Gardening Articles: Edibles :: Fruit & Nut Trees
Wild New Citrus (page 5 of 5)
by Lance Walheim
Where to Grow Citrus
Most citrus are native to tropical or semitropical climates. In most cases, both fruit and foliage are damaged if temperatures fall much below freezing for a prolonged period. With few exceptions, citrus grow outdoors in a relatively narrow region that extends from northern California, south into southern California, eastward through the low-elevation deserts of Arizona, into southern Texas, along the Gulf Coast and south through Florida. The exact breadth of this "citrus zone" is delineated by how cold it gets in winter.
However, you can grow citrus in containers anywhere. By planting in containers and growing trees outdoors in summer, you can grow citrus trees in any climate. You won't get the same crops that trees in outdoor soil produce, but you'll harvest some fruit and enjoy the flowers. Any of the varieties I've mentioned above will grow and fruit in containers.
The classic citrus container of European orangeries (frost-free sunrooms for citrus) is a 24-inch-square wooden box, usually ornamental and painted white. Any container of approximately 15-gallon size, such as a half wine or whiskey barrel, works fine. Never fill your container with soil from the garden. Use a premixed potting soil, usually composed of sand, peat moss, fine bark, perlite or vermiculite. I recommend adding a slow-release fertilizer and a water-holding polymer.
Provide the right conditions indoors. Place trees in a cool, bright location and maintain high humidity around them. A cool greenhouse where temperatures stay above freezing is ideal. Don't overwater your trees. Allow the soil surface to dry partially between wateri and use a liquid or soluble fertilizer at label strength and frequency. If trees bloom indoors, hand-pollinate flowers by daubing them with an artist's paintbrush.
Allow for slow, gradual transitions between indoors and outdoors of at least three or four weeks. Before bringing a citrus tree indoors, gradually move it to where it receives less and less direct sunlight. Just before moving the plant indoors, hose it off to clean the leaves. Keep a watchful eye out for insect pests such a aphids, mealybugs and spider mites. If any of these appear, spray the leaves with an insecticidal soap.
Shipping citrus trees to the citrus states or regions -- Arizona, California, Florida and Texas -- is restricted. If you live in one of these regions, buy trees locally.