ON clear nights when the moon rises white as a cut potato, and the stars look as sharp as glass, you can almost smell the arrival of frost.
Recent nights have been cold, crisp, and crystal clear, so morning frost has become an added feature to life in these Covid-filled nights.
Beware, however, for this is weather at its most clandestine. On no account take frost warnings lightly for it is formidable and insidious in its power.
The liquidity of a lake will turn to glass if it arrives suddenly and persists for more than a few nights.
A dripping tap can be stopped by a sudden seizure of hoar frost and water pipes in an attic can expand to bursting point long before midnight grows old.
Frost relies on the element of surprise to gain its greatest effects.
It may manifest itself by creating an all-white landscape after early night-time rain or turning foliage black on a reputedly hardy plant.
That fancy pot on the patio, which you meant to bring under cover so many times, may be first to fall victim to frost and water expansion if allowed to remain longer than just one night in the open.
The days in early December are still shortening and if you are anxious to go inside earlier from the outside chill, do not forget to lift the pot as you pass by. It may be your last chance to save a valuable piece of garden sundry.
Whether you have purchased terracotta pots in a warm country or from pottery here at home, it is vital to take precautions, so they will not crack, shatter or flake during winter freeze-ups.
Most glazed and ceramic pots that come from abroad are not frost-proof and as such are best as ornamental summer containers only.
Unlike terracotta pots made in this country by the likes of Corley Bridge Pottery in Wexford (theirs are guaranteed frost-proof) imported terracotta is often made from clay that absorbs excessive moisture and is fired at lower temperatures.
These pots can crack and flake in the cold even when empty, not to mention when filled with wet compost and bulging plant roots.
With pots not guaranteed frost-proof, aim to be safe rather than sorry so empty them of soft bedding and the like then wash and store before Christmas.
If you cannot do this (they may contain permanent residents or be too heavy to move easily) then at least try to manhandle them in nearer the house walls and raise their bases on three or four clay 'feet' (these are available wherever clay pots and containers are sold) so that moisture drains more easily and the base is not sitting directly on super-cooled pavers or concrete.
In very exposed areas cover the pot with bubble-wrap plastic inside, of which you have stuffed straw or well-dried hay.