Dwarf Citrus Trees: Big On Flavor & Fragrance

During the cold, gray days of winter, few things brighten and warm a room like the sweet, rich aroma of lemon blossoms or the glow of maturing oranges among glossy, green leaves. Thanks to the widespread cultivation of dwarf citrus trees, any gardener with a bright window can enjoy all the sensory pleasures of lemons, limes, oranges, and more, all year long.

Like most fruit tree cultivation, where a branch or scion of a desirable variety of tree is grafted onto a sturdy rootstock, dwarf citrus trees are grafts of a normal fruit-bearing branch onto dwarf rootstock, which keeps the plant at a manageable size for summer patios and year-round enjoyment in your solarium.

Because the fruiting branch is from a full-sized tree, the fruits which develop are also full-size, and full-flavored. However, that also means that like a dutiful orchard manager, you will have to prune your tree periodically to keep it within bounds. Normally, pinching off growing tips will help maintain an attractive shape, which is preferable to letting the plant send out tall shoots requiring severe pruning.

In addition, always remove shoots or “suckers” which tend to pop out from the dwarf rootstock. Look for a diagonal scar running the trunk’s circumference around about six inches above the soil surface. Snip off any shoots below the graft union as those pesky shoots will sap energy from the desired plant, and produce, if at all, inconsequential or tasteless fruits.

The majority of dwarf citrus used as container or houseplants tend to grow between four and six feet tall, and do best in pots ranging from 12 to 16 inches in diameter, although some popular cultivars can be grown in containers as small as eight inches.

In milder climates, dwarf trees can reach up to nine to 12 feet when grown in halved whiskey barrels or redwood tubs. Around here, though, citrus must be taken indoors before any danger of frost, and most of us would rather not lug a several hundred pound giant into a standard family room.

To keep your dwarf citrus in check, you will actually borrow some techniques from the world of bonsai. Root pruning is usually required every three years or so, which will control overall growth, while also allowing you to replenish soil and soil nutrients. Without root pruning, you will have to continually repot your specimen until it becomes a behemoth.

To begin, carefully remove the plant from its pot and use a sharp knife or pruning shears (or even a pruning saw) to trim off several inches of root from around the sides and bottom of the root ball. Use a standard container soil mix to replace and reposition the plant at its previous height in the pot.

Incidentally, root pruning is often traumatic for many novices, who are more comfortable with watering and feeding their plants. But fear not, eventually everyone gets used to it, and your tree will continue to thrive and flourish for many years, possibly even dozens or more.

Ongoing care for your dwarf citrus requires plenty of bright light and even exposure. Be sure to slowly rotate containers every week or so. After all, no one likes a lopsided lemon tree.

Dwarf citrus prefer evenly moist soil. Do not allow the soil to completely dry out, and do not waterlog the soil or allow the plant to sit in standing water. Many practitioners consider an inexpensive moisture meter indispensable and as important as a good pair of pruning shears. Plan to water a bit more frequently than you might with other houseplants, perhaps every three to four days, especially during warm, dry weather.

Note that citrus are heavy feeders, especially as frequent watering will leach out water-soluble nutrients like nitrogen. It is recommended to use a fertilizer with a ratios two to three times higher in nitrogen than potassium and phosphorous (an N-P-K of 3-1-1). Be sure to use a complete fertilizer periodically to replenish essential micronutrients.

Of course, the most important element in dwarf citrus cultivation is selecting a plant that will intoxicate you with its fragrance and tickle your taste buds.

The choices are delicious in their own right, ranging from typical naval oranges, tangerines, lemons, true limes and grapefruits, to a host of hybrids with special characteristics. For the most part, growers have selected varieties specifically for container and indoor use which will do well in relatively cool environments. You do not have to replicate Floridian heat to achieve sweet and luscious fruit.

Among oranges, some of the most readily available and favored are Trovita, with a thin skin, which is equally prized for juice or eating. Satsuma oranges, sometimes considered a mandarine, like Valencia, are smaller, with an easy-to-peel fruit and a truly intoxicating aroma from spring-borne blooms which last up to a full month.

And while oranges might be the first citrus variety you are considering, spare a thought for the lemon tree. While most citrus bloom in the spring and produce fruit the following winter (or later), lemons actually bloom throughout the year, providing four seasons of fragrance, and year-round fruit. The most popular varieties include Lisbon, Eureka and Meyer, the latter of which is thought to be a cross between a sour orange and a lemon, and is perhaps the most popular variety of all thanks to its somewhat sweeter, slightly tangerine flavor.

Limes aren’t only for margaritas and gin-and-tonics! In addition to favorites like Bearss Seedless, one of the most intriguing offerings is Kaffir (or Thai) lime. In addition to tangy juice and a zesty zest, the glossy, dark green leaves of this variety can be chopped or julienned and used much like lemon-grass in Thai and other related Indonesian cuisine.

And while grapefruit are available, why not explore the exciting world of hybrids. For example, consider the increasingly popular Minneola Tangelos, or Honeybell, a cross between tangerines and grapefruit. This juicy, bell-shaped find offers a bright, reddish-orange skin, easily peeled like its tangerine ancestor, and sharing both a tartness and intense tangerine flavor.

Clearly, while these varied citrus trees may be dwarf in size, the selection, flavors, fragrance, and rewards of raising them are truly enormous.

Copyright 2010, Joseph M. Keyser