Question: Most of my collection of violets at home have very light leaves, almost white. They aren’t variegated, and they were all green-leaved when I first got them.
Answer: A question we were posed by a visitor to our shop. She claimed to be an “experienced” grower and mentioned this more as a curiosity than as a problem. At first, we thought that she was talking about the reappearance of variegation and, given her description, likely heavy crown variegation. We figured that she might have gotten the plants during the summer, when the warm temperatures may have caused the variegation to disappear. With the onset of cooler weather, perhaps the variegation was returning. This wasn’t the case.
After talking some more, we realized that by “white”, she meant that the leaves had lost all of their color–i.e. a nearly complete absence of green (or any other color). This was a serious cultural problem, not a harmless curiosity. Wanting to know what could have gone wrong, we asked her how she cared for her plants. It seemd that her violets were being “starved” to such a degree that they were no longer willing, or able, to produce chlorophyll (the green leaves). Of course, she insisted she was doing everything properly (we knew better). She listed all of the things she did, including regularly feeding all of her plants with an “African violet fertilizer”, in this case “Granny’s Bloomers”. There, of course, was the answer.
We’ve always suggested that growers always use a “balanced” fertilizer, meaning a formula (N-P-K) containing approximately equal amounts of nitrogen (N), phosphorus (P), and potassium (K). For example, we use fertilizers with formulas of 15-16-17 and 17-17-17 on all of our plants, all of the time. It’s not necessary to use “bloom boosting”, high phosphorus formulas, even for blooming plants like African violets. Far, far, more important to good blooming is a good environment (i.e. adequate light, moderate temperatures), and good care (i.e. watering, soil, etc.). A well cared for plant, in a good environment, will bloom. It does not need to be “forced” to bloom. this is even true for “show” plants, where and abundance of bloom is needed. this is spoken from more than 25 years of experience (and hundreds of shows)–we’ve never had to use high phosphorus fertilizers. They’re just not necessary.
“Granny’s Bloomers”, as the name implies is a high phosphorus fertilizer. What’s more, with a 0-6-5 formula, it has NO nitrogen! A fertilizer with this formula should never be used as the primary diet for the plant. Nitrogen is the most important part of your plant’s diet, the basic fuel, lich starches (or carbohydrates) are for people. Without any of it, your plant will eventually starve. In this case, no nitrogen, means no chlorophyll. No chlorophyll means no green in the foliage. This is a perfect, though extreme, illustration of why a balanced diet is so important in growing healthy, blooming violets. Always feed your plants enough nitrogen. If you do use high phosphorus fertilizers, do so sparingly and when needed–never as a sole diet.