Question: We keep our home quite cool at night, about 55f degrees. Will this be too cold for our African violets?
Answer: It won’t be too cold, but they won’t be very happy about it. Most varieties currently being grown prefer temperatures somewhere between 60f and 80f degrees–much the same as we do. Violets will survive in temperatures a bit outside of this range, but their growth will be adversely affected. Just like people or machines, they won’t function as well when too cold or too hot. When temperatures begin to fall much below 60f degrees, growth will be very slow, almost seeming to stop. Foliage will become more hairy and center growth will become smaller and bunched, behaving much like a person bundled up at a bus stop in winter. In extreme cases, one might mistake the tight, hairy, centers for a cyclamen mite infestation.
Foliage will be thicker and more brittle. Varieties with variegated leaves will become more heavily variegated, sometimes becoming nearly totally white. The blooms that may still be produced will be larger and more colorful, but will be less numerous and infrequent. If too cold, the blooms may be damaged or discolored, looking like they’ve been “bruised”. When it’s cold, it’s more important to keep excess moisture off of the foliage and blossoms, too.
Having said this, some varieties, and many of the species especially, will be quite happy with cooler than normal temperatures. Some of the species, in fact, won’t do well if it’s not cool. S. goetzeana is one that’s been known to bloom only if it’s kept quite cool. We like to grow our showplants a bit on the cool side, with temperatures between 60f and 70f, if possible, since this promotes better variegation, and larger, more colorful, and longer lasting blooms. Growth is slower, but prettier.