July 2004

This house plant has a most unusual name, Exacum (pronounced ex-uh-cum). A half-century ago, the plant couldn’t be found in the United States, but that changed over the past two decades when Exacum crossed the Atlantic into independent nurseries across the nation. What intrigues plant lovers are the miniscule flowers, blue with bright yellow masses in the center. If you do things right, Exacum will flower for you for months. Let’s see how you care for the plant.

First, there are several varieties of Exacum available at the nursery: Blue Champion, White Champion, Royal Blue, and Little Champ. The care program is the same for all, but remember that Exacum is an indoor plant and, like African Violets, it never goes outdoors.

Light. Where you keep the plant depends on the time of year. From Mother’s Day to mid-October, Exacum thrives in medium indirect light. Before Halloween, move the plant into full sun, keeping it there from late fall and through the winter. Even in early spring, the plant needs full sun, but is moved into indirect sunlight as April gives way to May. Optionally for the winter, Exacum will thrive if placed under grow lights.

Temperature. Normal room temperatures suit the plant Exacum does best with daytime temperatures in the upper 70’s, but in the lower 60’s at night. For this reason, set the plant on the floor of the room when you retire to bed for the night. On awakening in the morning, return the plant to its normal place on a table or whatever.

Water. When to water depends on the growth cycle. When the plant is flowering, apply tepid water every two or three days, always in the morning. After flowering, keep the soil barely moist, usually watering every four or five days. When you move the plant into full sun in October, reduce watering so the soil dries out thoroughly (probably watering once every seven to nine days). Winter care is especially critical, so don’t fertilize at that time.