Herbs may be the darlings of natural medicine, but they include some powerful toxins
Herbs are in. Well, actually they've been in since at least medieval times. But now that we're increasingly concerned with being wholesome, organic and natural, herbs are undergoing a renaissance. Nowadays, numerous household and cosmetic products need only mention "restorative rosemary", "soothing aloe vera" or "antiseptic thyme", and one can't get them into the shopping basket fast enough. I'm referring to my own gullible self here, of course.
First, though, I'm going to do the health warning bit. Just because herbs spring from the loins of Mother Earth, it doesn't mean that they're bound to be beneficial to human beings. Some of the most powerful poisons in the world are derived from plants: the castor oil plant (Ricinus communis) gives us ricin, and just a few berries of deadly nightshade (Atropa belladonna) can be fatal. On a less dramatic scale, certain herbs that are fine in small quantities may be harmful in larger amounts, or if taken by certain people (pregnant women, for example). So unless you know exactly what you are doing, or are attending a qualified herbalist, don't use herbs medicinally. End of warning.
In the kitchen though, or around the house, herbs are safe, delightful and delicious. A weary salad can be woken up with a scattering of coriander or flat-leafed parsley. Purple florets of chives dotted over slices of yellow tomatoes are as good to eat as they are to look at. Little lavender bags laid among your smaller clothes make you think of Provence every time you open the drawer. And a tisane of freshly picked and infused leaves sends tingles through your body and soul, in a way that a herbal tea bag never can. (A most reviving cup of tea is served at the Organic Centre in Leitrim. Infuse the following in a pot of freshly boiled water for five to seven minutes, making sure to keep the lid on: mint, lemon balm and fennel, an alpine strawberry leaf or two, and a smidgen of thyme, rosemary and lemon verbena.)
Many of the culinary herbs are members of the carrot family, Apiaceae, which bears flat plates of flower that are very interesting to insects, including bees and butterflies. If you let them bloom, angelica, chervil, coriander, dill, fennel and parsley make excellent wildlife plants. Most of these are tap-rooted, and dislike being transplanted. Chervil, coriander and dill are best sown directly where they are to grow.
Probably the greatest number of herbs belongs to the mint family, Lamiaceae, another group that also attracts flying creatures. Besides mint, this clan includes agastache, basil, bergamot, catmint, hyssop, lavender, lemon balm, marjoram, oregano, rosemary, sage, savory and thyme. They are easily recognised by their square stems, opposite leaves, and flowers that are usually arranged in spires. Mint is a thug in the garden and should be relegated to the most unloved area near the compost heap, corralled by some kind of barrier or grown in a container.
There are several kinds of mint, with distinct flavours and scents: spearmint, peppermint, eau-de-cologne mint and pineapple mint, among others. If you have room for only one variety, grow the chunky and furry Bowles' mint, which is the finest for culinary purposes. Its botanical name, should you wish to impress your friends, is Mentha x villosa var alopecuroides 'Bowles'.
Most herbs revel in a hot position, where their aromatic oils develop most fully. Shy parsley, however, doesn't, and promiscuous mint is happy to spread itself around in any kind of situation. Grow herbs as near as possible to the kitchen, so that you don't have to make an expedition each time you need some leaves.
Lanky species, such as borage, dill, fennel and lovage, are best in the open ground, but almost all others thrive in containers. Put a layer of crocks (pot shards) or bits of polystyrene in the base for drainage, and use a soil-based compost such as John Innes number three, with some added grit, again for drainage.
Basil can be tricky, as it needs a lot of heat, and will grow successfully outdoors only if it is in a pot and in a really warm and sheltered spot. It's better if you can give it a sunny window sill, greenhouse or conservatory. Water only when the compost has almost dried out, and then give it lashings of moisture. Herbs like a fairly lean diet, so if you grow them in pots, feed them about once a month, or when they begin to look wan and pale.
Herbs can be grown in borders with other ornamental plants. Some - sage, marjoram and garlic chives for instance - fit in well with other naturalistic-looking perennials. Parsley, chives, lavender, smaller thymes and prostrate rosemary make decorative, scented bed edgings.
Of course, a dedicated herb garden is a complete pleasure. According to Hans Wieland of the Organic Centre, a two-metre circular bed - with chives, parsley, coriander, marjoram, thyme, lemon balm, rosemary, sage and mint - can be made by three people in half an hour. They're demonstrating this feat again next weekend in Leitrim. Bring your stopwatches.
HERBS FOR HEALTH
The Royal Horticultural Society recommends the following herbal teas:
Chamomile for insomnia and pre-menstrual problems.
Fennel for indigestion and as a diuretic; chew the seeds to relieve bad breath.
Hyssop for coughs and catarrh (do not use if pregnant).
Lemon balm for tension, headaches and upset stomachs.
Lemon verbena for insomnia, and nasal congestion.
Peppermint or spearmint for indigestion.
Rosemary to improve concentration and as a pick-me-up if you're suffering from a hangover (no more than one cup a day).