For the most part, the areas where home gardeners plant the citrus trees are the same areas where citrus is
grown commercially. But if space is limited or climate isn't suitable,
it's still possible to enjoy these trees and their bounty year-round.
How? By growing citrus trees in containers.
If you live in the mild-winter West, Southwest, or Southeast, you can
grow most kinds of citrus in container outdoors year-round. Where
winter minimum temperatures regularly dip below 25° F, you can still
grow citrus trees if you have a bright spot indoors or out protected
Which Types to Grow?. Any type of citrus tree can grow in a container, at least for a while. However, kinds such as lemon and
grapefruit, which naturally grow into larger plants, will quickly
outgrow their containers.
Generally your best are the naturally small varieties such as 'Improved Meyer' lemon, 'Bearss' lime, 'Satsuma' mandarin, and kumquat.
These varieties are more likely to remain both healthy and productive
in containers for several years.
Or choose any citrus that is grafted to Flying Dragon (Hiryu) rootstock. Any citrus growing on this rootstock will be significantly dwarfed, thereby extending its useful life in a container.
Size and Type of Container. Choose a pot about the size of a 15-gallon nursery container. The ubiquitous half whiskey barrel is a
good size, too. In traditional European orangeries, the classic
container is 24 inches square and deep, and painted white. Plastic and
faux clay pots in the 30- to 36-inch-diameter range work well, but
plastic will transmit the sun's heat more readily than wood or clay,
perhaps enough to damage roots. Wooden containers are prone to decay.
You can significantly slow the decay process by coating the interior
with asphalt roof patch.
Whatever kind of container you choose, make sure it has good drainage; drill extra holes if you're in doubt. To prevent soil from
washing out, cover drain holes with small sections of window screen,
but don't cover the holes with stones. To facilitate drainage and allow
good air circulation around the container, raise it slightly off the
Soils. Use a premixed sterile potting soil designed for container plants. Never use ordinary garden soil even good soil for
container citrus. What is just fine in the ground just won't work in a
container. Once confined in a container, most garden soils are too
dense and water drains too slowly. Though you can make your own soil
mix (4 parts ground pine or fir bark and 1 part fine sand), unless you
need a lot it's more cost effective to buy it ready-made.
Watering and Fertilizing. Plants in containers generally require more frequent watering than the same plants in open soil, and
citrus are no exception. Especially during hot, dry, or windy weather,
daily watering may be necessary. The basic rule is to soak the rootball
thoroughly until water drains out the bottom once the top 2 to 3 inches
of soil are dry.
In some situations, water will drain out the bottom of the pot without soaking the rootball. This happens when the rootball dries and
shrinks slightly, pulling away from the edges of the container. The
water moves down the gap without rewetting the roots. To help rewet the
dried rootball, place three or four drops of a mild dish soap on it.
The soap will help the water soak in so the rootball can expand to fill
the container again.
Frequent watering causes needed nutrients to wash through the soil more quickly than is typical in most soils. Controlled-release
fertilizers are less apt to immediately wash through soil, making a
single applications useful for a longer time. (Exactly how long depends
upon the specific fertilizer and your watering frequency.) Soluble
liquid fertilizers generally provide more exacting control but also
require more frequent applications, every other week or so. In either
case, follow the directions on the label of the fertilizer you choose.
More than most plants, citrus are prone to deficiencies of the micronutrients iron, manganese, and zinc. Inadequate amounts of any one
of them will cause leaves to yellow while veins remain green. Therefore
it is a good idea to apply these to citrus in containers at least once
a year. Look for them in the "chelated" form which makes the
micronutrients more accessible to citrus roots. The best time is in
early spring just as new leaves are beginning to emerge.
Growing Citrus Indoors. By moving container-grown citrus into a greenhouse, sunroom, or bright indoor location, gardeners anywhere
can grow them. Most of the same rules apply, with a few differences.
First, if you hope to harvest fruit, choose a naturally acidic citrus, not a sweet orange or grapefruit. Examples of acidic varieties
include 'Improved Meyer' and 'Ponderosa' lemons, calamondins, and
kumquats. These are most likely to produce fruit indoors in winter.
Other citrus will grow and flower but are less likely to produce fruit.
When moving your plants outdoors in spring or back indoors in fall, make the transition gradual, in at night, out during day, and
lasting about a month. Also, before moving the plant indoors, shower it
completely with warm and slightly soapy water to wash off any bugs.
Pests that you don't notice outdoors can become problems once inside.
Compared to outdoors, homes in winter are darker and warmer, and have much drier air. That's why anything you can do to provide
additional light and extra humidity is so beneficial: grow lights, and
a tray of pebbles under the pot. Cool, bright rooms, such as a
partially heated sunroom, are best.
Naturally acidic citrus, such as 'Improved Meyer' lemon, are best for indoor growing.
Supply nutrients with controlled-release fertilizers to reduce the number of applications necessary through the year.
Rewet dry citrus rootballs by placing a few drops of mild dishwashing
soap directly onto the soil, then water with slightly warm water.
I have a clementine growing that is slowly getting bigger. I need to give it more aspirin water/ one 325 per gallon. And I want to try braiding three apple tree whips of three different varieties together and seeing how they do.