IT is often said of Memories that we haven’t got the foggiest idea about many of the subjects we discuss, and that is certainly true of this item.

A few weeks ago we told of how 150 years ago a spark from a locomotive on the East Coast Mainline had set fire to grass near Newton Hall, which was then a stately home in countryside near Durham.

“The flames spread over a fog field, near the hall, and threatened to reach the vinery,” reported the Echo’s sister paper, the Darlington & Stockton Times. “It was deemed necessary to send for the Durham fire engines.”

The term “fog field” intrigued us. We’d stumbled across it for the first time only a few weeks earlier and a reader kindly stopped us in the street to explain that it is a paddock in which the grass has been cut and is beginning to sprout again.

Yes, we replied, but why “fog”? She looked at us blankly – she didn’t have a foggiest.

Billy Mollon in Durham was also intrigued, and sent in an advert he’d come across in the Durham Advertiser of September 1, 1893, which begins: “Fog to let.”

Billy explained: “It is the grass that grows after a hay crop has been taken from a field.”

Yes, but why “fog”? He, too, didn’t have a clue.

So Memories 387 speculated that it was because the hazy mass of new shoots looks like fog rising from a damp paddock…

“Nice try,” said Ron Bryden, “but the fog field is almost certainly a paddock of Yorkshire Fog Grass, holcus lanatus.”

At last, someone who knows what they are talking about.

Yorkshire Fog Grass turns out to be the most widely distributed grass in Britain. Its young shoots are widely eaten by grazing animals like cows and sheep and its digestibility is good, but they avoid it when it flowers as it doesn’t taste so good – only rabbits eat flowering fog grass.

Its flowers have a soft, purple hue to them. The Latin “lanatus” means “covered in wool”, and in the US, this grass is known as “velvet grass”, so it is the flowers on the fog that give it its foggy name?

Has this cleared the fog of confusion?