This section is from the book "Commercial Gardening Vol1", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
When a man intends to grow fruits, flowers, or vegetables for profit his first consideration is the "soil". This constitutes his chief raw material, and he knows that if he makes a mistake in its selection it may lead him to ruin, or become such a drain upon his resources and labour that his life becomes one of drudgery, anxiety, and worry.
In these days there is a danger of a good cultivator ignoring the teachings of his own practical experience, and trusting blindly and implicitly to the dicta of the botanist and chemist, and others whose acquaintance with the actual cultivation of plants may be of the slightest. A man may be told that a certain soil contains enough plant food to last a thousand years, and an elaborate analysis of the phosphates, potash, iron, magnesia, soda, lime, and other essential plant foods will be produced in support of the statement. From a purely theoretical point of view such a statement may be chemically correct, but the said foods may be locked up or combined in such a way in the soil that it would take generations of hard work and a mint of money to bring them into anything like an available condition.
While it would not be wise to ignore the chemical analysis of a soil altogether, the intelligent cultivator will not rely entirely upon it. He will use his own judgment, the value of which will of course depend largely upon his practical experience and observation. He will find a safer guide than mere chemical analysis in examining carefully the vegetation of any piece of land he contemplates cultivating. Here his knowledge of plants, their relationship to each other, and the natural conditions chat suit them will be of great value to him.
"Nor every plant on every soil will grow: The Sallow loves the watery ground, and low; The marshes, Alders: Nature seems to ordain The rocky cliff for the Wild Ash's reign; The baleful Yew to northern blasts assigns, To shores the Myrtles, and to mounts the Vines".
On poor, sandy, or gravelly soils, for instance, he will notice such plants growing as the Lesser Bindweed (Convolvulus arvensis), the Musk Mallow (Malva moschata), the Hairy Cinquefoil (Potentilla argentea), the Gallic Catchfly (Silene gallica), the Speedwell (Veronica officinalis), the Hawk-weed (Hieracium Pilosella), Chamomile (Anthemis nobilis), Shepherd's Purse (Capsella Bursa-pastoris), Corn Bluebottle (Gentaurea Cyanus), Poppy (Papaver Rhoeas), Heather (Calluna vulgaris), Spanish Broom (Cytisus scoparius), Bracken (Pteris aquilina), Sterile Brome Grass (Bromus sterilis), etc.
On wet or marshy soils the following weeds may be found: Dog's Bent Grass (Agrostis canina), Cuckoo Flower (Cardamine pratensis), Marsh Thistle (Cnicus palustris), Horsetail (Equisetum arvense), the Marsh Galium (Galium palustre), Corn Spurrey (Spergula arvensis), Comfrey (Symphytum officinale), Flowering Rush (Butomus umbellatus), Bulrush (Typha latifolia, T. angustifolia), Forget-me-Not (Myosotis palustris), Rushes (Juncus spp.), Sedges (Cyperus spp.), Loose-strife (Lythrum Sali-caria), Willow Herb (Epilobium), Common Carrot (Daucus Carota), Butterbur (Petasites vulgaris), Water Ragwort (Senecio aquaticus), Yellow Meadow Rue (Thalictrum fiavum), Ivy-leaved Crowfoot (Ranunculus hederaceus), Great Spearwort (Ranunculus Lingua), the Lesser Spearwort (R. Flammula), the Marsh Marigold (Caltha palustris), Watercress (Nasturtium officinale), Sundew (Drosera), Mare's Tail (Hippuris vulgaris), Water Milfoil (Myriophyllum), Pennywort (Hydrocotyle vul-garis\ Water Parsnip (Sium), Valerian or All Heal (Valeriana), Bur Marigold (Bidens cernua), etc.
On chalky or limestone soils: the Pasque Flower (Anemone Pulsatilla), the Stinking Hellebore or Setter Wort (Helleborus foetidus), the Baneberry or Herb Christopher (Actoea spicata), Whitlow Grass (Draba muralis), Penny Cress (Thlaspi perfoliatum), Cheddar Pink (Dianthus coesius), Goldilocks (Aster Linosyris), the Fetid Hawk's Beard (Crepis foetida), Wild Sainfoin (Onobrychis sativa), Chicory (Cichorium Intybus), Fumitory (Fumaria officinalis), Bladder Campion (Silene inflata), etc.
On clayey soil or very heavy loam will be found Docks (Rumex), Coltsfoot (Tussilago Farfara), Creeping Bent Grass (Agrostis repens), Floating Foxtail Grass (Alopecurus geniculatus), Sow Thistle (Sonchus arvensis), Rest Harrow Ononis spinosa.
Where, however, one notices the Hawthorn hedges, Wild Plums and Sloes, the Elms, Oaks, Beeches, Ashes, and Lime trees growing luxuriantly, the soil bearing them, or adjacent, may be looked upon as the best for general gardening or farming. It contains a fair mixture of sand, clay, lime, and decayed organic matter (humus), and such a soil is likely to yield the best results - if it is properly cultivated, but not otherwise. The following weeds also indicate a good loamy soil suitable for the cultivation of Fruits, Flowers, and Vegetables, viz.: Thistles, Stinging Nettles, Groundsel (Senecio vulgaris), Goosefoot or Fat Hen (Chenopodium album), Annual Sow Thistle (Sonchus oleraceus), Dandelion (Taraxacum officinale), Chickweed (Stellaria media), etc.