Exacum, whether indoors on a sunny windowsill or in a partly shaded bed outside, is very easy to grow and needs little care.
This fragrant annual tolerates dusty, dry soil and weeks of record-high temperatures, remaining as happy as the potted exacum which is watered daily. However, the indoor plant, two to a pot, follows weeks earlier and has larger leaves.
Also, the indoor plant is likely to grow in tree form -- at least Blythe Spirit, a white variety, does -- while the same exacum out in a small bed is shrub shaped.
In mid-July, or even before, each potted exacum produces seven separate 5 -petal white flowers with bright yellow stamens over light green centers.
At this time, the annual, which grows to about 8 inches, is almost 6 inches high. These beautiful, fragrant blossoms last from two weeks to a month. By then, all the outdoor exacums are flowering heavily.
You can sow exacum seed, which is very fine, in early spring in a wide clay bulb pot filled with sandy loam or a mixture of half garden loam and half medium sand with the top half inch sifted.
Scattered over the surface and gently pressed into the soil with the flat side of a broken brick, they sprout within two weeks so long as the soil surface does not become dry. However, such minute seeds often must be resowed more than once.
During the first week, a wet brick or a pane of glass can be placed over the bulb pot which should be kept where the temperature is between 65 and 71 degrees F.
For weeks after the sprouted seeds become minuscule seedlings, they can barely be seen. Any weeds, big and visible, are easy to pull.
Where the seedlings are crowded, half-inch cubes of earth and massed seedlings can be lifted and transplanted to any bare spots. For this you need strong daylight and a narrow-blade, slender-tip knife rather than an old stainless-steel table knife which is so handy for transplanting average-size seedlings.
Before the exacums are large enough to transplant in a bed, another thinning will be needed.
Be sure that the roots of any newly transplanted exacums do not become dry. The bed should be soaked three times a week during hot, rainless weather. About twice a month they can be watered with diluted fish fertilizer.
If any of the plants stops growing, loses color, or wilts more than a week after being planted outside, extra water and cultivation should save it.
After an exacum is established, it appears to thrive through both heat and drought even if the sandy loam around it becomes dry.