Growing Organic Citrus
Every home should have at least one citrus tree in the garden, where suited to the climate, to provide delicious fruits packed with vitamin C. Few things beat a freshly picked juicy tangerine just off the tree, or squeezing a little fresh lemon juice on your organic salad. Citrus trees have shiny evergreen leaves, fragrant flowers, and attractive fruits that hang for months without dropping. In northern climates, you can grow dwarf citrus trees in containers and bring them indoors during the winter.
There are so many types of citrus that you may have trouble deciding which to grow. Edible types include grapefruit, lemon, lime, kumquat, mandarin orange, tangerine, orange, tangelo, and temple orange.
Consider the yearly range of temperatures and possible frost, when making your selection. Local nurseries usually stock citrus that grow well in the area. The fruit of all types is easily damaged by frost, but the leaves and wood of some are more cold-resistant. In general, limes are the least hardy, oranges slightly hardier; kumquats are the most hardy, withstanding low winter frost temperatures.
A single mature citrus tree yields more than enough fruit for a family. If you plant more than one tree of the same type, select cultivars with different harvest times, or plant different types of citrus so you won’t be overwhelmed with one kind of fruit. Almost all citrus are self-pollinating. A few hybrids are not; be sure to check for the kind you want when you buy.
Select sturdy nursery-raised trees. A one-year-old tree should have a trunk diameter of ¾ inch. A two-year-old plant should have a diameter of at least 1 inch. Those with fewer fruits and flowers are better because they have put more energy into sturdy top and root growth.
Most commercially grown citrus fruits are grafted onto rootstocks that are resistant to frost and insect attack. Select the proper citrus for your area when your soil is susceptible to nematode attack and other soil problems. Your local extension office or a good quality nursery could tell you what rootstock is best in your region.
Citrus do best at pH 6.0-6.5. They are not fussy about soil but do require good drainage. If drainage is a problem, plant trees in a raised soil mound, about 1½ feet high.
Select a sheltered area with full sun, such as a sheltered, south-facing alcove of a building. Citrus flowers attract bees, so don’t plant them in high-traffic areas.
It is best to plant citrus in late winter or early spring. Keep the graft union six inches above soil surface when planting. Full-sized trees require at least 25 feet between trees; smaller trees need less.
Citrus bark is thin and easily sunburned. Wrap the trunk with commercial tree wrap or newspaper for the first year, or paint it with diluted white latex paint.
In dry areas, water newly planted trees at least once a week for the first year. Once established, trees need less-frequent watering, but never wait until leaves wilt to water. Water stress can cause developing fruit to drop; prolonged drought causes leaf drop and may kill the tree. Water slowly and deeply; shallow sprinkling does more harm than good. In drought areas, construct a shallow watering basin that extends from six inches away from the trunk to one foot beyond the drip line. Or install drip irrigation under a thick layer of mulch to conserve water and protect shallow feeder roots. Keep mulch six inches away from the trunk.
In citrus-growing areas, soils often lack organic matter and nitrogen. Spread compost, mulch and Dr. Earth® Fruit Tree Fertilizer on the soil surface out to the drip line four times a year, beginning in February. This will help to ensure a healthy productive crop that will be full of nutrition for you and your family.
Most citrus trees need little pruning beyond removing dead or broken branches. Limit the tree’s size by thinning out fast growing shoots that outgrow other branches. Thin the branches, rather than shortening them. Remove suckers as soon as they emerge from the ground.
You can revitalize an old unproductive citrus tree by pruning severely in early spring. Wear thick gloves if the tree has thorns. Cut off all branches two inches or larger in diameter flush to the trunk, and feed and water heavily for the next year. Note: Very severe pruning may stop fruiting for up to two years.
Citrus are usually grown outdoors in climates where frost is rare. Some types of citrus fruit are vulnerable when frost does occur. In areas where mild frost is common, don’t plant cultivars that bear in winter and early spring. Since succulent new growth is more prone to frost injury, withhold extra water in late summer to limit new growth. When frost does threaten, cover trees with large fabric sheets. Use fans to keep air circulating around the trees. If symptoms of frost damage appear, wait until spring growth starts to see the true extent of damage. A tree that loses all its leaves can still rejuvenate. If damage is severe, dieback may continue during the growing season.
Citrus trees usually bear in three to four years. It can be hard to tell when citrus fruit is ready to pick. Color is not a good indicator. Fruit can have ripe coloration several months before being ready to harvest or remain green and unappealing even when ripe and juicy inside. Use the taste test to determine when fruit is at its peak flavor. Allow fruit to ripen on the tree before picking.
Use pruning shears to cut stems close to the fruit when harvesting. Don’t just pull fruit off the tree. Ripe citrus fruit can remain on the tree for up to three months. Once harvested, citrus can be stored in the refrigerator for three more weeks. Enjoy the fruits of your labor; they will be juicy and full of flavor and nutrition.
Milo Lou Shammas
Founder and Formulator