Security Deposit Question

We recently moved out of a rental house (back when we had a foot of snow on the ground). Landlord is holding our security deposit to pay for removing unraked leaves, weeding flower beds. No where in our lease does it state that we were responsible for raking/removing leaves. They are telling me it's going to cost around $5k to rake and remove the leaves and clean up the flower beds and basically we aren't getting anything back.

Does this sound normal? The weeding the garden beds was in the lease so that I sort of understand, but raking and disposing of leaves was not mentioned anywhere and I'm honestly baffled. I've always left the leaves on the ground then mow in the spring and that's never been an issue. If there wasn't a foot of snow on the ground when we moved out and they expressed that, I wouldve handled it myself.