[2] Ralfs's father died at Mudeford near Christchurch[3] before John was a year old, and the children (two sons and two daughters) were brought up at Southampton by their mother.

At Torquay, where he moved on account of lung disease (probably tubercular in origin[2]), he married, in 1835, Laura Cecilia, daughter of Henry Newman.

In November 1837, for the sake of the mild climate, he settled at Penzance, and, having abandoned his profession, dwelt there for the rest of his life.

[1] Joseph Dalton Hooker and Thomas Henry Huxley, with the Philosophical Club of the Royal Society, set up a charitable collection to provide Ralfs with an annuity — the appeal was so successful that in addition to providing Ralfs with an income, a fund for the "relief of necessitas [sic] Scientific Men" was also established.

He left his collections of microscopic slides, 3,137 in all, to the botanical department of the British Museum, but as the will had not been witnessed, it did not take legal effect.

Miles Joseph Berkeley, to the Edinburgh Botanical Society, and for many years his articles appeared in its Transactions and in the Annals of Natural History.

[2] Arthur Hill Hassall long corresponded with Ralfs, who suggested that they should render each other assistance in their inquiries.

Charles Darwin in his Insectivorous Plants gracefully referred to those supplied to him by Ralfs from the neighbourhood of Penzance.