Characteristics of a typical African violet are that it is a tropical, herbaceous perennial. They are put into four different size categories based on diameter. Miniature has a diameter of 6-8 inches or less, semi-mini is 6-8 inches, standard is 8-16 inches, and large is 16+ inches. These plants like partial sun and cannot withstand direct light as it leads to stunted, bleached, and even burned foliage or flowers. Temperature is another critical aspect of caring for these plants as day temperatures above 85 degrees Fahrenheit result in poor growth and night temperatures below 60 degrees Fahrenheit nearly stop growth. Day temperatures between 75 and 80 degrees F are best for growth along with 68-70 degrees F night temperatures. Temperature is also critical to production settings as it can be used to control when the plants will bloom (“African Violet Care”, 2016).

 Any medium used for growing African violets should have good aeration, drainage, and organic matter content because they have fine roots. In the wild, they often grow near sources of water or moisture because their root systems are shallow. The growing medium should be kept moist to prevent desiccation because wilting may result in permanently stunted growth. Relative humidity should be in the range of  50-70%.

There are many diseases that can affect African Violets. They include bacterial blight, botrytis blight, foliar nematode, phytophthora crown rot, powdery mildew, pythium root rot, rhizoctonia crown rot, and ring spot. Bacterial blight shows up as dark reddish brown to black rotting areas on the roots and crown. Infected petioles have a greasy appearance. This can be avoided by not taking infected cuttings, avoiding high temperature and humidity conditions, and keeping new plants separate from old plants. Botrytis blight appears as small, water-soaked lesions on damages petioles and then they spread to leaf blades and infected flowers fade prematurely. This can be prevented by spacing plants and providing proper ventilation, removing fading flowers and yellowing leaves, and applying fungicides to protect healthy tissue. Foliar nematodes appear as small, tan sunken areas on the lower surfaces of leaves. These spots become dry and dull black as they grow larger and plant growth is stunted. Infected plants must be destroyed. Water plants so that the leaves stay dry and no water splashes from plant to plant. Phytophthora crown rot is dark and water-soaked in appearance. It spreads to the petioles and leaf blades and leaves remain firmly attached as the plant collapses. This can be prevented by not propagating infected plants and applying fungicides to healthy tissue. Powdery mildew is a white, mealy fungal growth on the leaves and flowers and it causes them to dry out and die. This can only be prevented by applying fungicide to healthy tissue. Pythium root rot turns roots a dark brown color and plants become wilted and yellow. Do not propagate infected plants and apply a fungicide to protect healthy tissue. Rhizoctonia crown rot causes plants to wilt, collapse, blacken, and die. Reddening of infected tissue may occur at the soil line and leaves readily detach from collapsing plants. You must destroy infected plants and apply a fungicide to protect healthy tissue. Ring spot causes a bright yellow or bleach ring to form on dark green leaves. This can be prevented by keeping irrigation water off of the foliage and using water that is room temperature (“African Violet Diseases”, 2016).

 

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