My beautiful mature oak trees rain catkins this time of year. They create a carpet of brown across my yard and I skim my swimming pool multiple times a day. My gardens are likewise full of catkins. The catkins disintegrate into dust when I sweep them. Can I leave them in the garden as added organic material? Does it do any harm if I sweep them into my garden?
Catkins are basically flower clusters which produce pollen in order for trees to cross or self pollinate. Some trees grow only male catkins and others grow both male & female catkins depending on the tree species. While the pollen produced is borne on the wind and we get it all over our gardens, it is harmless unless you are an allergy sufferer. Besides the wind, a portion of the pollen will be transferred by insects from flower to flower. Once catkins fall off the trees, their job is complete and they are no longer needed in order for the tree to produce seed. Therefore, they can be added to your compost bin or left on your flower beds as a source of organic matter as they will very quickly begin to decompose.