Question: I just bought some violets and need some idea how to care for them. If I happen to overwater them, do I just need to drain the water from the bottom? Some of the leaves look almost black and I am afraid of killing it.
Answer: Yes. I assume this means discarding the unused water in the saucer. It’s best not to leave plants sitting in water, unless the soil mix being used is very light and porous. Again, the rule of thumb is, the wetter you plan on keeping the plant, the lighter the soil mix should be. One reason why light, soilless, mixes are so often recommended is because they allow the grower to occasionally overwater without doing much harm to the plant.
What concerns us is your saying that the leaves look “almost black”. Soft, “mushy”, black leaves are a symptom of overwatering. Remember that leaves can appear soft and wilted, yet the plant may not need watering. If the plant has a wilted look, yet still has moist soil, don’t water it. Instead, observe it for another day or two and see if its condition improves. If it doesn’t, or leaves begin to turn black and rot off, the problem is more serious. If the soil is very wet, remove the plant from its pot and lay it on some newspaper to let it dry. Remove the rotted leaves, since these likely won’t recover. As the soil begins to dry, the remaining foliage should become more firm and fresher looking. At this point, repot the plant into fresh soil, being sure to use a pot no larger than the root system itself. After repotting, water more sparingly than normal, until new roots have grown into the added soil.
The old “dry to the touch” rule is worth remembering. Ideally, violets would like to be slightly moist at all times. This means watering when the surface of the soil is dry, and not before. Here at our shop, when we teach someone new how to water our plants, we tell them to thoroughly water all plants where the surface of the soil is dry, sparingly water those whose soil surface is slightly moist, and not water at all those whose soil is still damp. If a light enough soil mix is being used, most plants can survive an occasional unnecessary watering, but won’t survive when this is done two or three times consecutively.