Herbs and their Cultivation

The joy about herb gardening is that it is easy. Herbs are not faddy plants which demand, for instance, such niceties as acid soil, regular feeding, a lot of manure, shade at midday, mulching with oak leaves, and so on. They do like shelter from wind but what plant, or person for that matter, does not like protection from all the gales that blow? Given a reasonably average soil, they should all grow perfectly well, and indeed often the trouble is, as with vegetables, they produce far more vegetation than one can comfortably use. Still, if they are being grown mainly for ornament, even this will not matter.

Probably most important of all is to choose the right position in the garden. Somewhere facing south and/or west, with a barrier against the north east winds, and some kind of screen to break the force of the south west gales of summer, will make a very good site for herbs. If the ground slopes a little towards the sun, it is even better, but this is not so important. Try to avoid a part of the garden which tends to remain frozen long after other parts have thawed; many herbs are natives of the hills and coasts of the Mediterranean and are used to baking heat in summer and dry winters with little if any frost. Actually, it is not so much low temperatures, as the alternation of cold and warmth in winter combined with constant damp which we get in Britain, that is responsible for killing plants.

If there is a suitably sunny position, but no barriers to wind, a temporary screen of hessian or wattle fencing will provide this, while a hedge grows up. Even trellis work or strands of wire will be effective, if climbing plants such as sweetpeas, nasturtiums, runner beans or ornamental hops are grown over them.

The hedge can be formal or informal, tall to give a completely enclosed garden, or low growing, in the pattern of the Elizabethan knot garden. The plants forming the hedge need not be herbs, though there are some very good ones for this, for instance, rosemary, Rosagallica, and sage.

Soil which becomes sodden in winter or after prolonged rain must have its ability to drain water away improved. This can be done by forking in coarse sand while preparing the soil, 3-4 lb per sq yd. Peat will help the soil particles to form into crumbs, and so help to make room for air and water to circulate. It can be mixed in at the rates the suppliers suggest; leafmould at 7 lb per sq yd, or rotted garden compost at a lower rate because it contains more plant food. For heavy soils these preparations can be made during the late autumn or early winter. Soil which is already quick to dry out will only need the addition of organic matter, a month or so before sowing or planting. If mixed into a soil earlier, it is in fact liable to be washed out by the winter rains.

If the soil is really short of plant food, as town garden or old garden soils often are, you must give some kind of artificial fertiliser before sowing or planting. Herbs are said not to require a particularly fertile soil, but it is no good expecting them to do well if the growing medium is dead, that is, if there is neither mineral nutrient or humus in it.

Some people will say that artificial fertilisers should never be used, but in some soils plants will never get going without them no matter how much humus is put in. Once the soil fertility has been built up and the soil brought to life again, by feeding and manuring and regular cultivation, then it may be possible to do without powder and granulated fertilisers, and rely completely on a little mulching (spreading a surface layer) with compost, leafmould, or peat.

In short, preparation of the soil before planting herbs

should consist either of adding coarse sand and peat/ leafmould/compost or similar material if drainage is bad, in late autumn, or it should consist of mixing in organic matter about a month before planting or sowing. In both cases fertiliser can be given ten days or so before sowing or planting at 2-3 oz per sq yd., raking it into the top 2 or 3 in. or so.

A word about compost making here. Compost heaps first came on the scene when a shortage of farm manure began to be apparent, as horse-drawn ploughs were replaced by tractors and as towns became bigger and more distant from sources of supply. Whereas farm manure is mainly animal organic matter, compost is mainly vegetable in origin, containing rotted down leaves, soft stems, flowers, grass cuttings, in fact all kinds of soft vegetation; household refuse can also be included such as tea leaves, orange skins, potato peelings and so on. The ideal size of the heap is about 5 x 4 x 5 ft.

Such a heap heats up rapidly and to a considerable temperature if built quickly, using the above materials, with the addition of a sprinkling of lime alternating with a sprinkling of nitrogenous fertiliser on every 6-in layer of vegetation. A very wet or dry heap will not rot, and adjustments must be made to either condition.

