There is very little work to do this month apart from brushing away leaves.
Keep off the grass if frozen or waterlogged.
Rake the grass thoroughly. Spike the lawn to aerate and stimulate soil organisms and root growth and apply lawn sand if necessary.
The yearly lawn work programme really starts this month. As soon as the ground conditions are suitable, the first cut can be made. The first cut should merely "top" the grass as close cutting at this stage could result in severe yellowing or browning. Two cuts are generally sufficient this month.
Mow often enough to stop grass growing away. Dig out patches of coarse grass or resistant weed. Re-seed bare patches.
Keep mowing increasing the frequency as required. Treat with selective weed killers or combined weed/feed preparations if you did not feed the lawn in April.
Summer mowing should now be under way. It should be necessary to mow the lawn twice a week. Raking before mowing is important this month as the combined action keeps runners of clover under control. Water the grass if necessary, and remember to soak thoroughly.
Treat the grass with the second application of fertiliser or weed killer/fertiliser. Water when necessary and rake occasionally. As a general rule the grass clippings should be removed each time you mow. If weather conditions are dry and hot and the grass is weed free, leave the clippings on the lawn to help maintain ground moisture.
Keep mowing regularly and watering as necessary. Fill any cracks caused by drought with a mixture of sharp sand and soil. In dry weather conditions leave the grass longer to help retain ground moisture.
Raise the height of cut to allow the grass to thicken and protect the roots from the winter frost and snow.
Rake out the thatch from the turf and spike the lawn to assist in drainage. Brush in peat and sharp sand.
Use a stiff broom to disperse worm casts before mowing. Keep turf free from leaves.
Apart from brushing away leaves, December is a slack end of a busy year. Keep off the lawn if it is very wet or frozen.