Gardener's Dictionary (1735)
Philip Miller

ASHES are esteem'd by some a good superficial Dressing of Corn and Meadow Land, as they give a new Ferment to such Lands as are in any Degree sluggish and unactive, and inrich those which are jejune and slow, being endow'd with singular Qualities to make them prolifick.

All Sorts of Ashes do, indeed, contain in them a very rich fertile Salt, and are the best Manure of any to lay upon cold, wet Land, but then they ought to be kept dry, that the Rain may not wash away their Salt. Experience has shewn, that the Ashes of any Sort of Vegetable, are very advantageous to Land, by the Improvement that has been made in most Places in England, by burning Bean Stalks, Fern, Furze, Heath, Sedge, Straw, Stubble, etc.

Coal-Ashes, or such as are made of Newcastle, Scotch, and other Pit-Coal, are much recommended by some; but the first are most approv'd of, because they contain a greater Quantity of nitrous and sulphureous Matter than the others do, tho' the rest are good.

But these ought to be apply'd superficially, and not so near the Roots of Plants; and if so, there are few Plants but will receive Benefit by them, by their nitrous and sulphureous Qualities being wash'd down by the Rain, which will open by the Strength of Water, and cause it to heave in some Degree, as Lime will do when Water is thrown upon it.

Wood-Ashes are commended as the Principal or superficial Dressings for Land, in that they contain a vegetative kind of Salt.

Kiln-Ashes, i.e. such as are made of Straw, Furze, etc. are by some accounted as good as any of the spirituous Improvements of Lands that are lightish; but for such as are heavy, they are look'd upon as scarce solid and ponderous enough. These Ashes, the Maltsters in the West-Country sift over their Corn and Grass. These are suppos'd, by their Heat, to cause a Fermentation, a Hollowness and Looseness in the Mould, by which means the Rains enter it the more easily, and dispose the Earth for giving up an Assumption of its vegetative Augment.

But these being light, ought never to be strew'd nor sifted in windy Weather, because they would be blown away; and if it can be so order'd as to be done just before Snow or Rain, it would be the better,

Soap-Ashes, (i. e. after the Soap-Boilers have done with them) are very proper for Lands that are very cold and sour, and to kill Weeds of all Sorts. And Sir Hugh Plat mentions one at Ware, who having a Piece of Land over-run with Broom and Furze, manur'd it with Soap-Ashes, and had an incredible Crop of Wheat for six Years successively.

Pot-Ashes, after the Potash Men have done with them, are esteem'd good for most Sorts of Land; but as they have been wet, and so most of the Salt drawn off by the Lee, they ought to be laid on much thicker than other Ashes.

Turf-Ashes are very good for all Sorts of Land, but especially for Clay-Lands; but will be much better if mix'd with Lime.

But all these Ashes ought to be kept dry from the Time they are made till they are used, for else the Rains will both wash away their Goodness, and also make them clod, especially some of the last-mention'd, so that they will not spread.

And besides, one Load of Ashes that have been kept dry, will go as far as two that have been expos'd to the Rain: And Coal-Ashes, if moisten'd with Chamber-lye or Soap-Suds, will greatly add to their Strength.

All calcin'd Vegetables cause a fiery Heat and Vegetation, and when Wet comes, set the Ground to work, by a subtle Insinuation, unlocking the Clods, and quickening the Sluggishness of the Earth; according to that established Maxim among Naturalists, That all Fermentation is caus'd by the Interpostion or Mixtures of different Qualities one from the other.

It is after this manner that Coal-Ashes operate so admirably in loosening and mouldering stiff, clayey Grounds, and as it is usually term'd, making it rough, ashy or sandy-like; And, after the same manner, Sand mix'd with Clay does well, especially when it is impregnated with saline Qualities.