Hundred Elms Farm was probably named after the avenue of elm trees which used to line the sides of Elms Lane from the Harrow Road up to the farm.

The Greenhill family were tenants of the farm from 1817 until the early 20th century, and the 1881 census shows Charles Greenhill, a farmer of 147½ acres, living at "100 Elms Farm”.

His father, William Greenhill, had made it a dairy farm (keeping cows to produce milk) by the 1860s. This type of farming needed more workers, so cottages were built for them to live in, including Keppel Cottages (now 920-930 Harrow Road) which can still be seen at the corner of Elms Lane.

By the 1890s the farm was selling its milk, cream and butter through a dairy shop in Harrow. Adverts for the shop invited customers to visit the farm at any time to see how its milk was produced. Cleanliness at the shop was ensured by its spotless tiled surfaces, and a specially painted tile mural adorned one of its walls.

In 1918, Hundred Elms Farm and its shop were bought by United Dairies, a company run by Arthur Barham (the younger son of George Barham of Sudbury Park). By the mid-1920s its fields had been sold off for housing development. Although cows could no longer be kept here, the farmyard was retained as a dairy depot by the company, which later became known as Unigate.

Eventually, the former farmyard was no longer suitable for a dairy business, and it too was sold for housing development.

In the 1990s, the Metropolitan Housing Trust built Dyson Court, at the corner of Elms Lane and Perrin Road, on the site, but if you go through these modern buildings you can still see two preserved old farm buildings from the days of Hundred Elms Farm. A 16th century brick building has been converted to flats, while the 1840s farm house is now known as Franklyn Lodge, a residential care home for up to six adults who have learning disabilities.