When must the pitch and outfield be mown and swept during a match?

Who mows (Law 9.3.1): all mowing before the match is the Ground Authority's sole responsibility. All mowing after that is done under the umpires' supervision.

How often (Law 9.3.2): so conditions stay as even as possible for both sides, both the pitch and the outfield are mown on every day of the match on which play is expected, if ground and weather allow. If the outfield can't be fully mown for other reasons, the Ground Authority must tell the captains and umpires what will be done instead.

Deadlines on each day (Law 9.3.3):

Clearing debris (Law 9.2): the pitch must be cleared of debris

• before each day's play: after mowing and before any rolling, between 30 and 10 minutes before the start;
• between innings, before any rolling; and
• at all meal intervals.

Any method the Ground Authority chooses can be used, unless the umpires think it could damage the surface, in which case it must be done by hand. Debris may also be cleared by hand before mowing and whenever either umpire thinks it's needed.