What is the collective noun of tuft?

There isn't a specific collective noun for a group of tufts. However, depending on what the tufts are made of, you could use a more general collective noun:

* For tufts of grass: A swathe of grass

* For tufts of feathers: A clutch of feathers

* For tufts of hair: A mass of hair

* For tufts of wool: A bale of wool

Ultimately, the best collective noun will depend on the specific context and the type of tufts you're describing.