Can I Grow a Hercules Calla Lily in a Pot?

Calla Lilies

• Not true lilies, callas are more closely related to caladium and jack-in-the-pulpit.

  Trumpet-shaped flowers -- actually modified leaves or spathes -- come in white, yellow or pink to purple tones. Each spathe wraps around a yellow finger-like extension, the spadix, where the plant's very tiny true flowers are collected. Leaves are large, deep green and shaped like arrowheads. In some cultivars, leaves are speckled with white or silver.

Hercules Callas

• The white calla native to Africa (Zantedeschia aethiopica) grows so abundantly there it's considered a weed. Some white callas appreciate heat but Hercules likes cooler temperatures. Give it afternoon shade in hot climates. Plants do fine in bright shade and filtered sunlight full-time. When plants are growing, make sure soil is consistently moist. In fall when Hercules emerges from dormancy, fertilize with low-nitrogen fertilizer such as a 5-10-10 variety. Too much nitrogen will turn spathes green. Fertilize again every eight weeks during the growing season.

Potting

• Start with a 1-gallon container. Fill it to within 3 inches of the top with a mix of two parts organically rich, well-drained potting soil to one part perlite, pumice or horticultural sand. Lay the tuber down on the potting soil sideways, and cover it with 2 inches of the potting mix. Don't compress or pack the soil. Water so that soil is thoroughly moist but not wet. Continue to water lightly until new leaves are 4 inches tall. At that point, increase watering, and keep soil moist throughout the growing season.

Repotting

• Hercules callas will need repotting when roots reach the bottom of the container and are visible through the drain holes. "Pot up" to a larger container every time you replant your tuber, burying it 1 to 2 inches deeper than you planted it previously to accommodate its increasing size. Hercules grows rapidly with reasonably good care. Within a few years, you may need a 10-gallon container, which will be challenging to carry into the house for winter. Mature Hercules callas with a 6-inch tuber may require a 30- to 40-gallon pot.