Plant growth and color often indicate need for fertilizer. A gradual loss in leaf color combined with a reduced growth rate usually indicates that fertilizer is needed. If in doubt as to whether plants need additional nutrients, fertilize one or two and wait about 10 days to see how they react. If plant growth is evident and they become darker in color, the rest of the plants may be fertilized. African violets may be propagated easily by leaf cutting, and about 6 to 9 months are required to obtain flowering plants.
Any leaf is satisfactory if healthy and firm.
A combination of half vermiculite and half sand, by volume, makes an ideal propagating medium or the soil used for growing plants may be used. Insert the petiole into the medium by pushing it into a hole made with a pencil or similar tool. Roots normally appear at the petiole base in 3 to 4 weeks under good conditions and leaves of the new plants appear at the medium surface 3 to 4 weeks after root formation. Old multiple-crown plants may often be successfully propagated by division. Carefully cut each crown away from the plant so that each plant has its portion of the root system.