They can be put in the compost pile, but the best method is to use them for mulch. Mow them into the turf, but rake the flowers from the hard surfaces and toss into vegetable gardens and landscape beds. There is nothing toxic about the material at all.

What can you do with catkins?

The trees are dropping male catkins, which carry the male flowers of the tree. Use them as mulch or throw them in the compost when they start to pile up.

How do you get rid of catkins in mulch?

In areas where there is no grass, feel free to leave them. If the layer of catkins is not thick on the lawn (less than an inch), try mowing. If it disappears with mowing, there is no need to remove it.