What Do You Mean Rake And Destroy Leaves From Elm Trees

Question

One side of our elm trees turn brown… we planted 4 years ago.

Answer 1

That phrase is intended to help prevent the spread of leaf fungal diseases of elm trees as there are no effective treatments. When elm leaves fall, rake them up and dispose of them in the trash, never in the compost pile.

https://www.gardeningknowhow.com/ornamental/trees/elm/diseases-of-elm-trees.htm