Water and heat this time of the year. There also could be other cuses but I doubt it. They are dormant. Norma

Sorry Norma, I must disagree. I doubt it's the heat & I KNOW it's not the water. It's likely moving it while the buds are still developing. If they're not open yet, they tend to drop if the plant is moved, particularly if its orientation to the light is changed.

From most of what I've read, while the buds are still developing, if one changes the plant's orientation to the light, the buds divert their energy to turning back towards the light & they tend to collapse at the neck of the bud & fall off.

I can't think of anything to suggest that will prevent this except don't move them anymore & try to keep them away from drafts or blasts of heat.

I have to agree with pirate_girl. They tend to be really fussy when they get moved while they're budding. Last year, all I did was move a couple thanksgiving cacti from the laundry room to the dining room - and that was enough to make it lose a majority of the buds. That was frustrating. When it starts budding, you need to leave it alone and let it go through the whole process.

Thanks for the replies. I'll leave them where they are - they still have buds, so I might get more flowers. Thanks!

yes i agree too!
if you move the pot,even slightly,the light angle changes and all buds will fall,if the buds are more advanced,they may continue to grow
gary