African violets can bloom any time of the year. They are indoor plants, and as such, are not under the constraints that other plants are to bloom seasonally.
Some growers say their violets actually can bloom 12 months of the year; in other words, all the time. I, myself have found that after blooming for six to eight weeks my violets need to take a "rest" period of one to three months.
But, usually my violets are in bloom twice a year, sometimes three, and at six to eight weeks at a time that sums up to about five to six good months of blooms, not too shabby! They are especially lovely when blooming during the cold of winter, when their deep green foliage and bright colorful blooms are in contrast to the white snow or the gray landscape, outside the window. One thing that will contribute to violets' potential to bloom year-round is to fertilize them every time they are watered. That, along with enough sunlight, humidity and warmth is the best recipe for African violets.
It is not uncommon for violets to "sport". In other words, your white violet puts up a purple blossom, or pink blossom or some other color. When the hybridizer created your particular variety, they cross pollinated two violets, more than likely, one of them was purple. So your violet has reverted back to one of its parents. Will it go completely purple? That's a good possibility. Why? Well some are just more "unstable" than others. I would guess the plant you bought was probably an Optimara violet.
Optimara violets are grown by a huge commercial grower in Nashville, Tenn. It was started by the Holtkamp family when they were in Germany. Eventually they came to this country and the family has carried on with violets for years and years. They are the biggest or at least one of the biggest commercial violet hybridizers and growers in the nation.
They produce plants for the home grower that uses window light. Folks like me that have ten lighted plant stands and a big room grow for show, I do grow Optimara violets, some of their plants make great show plants. However, when I do get one, I figure it has at least a 50% chance of sporting to a different color.
That makes it not blooming true so I couldn't show it under the name that was given because the plant would not match the description they gave to the African Violet Society of America to register it. Complicated I know but that's the rules and since I'm also an African Violet judge, I have to know those rules.
When a violet sports to a different color, it doesn't mean you have done anything wrong. Although environment can be a factor, it is more likely that the plant is just not stable. Sometimes you get pretty interesting color combinations from the plant that sports. Sometimes it will change colors and never go back to the original color. In fact, all the plants that I have grown that sported never went back to the original color. You never know what you'll wind up with sometimes.
