Herbs can be obtained as young plants by collection and/or mail order from most nurseries and garden centres, but a better selection is usually found at specialist herb nurseries which will also be able to give you other tips in connection with their uses — in cookery, or pot-pourri, or for medicinal and cosmetic purposes, for example. Some health food stores and supermarkets are now offering limited varieties in small pots.
If you know anyone who has particularly good plants you can take cuttings quite easily from shrubby and many perennial sorts, and in addition you can split up clumps of most herbaceous types. Seed companies sell packets and kits of seed of the most popular varieties.
Herbs in general prefer a lightish soil in a sunny, sheltered position and if your land is inclined to be heavy you should try to dig in as much sand and humus-forming materials as are necessary to make it pleasant to handle.
Most of them are best planted in the spring after the worst of the weather is over and they can then make plenty of good strong growth before the following winter. The method of planting is the same as for other herbaceous and shrubby subjects.
Young plants should not be allowed to die of drought the first year after planting but in general most shrubby herbs prefer a position which is on the warm, dry side. The herbaceous sorts need more moisture, but should not be drowned.
Evergreen shrubby ones need clipping over or cutting back once during the summer so they can make new and hardened growth before winter. Cut back herbaceous sorts regularly to ensure a supply of young, tender shoots. Cut down in the autumn to tidy up the plant.
Herbaceous perennial types will need splitting periodically to keep them young and in bounds, usually about every three years. A few herbs, like dill, coriander, basil, borage, and parsley are actually annuals or biennials, and should be resown every year.
Slightly tender perennial varieties in cold areas will need to be given some protection in winter. Some form of shelter can be erected if they are subjected to cold winds, or a 2 in. (50 mm) mulch can be used to keep the frost out of the roots, and the crown of the plant, where appropriate. Containerized herbs should be put in a cold greenhouse, or light room or garage when the weather is really severe.
Because young plants are best, keep a supply of replacements handy. You can save seed from your own herbs, especially the annual ones, and sow it under cold glass or in a sheltered spot outdoors in spring and early summer, though this hardly seems worth it for the cost of a packet of seeds, especially as if you once let them seed, they will come up all over the garden, often where you do not want them to.
You can also save seed from the perennial herbaceous and shrubby types, though there are easier and more effective methods. Most herbaceous perennials are best propagated by division, or by removing small rooted portions and growing on in a pot.
Shrubby herbs grow well from cuttings. Insert 3 in. (75 mm) long tips of shoots or branches 1 in. (25 mm) deep in a good potting compost in small pots in late April and May. Remove the leaves first from that part of the stem which is in the compost. You can dip the ends in a hormone rooting powder, but they will root quite readily without. To cut down transpiration and water loss from the compost you can keep the cuttings in a big, inflated, clear polythene bag for a week or two, but be very careful they do not touch the bag sides or they will start to rot — in fact, all cuttings are inclined to rot more easily with this method, though you will not get problems with wilting in the early stages. Keep in a sheltered, shaded position outdoors until they have rooted, which only takes a few weeks for most types.
Some perennial herbaceous ones, like mint, can also be propagated this way, but are more satisfactorily propagated by division.