If there is frost during the winter both farmer and gardener are pleased because they say the frost "mellows" the ground; you can see what they mean if you walk on a frosty morning over a ploughed field.
"Lessons on Soil"
E. J. Russell
In all, there is also a good deal of personal and literary satire, which tones and mellows as it proceeds.
"The English Novel"
George Saintsbury
We said the autumn and the winter were gone; and it was in one of those latter days in March, when, like a hoyden girl subsiding into dawning womanhood, the rude weather mellows into a softer and tenderer month, that, by the side of a stream, overshadowed by many a brake and tree, sat two persons.
"The Disowned, Complete"
Edward Bulwer-Lytton