Citrus: Expanding the Boundaries

You don't have to live in California or Florida to grow great citrus. And you don't have to limit yourself to the usual orange or lime.

"What stops most people from growing sumptuous citrus is a climate that doesn't get hot enough and lack of space," says master gardener Paul James. "Two problems, one solution — containers!"

Heat-loving citrus growing in containers can go from sunbathing in the backyard during summer to a protected south-facing porch in the winter. But what you plant can be as important as where you plant. Lemons and limes are generally less tolerant of cold than oranges and kumquats.

Limequats

Tangelo

Blood oranges

Citron

"Most varieties will take 25 or 26 degrees for short durations," says nurseryman Tom Spellman. "There are other varieties that will take some extremes: satsuma mandarins or 'Nagami' kumquats can go down to 15 degrees before they freeze."

Citrus trees are heavy feeders. "They're really busy," Spellman says. "They're evergreen, they're flowering, they're producing massive quantities of fruit, so they're using up lots of nutrients." Feed them four to six times a year. Spellman recommends a balanced, organic fertilizer, something with lots of trace minerals. Apply it lightly, then rake it in. Add a layer of mulch.

Your tree may produce scores of unwanted suckers. "This is an example of a citrus rootstock gone wild," Spellman says. "It's growth that's coming from the bud union and it needs to be removed for the tree to maintain its health." The bud union is where the lemon was budded onto the rootstock to help it grow vigorously. Remove everything below that point to channel the energy into producing healthier, sweeter, better-quality fruit.

Potted citrus can be espaliered. For this display, Spellman used a standard 3' x 3' trellis planted behind a variegated pink lemon tree. He created a two-dimensional fan shape by gently tying branches to the trellis using stretchy garden tape. The more space he fills, the more fruit he'll harvest, but with espalier, thin is in.

As the little tree grows, tie up the long growth spurts to the trellis. Prune off anything that grows out of shape or off the structure.