A heap started in spring should be ready for use about six to eight weeks after completion; one started in mid-summer probably will take all the winter to rot down completely to a dark brown crumbly substance. Complete rotting of the heap will be assisted if it can be raised off the ground slightly so that there is air beneath it, which will be drawn up through the centre. If the heap is built up round posts, their removal when the heap is finished will improve ventilation even more. Wooden slats or wire netting will help to keep the heap tidy; for small gardens wire bins can be obtained which are easily dismantled and packed flat when not wanted.

The benefit to the ground which results from using compost material made in this way is out of all proportion to the quantities added. The bacteria and worms contained in it continue to live, feed and work not only in the compost but in the soil also, water and air become much more mobile,

particles of plant food dissolve in the soil moisture much more readily, so there is more nutrient for roots to absorb, and so on and so on. The end product of compost-treated soils cannot help but be better herbs in all respects, whether healthier, stronger, larger, more aromatic or with increased food and medicinal value.

As with other garden plants, herbs can be annuals or perennials. The annuals are grown from seed and will flower, if allowed to, and die down in one growing season, between spring and autumn; the perennials will grow from seed or small plants obtained from cuttings or division. Some of the perennials will also die down in autumn so that only the rootstock remains, but some are evergreen, and the leaves can be used all through the winter. Those that grow conveniently like this are: salad burnet, chervil, parsley, rosemary, thyme, sage, lavender, bay, hyssop and winter savory; some other herbs can be encouraged to go on producing top growth into early winter if covered with cloches, or through the winter if potted and brought indoors, such as chives, mints, lemon balm, pot marjoram and lemon verbena. Some of the shrubs may not survive a severe winter — for instance rosemary, sage, bay and hyssop, and if it looks like being prolonged and chilly, they must be protected from the cold as far as possible. A thick, wide-spreading mulch will help the roots, and enclosing the top growth in straw or conifer branches wrapped round with polythene, securely tied against wind, will keep the worst of the cold out. Leave a space at the top for a little air to penetrate and remove the wrappings as soon as it is safe to do so.

On the whole, about two thirds of the commonly grown herbs do die completely or to ground level, in autumn, and so for some at any rate, one must resort to preservation in order to use them between October and April. With modern methods, such as green drying, or deep freezing, the flavour and aroma can be retained almost in toto, and lack of fresh material need not be a deterrent to herb cookery, or any other uses to which they may be put. Most herb seeds are sown in spring in March or April, depending on the weather and the area. There can be a difference of four of five weeks

between sowing dates, according to the air temperature and the rate at which the soil in your garden warms up, and it is much better to sow later than to rush the seeds into the ground, only to have them rot in cold, wet soil.

In any case, waterlogged soil cannot be broken down to the fine tilth required for seed sowing; it needs to be almost breadcrumb structure. Digging, knocking down the lumps with the back of the rake, and then repeatedly raking will gradually reduce it to the fine state in which seeds will germinate and the seedlings can establish and grow. Take out the weeds at the same time, particularly the roots of the perennial kinds, such as bindweed and couch grass; also remove debris such as stones, sticks, glass, pieces of clay pot, marbles, tin cans, and all the other clutter that is likely to be found in the average garden soil.

In the border or vegetable garden, herb seeds are most conveniently grown if the seeds are sown in rows or drills, as vegetables are, drawing out a shallow drill lA—½ in. deep depending on the size of the seed. As the seedlings will, in most cases, need thinning later, it pays to sow the seeds sparingly in the first place. Choose a calm day, when the soil is nicely moist, give it a final rake down, and cover the seed thinly. If the soil structure is not good, germination can be encouraged by lining the drills with one of the soilless seed composts, suitably moistened.

