Growing Herbs - The Basics
Growing Herbs –The Basics
PLANT TYPES
Most herbs are easy to grow once you understand their habits and the conditions they prefer. Herbs can be classified into six main plant types.
Annuals
Annuals live for only one growing season. They die after flowering and producing seed. (eg. dill, coriander, salad rocket). Some plants that would be perennial (ie. everlasting) in their native conditions, but cannot tolerate our Irish winters, are treated as annuals (eg. basil, lemongrass).
Biennials
Biennials live for two growing seasons. In the first year they provide plenty of green leaves, in the second year they flower, produce seed and die. (eg. parsley, chervil).
Herbaceous Perennials
Herbaceous Perennials are long lasting plants that die back in winter.
(eg. chives, lovage).
Evergreen Perennials
Evergreen perennials are long lived plants that retain their foliage all year. (eg. oregano, clove pinks).
Evergreen Shrubs
Evergreen Shrubs also retain their foliage throughout the year. Most shrubby herbs are of Mediterranean origin (eg rosemary, sage, thyme, lavender).
Trees
Generally, trees are not thought of as herbs, but many of them are important medicinal plants (eg elder, hawthorn, gingko).
Where to grow herbs - situation
Contrary to the popular opinion that all herbs need a sunny site, many thrive in moist, semi-shaded conditions. Plants that produce lush, green leaves (eg parsley, chives, chervil, sorrel) will do well in partial shade. In full sun the leaves will be tougher & tend to scorch. Plants with small or narrow, tough leaves generally need full sun and well-drained soil, to thrive (eg lavender, rosemary, sage, thyme).
Propagation Methods
Seed Sowing
All hardy annuals, biennials and hardy perennials can be sown directly outdoors, from about the middle of April through to September, into a well-prepared seedbed. Rake in lightly and keep well watered and weeded, until the plants are established. Plants produce seed after they have flowered, so in natural conditions they self-seed from late summer through to early winter.
Tender annuals and perennials are best sown in spring, in pots, plug trays or modules. Use a fine, seed grade compost. Fill pots or trays to the brim with compost. Tap the pot or tray to settle the compost, and top up if necessary. The compost needs to be neither too loose or too compacted. Water the sowing containers well and allow to drain.
Sow seed sparingly on the surface. Cover larger seed with its own depth of compost or vermiculite. Cover the container to retain warmth and moisture and check every few days for signs of germination. Do not allow the surface of the compost to dry out. If necessary, use a hand mist sprayer to gently water the surface, without dislodging the seeds. When the seed has germinated, move the trays into the light, but protect from strong direct sunlight.
When the young seedlings have produced two true leaves (or are about 4cm in height) it is time to pot them on. Water the pots or trays and allow to drain. Transplant the seedlings into small pots. (I use 8cm square pots). Treat the seedlings gently. Rough handling of stems or roots of the young seedlings at this stage will set them back. It is really important to ease the seedlings out of their pots or modules. Squeeze them from underneath to loosen the root ball of the the young plants. It is best to handle the leaves only and preferably without using any gloves. If you need to use gloves, (and many people do due to skin conditions or allergies) you can buy surgical gloves from most pharmacies.
When the seedlings have been potted on, they need to be watered. Use the finest watering setting on your hose or watering can. Keep the young plants out of direct sunlight for a week or so, until they are perking up and looking happy.
Before planting out into the garden, containers on the balcony, window boxes or hanging baskets, the plants need to be 'hardened-off'. This means you gradually acclimatise them to their final growing positions. If the weather is nice, warmish, and not too wet or windy, put the plants outside during the day and bring them back into shelter overnight. Do this for a couple of weeks. When all danger or frost is over, plant your herbs into their final position.
If you are growing them in the garden, you just need to remember to keep them well watered in the first few weeks, especially if the weather is dry. They will establish very quickly and thrive. In no time they will need very little care apart from a tiny bit of weeding. You will have herbs for life!
If you are growing in containers, your herbs will need a little more attention. When the weather is very dry they will need regular watering. Placing a tray under the pot will help to retain water
Late-summer and autumn sown seedlings may need some protection over winter, ie. an unheated polytunnel, greenhouse or cloche. Horticultural fleece is also very useful.
Display of herbs on Gaby’s course:”Growing great herbs”.