Citrus: Expanding the Boundaries

"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.

"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.

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.