Some herbs are grown from rooted cuttings, particularly the shrubby ones, and these are taken generally in summer, using soft tip or semi-ripe shoots. The majority which are propagated in this way root easily and it does not take long to increase or replace one’s stock. The tip cuttings, about 3 in. long are put round the edges of 3-in. pots, in one of the proprietary cuttings composts, covered with a polythene bag secured with a rubber band, and put in a warm shady place until they begin to lengthen. When this happens, they have rooted, and may be potted on separately. Semi-ripe cuttings 5 or 6 in. long are taken later in the summer and need only be put, in their pots, in a cold frame or under a cloche out of doors. They will take longer to root and are usually best planted out in the spring following rooting.

Some herbs can also be propagated by division in spring or autumn, as herbaceous perennials are.

Whatever method of increase is chosen, once the young plants have settled down and are growing well, the routine cultivation through the season need only consist of thinning the seedlings, hoeing or hand weeding, watering when the weather is very dry, and perhaps giving the occasional liquid feed. Don’t overdo the feeding, however; in many soils it will not be necessary, and too much tends to make herbs less aromatic and less well flavoured. They become soft and leafy, and it is the more hard grown kinds that contain the most in the way of essential oils, nutrients and minerals.

Where the appearance of the herbs is important, for instance in a herb garden or border, or when they are grown mixed with other plants, some will need trimming and cutting back, to keep them tidy. They can look very straggly when they have finished flowering, and get blown about and flattened by the wind. The small shrubby herbs tend to get unkempt unless sheared back occasionally.

Fortunately troubles such as insect pests and fungus diseases are few and far between as far as herbs are concerned; it has been said that they carry their own built-in resistance to such invasions, which is perhaps why they have such considerable medicinal values. Such pests and diseases as they do get are specific to the herb concerned and will be mentioned in the individual description in the alphabetical list, together with the remedy.

Container grown herbs

Two points are particularly important for growing herbs in this way: good compost, and good light. As with any pot or box grown plant, good compost is essential, that is, one which is well drained, and to which not only has plant food been added but in the right proportions. The John Innes compost No 1, is very suitable containing, as it does, 7 parts by bulk good loam, 3 parts peat and 2 parts coarse sand, together with 4 oz of the J.I. base fertiliser and ¾ oz chalk, to each bushel of the mixture. No 2 and No 3 have twice as much and three times as much respectively of the base fertiliser and

chalk. These composts can be bought ready made up, from chain stores and garden shops.

Sunlight is most important, so herbs should be put in a sunny position if possible, otherwise in the best light there is, whether outside on a windowsill or balcony, or indoors on a window ledge. If out of doors, try to find somewhere that is not plagued by wind and if inside, give them even temperatures and a humid atmosphere as far as possible.

Herbs seem to do best if grown in the larger containers, such as window boxes, troughs, and shallow tubs. They can also be grown in pots; the 4-in. size is the smallest that can be satisfactorily used for the majority of herbs. When planting in clay pots, put a little drainage material at the bottom of the pot, such as crocks (pieces of broken clay pot) with the curved side uppermost, and then fill in with compost to about half full. Sit the plant on top of this in the centre of the pot, and fill in with compost round it, firming it down with the fingers, and leaving ^in. space at the top for watering; water in lightly to settle the plant into the compost. Re-potting, or potting on into larger pots, is usually done in spring.

Whatever else you do when watering container-grown herbs, don’t give them a dribble every day. Give them a good watering which fills the space between the compost surface and the rim of the container, let any extra water drain through the drainage hole, and then leave the plant alone until the surface soil begins to dry; when this happens, it usually becomes lighter in colour. A dry pot is lighter in weight than a moist one and, if it is clay, it will produce a ringing tone when tapped with a wooden stick. The rule is: only water when the plant needs it as indicated by these signs, and not, for example, at 10.30 every Thursday morning, or every day as soon as the breakfast washing up is done. Herbs will probably die more quickly from overwatering than any other container-grown plant, so, if you must err, do so on the dry side. Remember, too, that in winter when they are virtually not growing, much less water is needed than in summer.