The most common reasons for failure with culinary herbs are insufficient light and over watering. Remember most herbs are native to the Mediterranean so like it sunny and dry. If growing indoors keep them on a bright South West facing windowsill and water them sparingly. Most herb plants will do better outside with only a few, like basil or coriander, needing year round indoor cover.
To keep herb plants lush and bushy you should pick regularly during the growing season. It is important to pick off the tips of the stems rather than removing from the base as this will thicken out the plants. Herbs are also often left unfed as they are not demanding plants but a liquid seaweed tonic will do wonders and increase both the vigour and the flavour of your plants.
Soft and woody herbs There is no comparison between the taste of freshly picked herbs and the dried versions. The increased flavour is especially apparent in soft herbs like basil, chives, marjoram and coriander. Soft herbs are best used at the end of the cooking process or as a garnish to get the best from their fresh flavours.
Woody herbs like thyme, rosemary and sage produce aromatic oils that store better but they still pack more punch when use fresh. Woody herbs are more commonly used in the early stages of cooking so their oils have time infuse and flavour the dish.
Growing your own herbs All herbs can be grown from seed but many of the woody herbs can be tricky to germinate so buying plants is often the better option. It is also relatively easy to propagate new plants by taking cuttings from woody herbs so once you have a plant you can use it to grow more. Soft herbs are easier to germinate and should grow well from seed. You also tend to use a lot more of the soft herbs at a time so having 2 or 3 plants on the go is handy. Sowing from seed every few weeks will ensure a constant supply throughout the season.
Growing herbs in pots As we've said most herbs don't like wet conditions so a well drained potting mix is important. You can use a good multipurpose compost but it is a good idea to improve drainage by mixing in coarse horticultural sand, perlite compost improver and/or vermiculite. For a herb potting compost that makes you look like a pro mix 6 parts multipurpose compost with 1 part perlite and 1 part vermiculite. You can also add 1/2 a litre of blood fish & bone to every 30 litres of mix to add nutrients if using a low grade compost.
With regard to pots there are a wide range of options from standard pots to troughs and more ornate herb planters; as long as it holds soil and has drainage holes you can use practically anything. As with the compost mix the most important consideration is drainage.
Terracotta is porous and has the advantage of draining well and keeping roots cool in Summer. Of course they will also dry out quicker so you need to keep a close eye on watering. Plastic pots are probably the most versatile and come in the widest range of shapes and colours. Growing herbs in metal galvanized containers has become very fashionable but make sure you line the containers before filling. Metal containers can get hot quickly and damage roots, lining the insides with several layers of newspaper will help protect them.
Pot size - As a rule of thumb pots should be at least 6 inches (15cm) in diameter and 8 inches (20cm ) deep. As regards volume around 5 litres will be sufficient for most herbs with the exception of bay or rosemary which will need a bigger pot. If you are growing a number of herbs suited to the same growing conditions it may be easier to use one large pot instead of a number of smaller ones. 1 or 2 large planters of mixed herbs with small pots placed in front will look a lot better than 10 or 15 individual pots.
When growing different herbs in the same pot avoid mixing those that like plenty of water (chives, mint, chervil and coriander) with those that prefer well drained roots (rosemary, thyme, sage, bay and oregano). Also don't plant very different size herbs in the same pot or the large ones will out compete the smaller ones. Remember there are many different varieties of each herb including compact varieties of large plants like rosemary so you should always be able to find something to suit your planting plan.
Growing Herbs Outdoors The same rules apply as with pots, it is drainage you need to watch with varieties that prefer free draining soil. If you have a heavy clay soil and a damp garden you will be better growing in raised beds for the improved drainage they provide. Frost tender herbs won't be suitable but larger plants like dill or fennel will be better planted out than in pots. Many plants like chives or borage make pretty plants in a border so can be used as edible parts of an ornamental planting plan.
