How and Where to Grow Herbs
Herbs are so useful in the kitchen that they merit a part of the garden to themselves — ideally, a sunny position near the kitchen door where they can be picked without bother.
This is not always possible, but herbs are so adaptable that they will thrive among flowers in a border, in pots on a patio, in a window-box, or in some cases in pots on an indoor window-sill. The soil or compost should be free-draining and fertile, but need not be especially rich.
Before planting an outside bed as part of the ornamental garden, draw up a plan that will make the most of contrasting leaf shapes and colours to give the plot an interesting appearance.
Take care to plant the taller herbs, such as angelica, dill, fennel and rosemary at the back; and smaller ones, such as chives, marjoram, parsley and thyme, near the front.
Some elaborate herb gardens have been laid out, including a chess-board design in which different herbs are planted in the 18 `black’ squares, with paving or gravel filling the ‘white’ squares. But these are too troublesome for all but dedicated herb growers.
Such designs have the merit of placing all the herbs within easy reach for picking. The principle can be followed in a small garden by using paving stones in the shape of a cross.
The choice of herbs depends on taste, but no herb garden can be complete without chives, mint, parsley, sage and thyme.
After these, the herbs most likely to occur in recipes are bay, borage, dill, fennel, marjoram, rosemary, savory and tarragon.
But part of the interest in growing herbs is to try something different, so a larger bed can include angelica, balm, burnet, chervil, coriander and lovage.
Growing herbs in a flower border
Some herbs make an attractive addition to the flower border. Angelica, for example, can reach 10 ft (3 m) high in rich, moist soil, and makes an impressive backdrop for other flowers.
Other herbs worth growing in the border are fennel — of which there are bronze and purple forms — with its feathery foliage; borage, which has star-shaped, blue flowers; and sage, with its grey leaves — sometimes variegated and spikes of blue or white flowers.
Parsley and chives make an interesting and productive edging.
A herb garden on a patio
All herbs, except perhaps the tall angelica, can be grown successfully in tubs, boxes or flower pots on a patio or in a town garden.
In some ways this is a more practical method of growing herbs than in the open garden, since the roots of invasive plants such as mint are kept in check. Pots containing chives, parsley, bush basil and marjoram can be brought indoors for winter.
Ensure good drainage by drilling holes in the bottom of boxes, and put a layer of rubble at the bottom of all containers. A potting compost, such as John Innes No. 1, will give more reliable results than ordinary garden soil.
Sow or plant as for herbs in the garden and keep the containers well watered, especially during periods of drought.
Every March or April remove 2-3in (50-75 mm) of soil from the tops of tubs containing perennial herbs, such as bay, thyme or sage and replace this with fresh potting compost, and apply a liquid feed once a fortnight between May and September.
Growing in window-boxes
Low-growing herbs, such as chives, parsley, pot marjoram and winter savory, can be planted in window-boxes in the same way as in containers on a patio.
If tall herbs, such as tarragon or fennel, are grown, pinch out the growing points regularly to restrict the size of the plant. Plant mint in a separate box or it will soon smother the other herbs.
Growing herbs indoors
The kitchen window-sill may seem the most obvious and also convenient place to grow herbs indoors, but often it is the least successful.
A better place for an indoor herb garden is by a window or glass door in a room where there is plenty of light and also lower humidity.
Grow indoor herbs in John Innes potting compost No. 2, which is richer than the soil they need outside. Even then, do not expect them to be of the same quality as herbs grown in outdoor beds during the summer.
During February sow parsley, chervil and basil in separate pots. Let some of these plants grow on for early picking indoors, and plant out the remainder in the open in late May or early June.
Towards the end of September start potting up some of the perennial herbs that have been growing in the open during the summer. Sage, marjoram, chives and mint are among the most suitable.
Parsley can also be treated this way, but it is better to sow seed directly in a pot in June and bring it indoors in late September.
The size of the pot will depend on the size of the roots, but most will do well in 5-6in (130-150 mm) pots.
Most herbs, both annual and perennial, can be raised from seeds.
It is also possible to increase your stock of perennial herbs — or to replace old, straggly plants with new ones – by taking cuttings and setting them to root in pots containing equal parts (by volume) of peat and sand. Alternatively, root them in a seed compost.
Dipping the base of the prepared cuttings in hormone powder encourages rapid rooting.
You do not need a greenhouse to root cuttings but a garden frame is a great help. This is not only for the warmth it provides but also for the still, humid conditions inside the closed frame.
If you do not have a frame, cover the pot of cuttings with a plastic bag and secure this with a rubber band to retain moisture. Place it on a window-sill.
The sort of cutting to take depends on the type of herb you are propagating:
Herbs propagated by this method include hyssop and marjoram in April or May, and rosemary in July or August. However, hyssop and rosemary can also be propagated as heeled cuttings in late summer.
Remove the top 3-4in (75-100 mm) of a main stem just below a leaf joint, or node. Pull off or cut away the lowest pair of leaves and pinch off the soft tip. Plant the cuttings firmly in a 3in pot of compost — several to a pot — water them and place in a frame.
The cuttings should root in from four to six weeks. When rooted, pot them individually in 3in pots of potting compost and grow them on in a ventilated frame.
Take this sort of cutting when propagating thyme in May or June, and bay or sage in late summer.
Cut off semi-ripened shoots from the parent plant, complete with a heel, or sliver of wood, from the main stem. To do this, make a slanting cut into the main stem just below the side-shoot joint, then make a similar cut above the joint to remove the shoot. A sharp knife is needed, so take care not to cut yourself.
Rooting and after-care is the same as for nodal cuttings.