Growing Beautiful Citrus Fruit

june | july | 2017

With their fragrant flowers, rich green foliage, and delicious fruit, citrus are among the most rewarding trees to grow. Those living in USDA Hardiness zones 9–11, where temperatures don’t normally drop below 20 degrees Fahrenheit, can grow citrus outdoors year round. In colder regions, the trees should be grown in containers and brought inside for winter. But the warm temperatures of the summer months help sweet citrus thrive. Consider the following tips when embarking on your fruitful venture.

GROWING CITRUS OUTDOORS

Citrus are easy to grow, untroubled by most pests in a home garden environment, and adaptable to a wide range of soil quality. If the soil is heavy clay, water the plants slowly and deeply with drip irrigation laid around the edge of the leaf canopy so the moisture is absorbed into the soil. In loose, sandy soil, water more frequently. Citrus prefer deep, infrequent watering. Ideally the moisture should penetrate down 36 inches. Between watering, the soil should become almost completely dry, as citrus will languish if over-watered.

The key nutrients for healthy citrus are nitrogen, phosphorous, potassium, magnesium, calcium, sulfur, manganese, zinc, copper, iron, boron, and molybdenum. Most California and Arizona soils have all the necessary nutrients, except nitrogen. Have your soil tested and analyzed for citrus requirements, then apply organic fertilizers as needed in spring and summer.

HARVESTING

Once picked, citrus will not continue to ripen. Unfortunately, skin color is not a helpful guide to ripeness. It is cool nights (ideally 40 degrees Fahrenheit) that turn an orange orange; in Thailand, oranges are always green. Many citrus fruits are fully colored months before they are ripe, and some will develop splotches of green skin after ripening. The best way to determine readiness is to taste a fruit from the tree when that variety is known to be ripe. Use pruning shears to pick, leaving a little of the stem attached to the fruit.

SELECTING CITRUS VARIETIES

The best citrus for you depends on where you live and what you want. Talk to your local Cooperative Extension agent for advice on citrus varieties that grow well in your area. Varieties that do well in Florida are different from those that flourish in the West. To take up less space, consider growing dwarf varieties; they mature at about half the size of a standard orchard tree, but produce nearly as much fruit.

GROWING CITRUS INDOORS

Any type of citrus can be grown in a container (for a while). Lawrence London, an expert on biointensive gardening who lives in USDA Zone 7, grows Persian lime, calamondin (a natural cross between sour mandarin and kumquat that’s good for jam-making), and Meyer lemon in pots indoors. He reports that he had an indoor Meyer lemon that produced ninety lemons one year.

Photography provided by ©iStockphoto.com/spooh.

London yields indoor fruit from his citrus trees with well planned (yet simple) care. When his plants arrived in 1-gallon containers, he repotted them into 2-gallon sized pots with drainage holes and set them on a large plastic tray to protect the floor. Ultimately, as the trees grow, they’ll need to be moved up to 15-gallon sized containers or half barrels. He added compost and garden soil to the larger pot, and topped the soil with charcoal lumps from a wood fire. The charcoal raises the soil’s pH, improves air circulation, and increases the soil’s ability to retain water and nutrients. When the plants need a bigger pot, he’ll add commercial potting soil, more crushed wood charcoal, kelp meal, rock phosphate, greensand, and azomite (a crushed mineral, which supports plant growth and vitality).

To prevent overwatering, London waits until the tray under each pot is dry. He fertilizes with compost tea once every four waterings, and when he takes the plants outside in spring, he fertilizes with a small amount of Peruvian bird guano.

You can grow any citrus indoors or out as long as the conditions are right. Because they are sun-lovers, citrus need a spot that gets as much sunlight as possible; try a south-facing window or sunny spot on the patio and prepare for a treat.