The following excerpt is taken from William N. White’s Gardening for the South; or the Kitchen and Fruit Garden, pp. 286-299.
Medicinal Herbs.
A few roots of the most useful of these should be found in every garden. The following is a description of those most used in families, including their medicinal qualities, and ample directions for their cultivation. The medicinal properties of many of these depend upon their aromatic qualities, and they are never so fragrant and full of virtue when grown upon ground highly manured. Chamomile, lavender, rosemary, rue, wormwood, and many others, lose much of their strength when forced into rank growth. Common garden soil, without manuring, is quite good enough. Whenever the plants begin to decline, take away the old surface soil, and apply fresh, or set out new plants in fresh ground.
Medicinal, pot, or sweet herbs, as a general rule, should be gathered when in bloom, and dried carefully and thoroughly in the shade. When thoroughly dry, press them closely into paper bags, or powder them finely; sift, and keep in closely-stopped bottles.
All mentions of the herbs in the listings below are taken from William N. White’s Gardening for the South; or the Kitchen and Fruit Garden, pp.286-299.