WHEN I think of runner beans my mind is cast to the long, hot and balmy days of summer - and lots of watering! Runner beans (Phaseolus coccineus) originated in South America, arriving in Europe at the end of the fifteenth century. In the wild, they grow in the Mexican mountains where they are in good company with the likes of lobelias and dahlias. Perhaps surprisingly to some, they are perennials, though in our climate are best treated as annuals. It is, however, possible to store the roots in damp compost over winter and replant the following year as normal.

Runner beans are a warm-weather crop - fast-growing and very rewarding to grow. For starters, the flavour is fantastic, especially when young succulent stringless beans are harvested and eaten the same day.

As a bonus, they also look great and will prove to be a boon to any ornamental garden. Indeed, the runner bean was first thought of as a flowering plant, that is until people discovered what a joy it is to eat. This is a crop made for the ornamental kitchen garden idea of mixing edible crops with flowers.

Runner beans, although one of the heaviest yielding crops (up to 30kg or about 65lb from a 3m or 10ft row), are not at all difficult to grow. They are, however, perhaps more weather dependant than some crops. For example, during persistent hot, dry weather the setting of flowers into beans can be a problem. Meanwhile, in cold, wet, sun-starved summers the crop will invariably sulk and perform disappointingly. Last summer proved to be less than ideal with beans cropping very late here in Yorkshire. I harvested some tasty beans in the last week of October, by far the latest I can ever recall.

Runner beans do not like very heavy and acidic soils. Lime acidic soils during late winter, allowing rain the chance to wash it in the soil. Avoid those conditions and heavy shade and you are half way to growing a good crop.

Soil preparation traditionally starts six months before you sow the seed. Some gardeners dig a trench 2ft deep and fill it with a combination of leaf mould, compost and well-rotted organic matter. If organic matter is in short supply, torn up strips of cardboard and newspapers added during winter will help.

Runner beans are deep-rooted plants and they crave sustained moisture at the roots. Dryness at the roots is one cause of flowers dropping, rather than setting. A humus-rich soil with good fertility, and moisture-retaining capability and good drainage is runner bean heaven. Additional watering with the hose will be needed in dry periods and the beans should be given a thorough soaking. It is difficult to over-water runner beans during dry weather.

Mulching is a good idea to retain that all-important moisture and to help in the inevitable fight against weeds. Mulch after transplanting while the soil is still moist. Watering is very important, particularly as the plants approach the flowering stage. Some gardeners advocate spraying the flowers every evening to aid setting. I have never found this necessary, so can't really comment on the merits or otherwise of doing this. I'd welcome readers' views.

A good tip is to align the bean row so that it runs north to south. This allows the sun to get round both sides. A runner bean row can cast heavy shade so bear this in mind when positioning near other crops. Remember, a row of thriving runner beans can make a fine attractive, albeit temporary, screen.

You may well need to tie in the young bean tendrils to encourage them to begin their climbing pursuit at the beginning. Once they get the hang of it they will romp away and wrap around the canes without any further assistance.

Cropping should begin about three months after sowing the seed. Unless you can sell or give away the surplus in return for goodwill, you will towards the end of August inevitably encounter a glut of beans. Most experts will tell you the beans can be frozen and still retain their flavour. Personally, I find them tasteless and very disappointing after freezing. I would much rather give them away.

Runner beans, as their name suggests, climb to a height that can reach 10ft in the UK in ideal conditions. As a result, site the row in a sheltered location, out of the full force of prevailing winds.

Plants typically are grown up 8ft canes or poles, made into a wigwam or used on a stand-alone basis in a row. The old technique of using two rows of canes 2ft apart and tying these at the top works very well. Several canes are then tied horizontally in the "V" formed at the top of the angled canes for a little extra strength.

They can also be grown through nets if you prefer. Perhaps having to untangle the spent foliage at the end of the season may put a dampener on this idea. I've seen runner beans grown through trellis or even clambering over arbours or rose arches where they look really effective. Or for something different try growing them through taller varieties of sweet corn, pinching out the tops of the plants when needed. A huge height will not be attained; it will, however, make an interesting talking point.

Regular picking of the beans is the key to enjoying a long harvest season. The more you pick the more you get with runner beans. It's the same principle as with sweet peas. Once the plant starts manufacturing seeds that get too large and are starting reach maturity, the job is done as far as that plant is concerned and production slows. I check my plants daily in high season, as young tender beans are the best for all round flavour and quality. It is far better to pick early to prevent the pods becoming too stringy. If you miss any pods and they become too big to use, strip them from the plant and compost.

It is not essential to let the beans grow taller than your head. There is a technique that allows the height of the plants to be kept to around 2-3 feet. This is achieved by pinching out the tips of the beans when they have reached the height of your choice. Side shoots will soon develop which will also need pinching out when they reach about six inches in length. Subsequent growth is dealt with accordingly. Pod production is arguably slightly lower, though still more than enough. This method enables the beans to be grown in a smaller space where otherwise they may not.

There are specifically dwarf bush types now that remove the need for pinching out the shoots. These reach a height of no more than 18 inches. Hestia Dwarf' is one such string less variety with decorative red and white flowers. This grows well in containers and is well worth a try if slugs are a problem. Pickwick' is perhaps the best-known bush variety and is a little earlier than Hestia'. Large containers and tubs are a great way of growing bush runner beans, though watering becomes even more critical and inevitable almost every day at the height of the season.

Frost is destructive to the half-hardy runner bean. It is vital to avoid subjecting them to frost at any point in the season. Start them off at the end of April or early May and protect them by sowing under glass and hardening off before planting out in your area when risk of frost has passed (usually end of May or early June). If you wish to gamble with slightly earlier sowings in milder areas, use fleece to provide several degrees of frost protection. When the mercury rises, the beans will be fast growing and later sowings will catch up. There is nothing to be gained by transplanting the young plants into cold sticky soil. They will sit and sulk and worse still may even rot as many did during the wet spell of last summer.

Alternatively, when the weather warms up at the end of May or early June sow directly in the soil. I like to sow two beans to one cane under fleece, removing the weaker one after several weeks. Germination typically takes 14-21 days.

Flower dropping is common in hot, dry conditions and can be combated by good soil preparation (as above).

Slugs can be a menace during wetter seasons. I've seen the tops of young plants completely devoured overnight. Blackfly and red spider mite can attack, but in healthy plants they are rarely a problem and are barely worth a mention.

The shelf life of runner bean seed is relatively low. It may remain viable for two seasons, then it will be time to bring in replacement seed.

The variety Painted Lady' was introduced to the UK in 1633. The very fact that it is still around today and as popular as ever, says it all. This is a really attractive variety with red and white flowers that are more attractive than the common scarlet red flowering varieties. This is one of the varieties to grow in your front flower garden.

Scarlet Emperor' is my favourite variety for pure unadulterated flavour alone. Popular since the 1890s this is a reliable good doer in the north of England.

Streamline' is widely available in most seed catalogues and garden centres. The flavour I found not quite as good as Scarlet Emperor'. Even so this variety is dependable and heavy cropping.

White Lady' is the one to go for if you want a bean with white flowers! The flavour is good and the plants look great.

  • Email Lee with any horticultural question at leeseniorgardening@yahoo.co.uk.