I should have mentioned that our greens are very well used in general by residents of the estate, for walking dogs, playing ball, kids playing etc.
And in the current lockdown, it is a large open space that people can go out onto with their DCs or dogs safely. We were able, before it became stricter, to have coffee out there sitting 2 m apart and just catch up with neighbours. There has still been a lot of sport - of varying levels of expertise - going on (from the toddlers with a Dad and a ball, to the teens (brothers) with a bag of balls, a goal and a dad who is a coach giving them a full session, and everything in between). There have been a variety of sports too - soccer, gaelic football, hurling, hockey, tennis, athletics). So keeping the grass maintained at a reasonable height is important for a lot of that activity to continue.
And that is activity within the guidelines, because it is only family groups - we know them all and they are sticking to not having friends/neighbours involved. Regardless of what would normally happen. And usually there is only 1 group out there at the time - but it is a big enough green that there could be 5/6 groups there well spread out and maintaining the social distancing necessary.