rikv wrote:

90% of the clippings consist of water.

I don't think that's true... by weight freshly mowed grass clippings
consist of more like 98% water, but depending on conditions that water
can evaporate rather quickly. If one plans to use grass clippings as
mulch it's best to mow on a hot dry day after the morning dew has
disapated and then leave the clipping to dry where they fall and raked
up the next day. When clippings are bagged as they're mowed they will
mold rather quickly. Personally I don't think grass clipping make for
a very good mulch, they won't prevent weeds (in fact will encourage
weeds), they are very poor at keeping soil moist, they encourage
insects, and they become moldy much too easily. Grass clippings are
best left on the lawn where they will become fertilzer (use a mulching
blade).