Hello, as a professional gardener I usually stop maintaining gardens from October time although this does depend on the garden. If there are lots of trees for example then there will be an endless amount of leaves to rake. Some of our customers keep us on to take advantage of other services such as jetwashing and gutter cleaning but we do stop maintaining the vast majority of gardens when Winter arrives.
I would recommend speaking to your gardener. There’s nothing to worry about, this is common practice for our customers to ask us to stop until the following year. Your gardener may be wondering why you’ve not mentioned it yet.