Growing soft herbs The most common soft herbs include basil, coriander, chives, dill, mint and parsley. I find it easiest to start them in modular trays and then pot them on to larger pots at approx 4 weeks old. Here are a couple of tips on each one which you may find helpful:
Basil does not like being harvested hard so it is best to grow a number of plants and take a few leaves off each so as not to over stress the plant. Basil loves warmth and will grow best in a greenhouse, tunnel or sunny South West facing windowsill.
Coriander will run to seed quickly in hot weather especially if you have chosen a variety bred for seed production. If you are growing coriander for its leaves choose 'Leisure' or 'Calypso' as they will be slower to bolt.
Chives are vigourous and will grow almost anywhere. The purple 'puff ball' flowers are also edible and carry the characteristic onion flavour of the leaves. They look fantastic added whole to a salad or chopped as a garnish.
Dill is a large plant (similar to fennel) so is not really suited to growing pots. It is grown for both leaves and seeds which have an aniseed flavour more intense in the seeds.
Mint is available in a number of different types including peppermint, spearmint, chocolate mint and apple mint. They have different growth habits from creeping miniatures (corsican mint, creeping pennyroyal) to much larger plants (spearmint) so choose the right variety for the space you have. All can be invasive so best confined to their own planters or pots. To keep potted mint vigourous remove every spring and cut the root ball into quarters and re-pot in fresh compost.
Parsley must be the most used culinary herb. The most common types are traditional 'Moss Curled' and 'Italian Flat Leaf'. Any variety has a long tap root so they will like a deeper pot than you might think. Use a pot of min 20cm deep for small plants or 30cm deep if you want them to last more than a summer. Parsley also needs light to germinate so only cover with a very fine layer of compost when sowing.
Sorrel has a sour lemony taste and is great with eggs or salmon or used in a salad. It is not a herb often found in the shops so a good one to grow yourself. Originally a woodland plant so will tolerate partial shade well.
Growing woody herbs Woody herbs include Bay, Rosemary, thyme, oregano and sage. They all like the same well drained conditions so the potting mix is especially important as is taking care not to over water. Keeping plants well clipped will keep them bushy with plenty of fragrant new growth. Due to their oil content woody herbs are more suitable for drying than soft herbs as the oils retain their flavour in storage.
Bay is difficult to grow from cuttings or seed so best bought in. Bay can easily be damaged by frost or cold winds so plant in a sheltered spot or in a pot that can be moved inside in Winter.
Rosemary will not like freezing temperatures either but the plants are quite hardy and usually recover from frost damage. Common rosemary is the most hardy, the dwarf or variegated varieties are more tender and should be grown in pots and moved indoors in harsh weather.
Thyme has many varieties with common thyme having the strongest flavour. Lemon thyme has a bright citrus flavour while caraway thyme has a fragrant pine/caraway aroma. All are compact habit plants so very well suited to pots.
Oregano will survive Winter in mild areas but will do best in pots and moved indoors where is will continue to produce its characteristic aromatic leaves. Oregano is very easy to grow and tastes far better fresh than the dried shop bought version.
Sage grows into a large and attractive plant in a border with grey/green leaves and attractive blue flowers. The flavour is strong and gamey and delicious in stews and particularly good with veal or pork. It takes a long time to dry but will keep for up to a year in a closed container. If picking for drying do so before the plant flowers.
Tarragon is traditionally used with chicken or fish. It also makes a very nice tarragon vinegar for use in dressings by steeping in wine vinegar. French tarragon has a much stronger flavour than Russian tarragon which is very mild. Unfortunately you can't grow French Tarragon from seed so will need to buy plants or take a cutting from an existing plant. Cuttings are best taken in the Spring.
There are many more! I have included the most popular herbs above but there are plenty more to choose from if you get interested in these versatile plants. We stock an increasing range of about 25 herb varieties and will always be happy to help if you are looking for something in particular.
If you would like to view our herb selection please click on the link or the image below. If you would like more information on any of the plants we supply click the blue 'i' button beside each herb icon.