Living with dwarf citrus: watering, feeding, keeping them small
Dwarf citrus plants in pots (see page 94) require a certain amount
of attention to grow and produce well. To formulate guidelines for
outdoor care, some 40 Sunset readers and nursery experts who grow dwarf
citrus in containers shared their experiences with us.
Our readers reported growing 25 different varieties:
“Eureka’ and “Meyer’ lemons led the list, followed
by “Bearss’ lime. One gardener called her 40-year-old
“Ringpur’ lime a “highly rewarding friend’; another
described a 26-year struggle with a dwarf “Valencia’ orange
that finally bears “beautiful crops.’
While different kinds of dwarf citrus vary in hardiness and heat
requirements, care is similar. Ideally, they should have a sunny,
wind-free southern exposure. Rub out any suckers that appear below the
graft union; after fruiting, prune for tree shape and desired height.
Basic container care. Some kinds of citrus plants, especially
navel oranges and lemons, have large root systems that demand a
commodious container. For transplanting a 5-gallon-size plant, an
18-inch-diameter or larger container should be ample for several years.
Half whiskey barrels are ideal; redwood tubs or large clay, ceramic, and
plastic pots are suitable –as long as they allow good drainage. (You
may need to drill drain holes.)
Other varieties, such as calamondin and “Chinotto’ sour
orange, grow happily for years in 8- to 10-inch containers.
From time to time, you may need to add some planting mix to
replenish lost soil and keep roots covered.
About every two to four years, repot plants in fresh soil mix or
transplant them to a larger container if needed (one sign is roots
poking through drain holes).
When replanting, use a standard container mix. Make sure the graft
union is as far above the soil level as it was in the original
To repot in the same container, you’ll need to prune the
plant’s roots. Use
a clean, sharp knife or pruning saw to cut the outer 1 to 2 inches
off sides and bottom of the root mass. Spread an inch or two of fresh
soil mix in the bottom of the container and replace the plant, then fill
around the root mass with more mix. Water well, and add more mix if
Watering. With porous, fast-draining potting mixes, it’s hard
to overwater. Lack of water quickly stresses citrus plants, causing
leaf, blossom, or fruit drop–even plant death.
In normal winter weather, containergrown citrus need watering about
once a week. In summer hot spells or windy weather, plants may need
water every day. (Note: different watering rules apply to citrus
planted in the ground.)
Experienced gardeners rig drip-irrigation systems, running
spaghetti tubing from hoses to containers, where spitter-type emitters
spray water over the root zone. (Regular drip emitters can, over time,
cut channels down through container soils, bypassing much of the root
However you irrigate, do it consistently and deeply so a small
amount of water trickles out the drain holes.
Feeding. Frequent watering leaches nutrients at a faster rate.
Some successful growers feed container citrus year-round; others feed
their plants from late winter to October.
Use a high-nitrogen fertilizer with an NPK ratio of about 3-1-1.
You’ll find fertilizers sold in several froms: liquids and
water-soluble crystals for monthly or more frequent feeding, and
controlled-release fertilizers for less frequent application. Follow
Citrus also need periodic feeding with micronutrients–especially
iron, zinc, and manganese–to keep them green and healthy looking.
Plants lacking iron develop chlorosis: yellowing leaves with dark green
veins. Zinc deficiency shows up as yellow mottling between leaf veins.
Symptoms of manganese deficiency are similar to those of zinc. Traces
of these elements, often combined, are sold in chelated forms for soil
and foliar application.
Controlling pests. Creatures that sometimes bother citrus include
aphids, mealybugs, mites, scale, and snails.
If snails are a problem, control the ones you see by hand-picking;
lay chemical bait for the sneakier ones.
Hosing foliage frequently helps discourage insect pests; jets of
water can blast off minor infestations. If insects get out of hand,
spray with an insecticidal soap or a dilute solution of a mild liquid
dishwashing soap (about 2 tablespoons per gallon of water). As a last
resort, treat with a specific chemical pesticide.
Cold-weather protection. When a cold snap threatens, container
portability really counts. If a heavy frost is predicted, move citrus
plants under an eave. If a freeze warning or temperature below 26| is
forecast, the safest way to protect citrus plants is to move them
temporarily into a warm garage or indoors.