There are a couple of things that can keep your clivia from blooming.

Correct light conditions are essential for producing flowers. Bright light in the early morning or late afternoon is best, with protection from the strongest mid-afternoon sunlight which will scorch the leaves. Without adequate sunlight, your plant will not bloom.

Your clivia also needs to have a winter rest to gain the strength it needs to bloom. During the growing period it does well in a warm room but in early winter it needs to spend 6 to 8 weeks at a temperature of about 45 to 50 degrees. Gradually reduce the water that your plant gets during the fall so that you are keeping it nearly dry over the rest period. You can begin to increase water and temperature as you see flower stalks emerge.

Finally, your plant likes to be pot bound. Topdress it with fresh soil annually and change pots only when roots completely fill up the pot, every 4 years or so.

Courtesy of NYBG Plant Information Service