It’s usually preferable to mow your lawn when it is dry as the grass is much easier to work with in this state, but often (especially here in Blighty!) this luxury doesn’t exist. When mowing wet grass there are just a few things you should keep in mind to ensure that you achieve good results safely.
One of the biggest drawbacks with mowing wet grass is in its irritating tendency to clog up the lawn mower blade and grass discharge chute. If you’re really unlucky this can cause the engine to overload which causes a whole set of problems of it’s own. To avoid these issues you must ensure that the underside of the deck and the blade are cleaned before and after you start mowing. You may also need to clean part way through a mowing session, and if so make sure you follow all the usual safety procedures, turning the engine off and disconnecting the spark plug and so on. A well sharpened blade is probably less likely to fall victim to clogging, and you should therefore keep the blade sharpened for this reason.
If your lawn isn’t cutting as well when it’s wet it can be tempting to move the mower backwards and forwards in an effort to chop the stubborn grass. Do not do this! Not only are mowers not designed to move backwards, they are not safe to use in this way either. A better method is to go over the lawn twice in one session, approaching the grass from the opposite direction on the second pass. It’s also worth keeping the cutting height high so that the mower doesn’t get bogged down cutting through the thick soggy undergrowth.
Remember, always go forwards, never backwards!
It’s worth bearing in mind that wet grass is both heavy and prone to staining anything and everything around it when cut.
The additional weight of water logged grass clippings can put strain on a lawn mower grass collection bag in such a way that it is not designed for. If you do mow when the grass is wet it’s far better to discharge the grass back onto the lawn, and either rake it up afterwards, or leave it to break down naturally as a mulch.
If you allow your mower to discharge wet grass onto your patio or garden path be warned that this can result in the paved surface getting stained. Plan your mowing route as such that the discharge chute is facing away from any paved areas if possible, or else be prepared to get on your hands and knees with a scrubbing brush to get rid of those pesky grass stains!