Amaryllis collects nutrients via its foliage to replenish the bulb after it completes its first blooming cycle. Removing the leaves prematurely prevents the amaryllis from collecting these nutrients, which can cause the bulb to produce foliage but no flowers the following year. After an amaryllis completes flowering, leave the foliage in place. Continue to water the plant and provide it with plenty of sunlight over the summer months, allowing the leaves to gather plenty of nutrients.
A dormant period is necessary for amaryllis to bloom. Reduce watering in fall until the foliage dies off naturally. Store the amaryllis in dry soil in a dark area for 8 to 10 weeks, then resume watering and provide light to encourage new growth. If a dormancy doesn't occur or is interrupted early, the amaryllis produces foliage but won't form a flower stalk. The rest period is vital for flowering.
Several diseases can inhibit flowering in the amaryllis. Mosaic virus causes yellow discoloration on the foliage and eventually inhibits flower bud formation. Fungal infections also affect the bulb's ability to bloom, as they often cause the bulb to rot and weaken. Amaryllis may show brown spots or other discolorations on the foliage.
Overwatering leads to bulb rot. The bulb may produce some foliage before it weakens completely, but usually fails to flower. Amaryllis also need plenty of sunlight to produce flower stalks and bulbs. Avoid placing them in dark rooms or other areas with limited light. While the plants do collect many nutrients from the sun, they also need frequent fertilization, as flower formation expends a lot of energy. Regular application of a balanced houseplant food when the amaryllis is actively growing provides it with the necessary nutrients to form buds.