indoors or outdoors? and how big are the plants - or add a photo if you can please, including showing the pots so we can see what size they are. Thanks.

the buds are laid down in the late summer. So the plant either didn't get enough water in the summer or enough nutrients. if you care for them properly this year you will get more buds next year. how you do this will depend on the type as asked by bamboo abovaea.

If they were blooming when you bought them, as at a florist's shop, or a garden center greenhouse, they won't form new buds until late summer, or early fall this year. Those buds should open spring of 2017.