at least flower, and the scent will perfume the whole house.
Lemons and limes love plenty of sunshine and moist, well-drained soil. They don't grow well in heavy clay soils or in any location where their roots will sit in water. In marginally hardy areas, consider planting lemon and lime trees against a south-facing wall, building, or fence to create a micro-climate to protect them from cold winter weather.
Plant lemon and lime trees in spring once the weather warms. Although lemons and limes are known for their acidic fruits, the plant itself actually likes a more neutral pH; sweeten the soil with lime if needed. Amend the soil with compost, and plant trees 15- to 25-feet apart, depending on the variety. Dwarf and bush varieties can be planted 8- to 12-feet apart.
For container growing, select a large (15 gallon or half whiskey barrel size) pot, making sure it has drainage holes in the bottom. Fill the pot with moistened potting soil. Keep the container well watered.
The key to developing a healthy lemon or lime tree is watering. Although lemons and limes don't like wet soil, they do require a constant supply of moisture to grow their best. Keep soils moist with drip irrigation or soaker hoses, and mulch. Fertilize in-ground trees 2 to 3 times from spring until summer with a citrus fertilizer. Container trees require monthly fertilization until midsummer.
Prune out suckers that develop along the tree trunk anytime, and thin any spindly branches in late winter after the main fruit harvest. Especially with lemons, prune to create strong scaffold structure of branches that can hold up the heavy fruits. Thin lemon and lime fruits to about 4- to 6-inches apart when they're small if you want fewer, but larger fruits to eat.
Watch out for pests such as aphids and scale on lemon and lime leaves. Aphids love to attack new growth. Spray them with insecticidal soap. Scale insects can be found on the underside of leaves, where their feeding creates a sticky, honeydew secretion that supports the growth of sooty mold. Spray horticultural oil to control scale insects.
In areas with frost like NY, bring container-grown lemons and limes indoors when outdoor temperatures drop to 40 F. Keep trees in a sunny window, reduce watering, and watch for pests.
Our lemon and lime trees should start producing fruit when they are about three years old. Most fruits mature about four months after blooming. Pick lemons when the skin color is completely yellow, but before the skin wrinkles. Wrinkly skin is a sign the fruits are over-mature.
Limes are actually picked when they're still immature and green for best flavor. If allowed to ripen, lime fruits turn yellow like lemons. Harvest about three to four months after flowering when the lime skins have a light green color, are smooth textured, and slightly soft when squeezed. Cut open a few fruits; if they are juicy inside, it's time to pick.