In an extract from Grow Fruit and Vegetables in Pots by Aaron Bertelsen (Phaidon), the author walks us through the wonderful world of plants that do not allow any limitation of garden pots to stop them from flourishing.
How to Grow Potted Basil
Basil is ideally suited to being grown in a pot. To thrive, it needs as much heat and sun as you can give it, so move the pot around to keep it in the perfect spot as the summer progresses and the sun gets higher. Heat will concentrate the oils in the plant, intensifying the flavour and also scenting the air around it with the smell of a Mediterranean summer. Water it every couple of days. Basil is best eaten raw, torn up and sprinkled over tomatoes, grilled (broiled) vegetables or pasta, with nothing more than a little good olive oil. A word of warning, though: make sure you buy your pot of basil from a garden centre or nursery, not the supermarket. Those pots might look healthy, but the plants in there are overgrown and congested, and they will not survive being planted out.
Favourite varieties
‘Sweet Genovese’ is a great variety for the kitchen, with intense flavour and aroma. It also seems to do very well in a pot.
Key dates
There is no point sowing basil too early. It needs warmth and reasonably dry weather to really get going, so wait until mid-spring. If you prefer to buy seedlings, note the warning above about those supermarket pots.
Common problems
Basil will struggle in a cool, damp summer. I have known seasons when I have had to give up on it altogether. If it’s really flagging, try bringing it inside and putting it on the windowsill. The extra heat might just give it a boost and get it moving again. If that does the trick, put it back outside. Damp conditions can also cause mildew. Once your plants have it – look out for sickly yellow leaves, possibly with black spots – there is no choice but to pull them up and bin them (don’t put them in your compost bin, if you have one, as the spores can spread). The best way to prevent mildew is to allow space between plants for air to circulate, and water from the base to avoid wetting the leaves.
How to Grow Potted Thyme
Like rosemary, thyme will do very well in a pot. Think shallow dishes and troughs, where the water can easily drain away, and make sure you add some sand or horticultural grit to the soil. Water and feed it well after pruning, and fresh new growth will soon appear. The rest of the time water sparingly – once a week is fine.
This perennial herb is a wonderful ground- cover plant, so put it where you are going to brush against it, releasing the scent. Alternatively, plant it around the base of a fruit tree: this will increase your growing space, suppress weeds and help to retain moisture in the soil. You can grow thyme from seed – something that I will be experimenting with soon – but if you want to get your hands on some fairly quickly, buy thyme plants from a garden centre.
Thyme offers a wide variety of flower and foliage colours. In the past I have put plants of different leaf colours – say silver, deep green and golden – together in a single large pot to create a mosaic effect, which was most effective. To add to its virtues, thyme is one of the best plants for attracting bees to your container garden. Of course, it is also extremely useful in the kitchen. I use it in soups and stews, and I love to use it in Creamed Chicken. But it is perhaps best added to dishes that are being roasted, grilled (broiled) or even barbecued because the intense heat will bring out the oils and maximise the flavour.
Favourite varieties
Make sure you are buying culinary rather than ornamental thyme. Thymus vulgaris or common thyme is the default variety. Beyond this, there is a huge range of cultivars to choose from. Go for the leaf and flower colour that appeals to you. I also like to grow lemon thyme, but it has a completely different flavour from common thyme, so should not be regarded as a substitute.
Key dates
As with rosemary, young plants need a chance to establish themselves before the cold comes, so get them planted up as soon as the frosts have passed. Prune thyme in summer, after flowering, to stop it getting too woody.
Common problems
Thyme hates to get its feet wet, and will rot off in the winter if it sits in water. To avoid this, use a good, free-draining compost (potting soil) with some added grit or sand and put the plant in a shallow pot.
How to Grow Potted Dill
With its feathery leaves and bright yellow, umbel-shaped flowers floating above the other crops, dill is great for adding visual interest to the container herb garden. Try putting a pot or two of this perennial herb among your lettuces, both for the visual effect and to cast a little dappled shade. I grow dill both for its leaves – wonderful as a stuffing or in a sauce for salmon or trout, with new potatoes, or just raw in a salad – and its seeds. These are delicious in a salad, or stirred into good olive oil and eaten with some fresh bread. Dill does best from direct sowing, as it does not like its roots disturbed. It will thrive in a pot, provided you water every couple of days and do not let it dry out. Otherwise, you will find you have a good crop of seeds rather earlier than you might have liked.
Favourite varieties
I grow Anethum graveolens for its beautiful leaves, which look rather like those of fennel. For a good crop of decent-size seeds, I like ‘Mammoth’, which also does very well as a cut flower.
Key dates
Direct sow in early spring. Cover the soil surface with fleece to get the seeds going. You can start picking once the plants are about 15 cm/6 inches tall and have a decent amount of leaves on them. Every month, pop a few more seeds into the spaces in the pot to ensure a continuous supply.
Common problems
Dill is prone to damping-off, or going mouldy. The key to avoiding this is not to stint on watering, but rather to add some sharp sand to the soil before planting and make sure the pot is in a sunny spot. Also give each plant enough space for air to circulate around it; 5–10 cm/2–4 inches is perfect.
How to Grow Potted Mint
Mint is an invasive perennial plant, with a great mat of roots. This makes it ideal for growing in pots, where it can be kept in check. Choose a big pot, 30 cm/12 inches across, as this is a vigorous plant. It is not worth growing mint from seed because it would take a long time to grow a decent-size plant. Plug plants are widely available and cheap, and you only need one. Just buy a pot from a garden centre or nursery – not the supermarket – when you see one for sale in the spring. You should only need to buy it once as mint is incredibly easy to propagate. Just cut short lengths of root – say, 5 cm/2 inches or so – lay them in a tray of compost (potting soil), cover thinly, keep moist and wait for the new growth to appear.
Every spring, I give the plant a good tidying, first removing any growth, then tipping it out of the pot and thinning the roots before repotting, top-dressing with organic matter and giving it a good feed with blood, fish and bone meal (see page 231). It then gets another haircut in mid-summer, the only remedy for the mildew that will inevitably afflict it at some point. Regular picking will help to avoid this by encouraging the plant to put on more growth. Water daily. Mint is a vigorous plant and will quickly run to seed if it gets stressed. Young leaves taste the best and are perfect for mojitos. Mint is also a brilliant partner for anything involving peas or salad potatoes.
Favourite varieties
Mentha spicata, or common garden mint, is the one I grow. If you have a friend with a healthy plant, ask if you can have a bit of it in the spring. Mine came from my friend Laura Gatacre, and I am convinced it is less prone to mildew than plants I have had in the past.