Living with dwarf citrus: watering, feeding, keeping them small Dwarf citrus plants in pots (see page 94) require a certain amountof attention to grow and produce well. To formulate guidelines foroutdoor care, some 40 Sunset readers and nursery experts who grow dwarfcitrus in containers shared their experiences with us. Our readers reported growing 25 different varieties:”Eureka’ and “Meyer’ lemons led the list, followedby “Bearss’ lime. One gardener called her 40-year-old”Ringpur’ lime a “highly rewarding friend’; anotherdescribed a 26-year struggle with a dwarf “Valencia’ orangethat finally bears “beautiful crops.’ While different kinds of dwarf citrus vary in hardiness and heatrequirements, care is similar.
Ideally, they should have a sunny,wind-free southern exposure. Rub out any suckers that appear below thegraft union; after fruiting, prune for tree shape and desired height. Basic container care. Some kinds of citrus plants, especiallynavel oranges and lemons, have large root systems that demand acommodious container. For transplanting a 5-gallon-size plant, an18-inch-diameter or larger container should be ample for several years.Half whiskey barrels are ideal; redwood tubs or large clay, ceramic, andplastic pots are suitable –as long as they allow good drainage.
(Youmay need to drill drain holes.) Other varieties, such as calamondin and “Chinotto’ sourorange, grow happily for years in 8- to 10-inch containers. From time to time, you may need to add some planting mix toreplenish lost soil and keep roots covered. About every two to four years, repot plants in fresh soil mix ortransplant them to a larger container if needed (one sign is rootspoking through drain holes). When replanting, use a standard container mix. Make sure the graftunion is as far above the soil level as it was in the originalcontainer. To repot in the same container, you’ll need to prune theplant’s roots. Usea clean, sharp knife or pruning saw to cut the outer 1 to 2 inchesoff sides and bottom of the root mass.
Spread an inch or two of freshsoil mix in the bottom of the container and replace the plant, then fillaround the root mass with more mix. Water well, and add more mix ifneeded. Watering. With porous, fast-draining potting mixes, it’s hardto overwater.
Lack of water quickly stresses citrus plants, causingleaf, blossom, or fruit drop–even plant death. In normal winter weather, containergrown citrus need watering aboutonce a week. In summer hot spells or windy weather, plants may needwater every day. (Note: different watering rules apply to citrusplanted in the ground.) Experienced gardeners rig drip-irrigation systems, runningspaghetti tubing from hoses to containers, where spitter-type emittersspray water over the root zone. (Regular drip emitters can, over time,cut channels down through container soils, bypassing much of the rootsystem.) However you irrigate, do it consistently and deeply so a smallamount 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 feedtheir 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 andwater-soluble crystals for monthly or more frequent feeding, andcontrolled-release fertilizers for less frequent application. Followlabel instructions. Citrus also need periodic feeding with micronutrients–especiallyiron, zinc, and manganese–to keep them green and healthy looking.Plants lacking iron develop chlorosis: yellowing leaves with dark greenveins. Zinc deficiency shows up as yellow mottling between leaf veins.
Symptoms of manganese deficiency are similar to those of zinc. Tracesof these elements, often combined, are sold in chelated forms for soiland foliar application. Controlling pests. Creatures that sometimes bother citrus includeaphids, 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 ofwater can blast off minor infestations.
If insects get out of hand,spray with an insecticidal soap or a dilute solution of a mild liquiddishwashing soap (about 2 tablespoons per gallon of water). As a lastresort, treat with a specific chemical pesticide. Cold-weather protection. When a cold snap threatens, containerportability really counts. If a heavy frost is predicted, move citrusplants under an eave.
If a freeze warning or temperature below 26| isforecast, the safest way to protect citrus plants is to move themtemporarily into a warm garage or indoors.