A common gardening mistake is made when doing leaf pickup in late fall and winter. I am specifically referring to when the ground is saturated and the temperature has declined enough for it to freeze. The first part of the mistake is being too controlling--treating a few leaves like litter strewn on the floor of your home. I am convinced this hyper neat freak behavior for the landscape is a form of psychosis related to our disconnection from nature. Compost the leaves rather than putting them in plastic bags like garbage. A second mistake is trying to drive a heavy riding machine on turf when the surface layer is thawed but the underlying soil is still frozen. The interface of the frozen/unfrozen is slippery and the turf (the surface) is easily displaced. When heavy machine or even a walk-behind mower is used on this kind of surface the result is scarring--a wrinkled/rutted lawn. This damage is more common on low-lying areas and in situations where the turf is sparse, usually sites that are partially shaded. Wait until the ground is frozen to use the machinery. Yes, I know it will be a little colder, but simply put on some warm clothing. You will not freeze to death and it will make you feel more alive. Besides, the visual scarring is visible for months and the ruts themselves stay around even longer, and weeds love this kind of disturbance. Also, avoid going fast and making sharp turns as both will increase the likelihood of damage. Many years the soil will not become firm by draining and drying until spring.