With the tender summer veg season upon us, thoughts turn to French and runner beans. Even while pods on my sturdy little broad beans are swelling, I’m busily building stout frames for my French beans, Phaseolus vulgaris, and runners, Phaseolus coccineus.

Broad beans, dried, had long been a vital crop in Europe, both for people and livestock, and folk simply tholed the windy effect of a hearty meal. But in 17th-century France eating peas and beans fresh was the new delicacy, so the New World beans, eaten green, fitted in with this trend.

Some wild runner bean species in Central America can grow to six metres, but fortunately early farmers developed much smaller varieties with larger beans. Apart from modern dwarf varieties, runners now reach two metres.

So, when planting, you need a frame that can support heavy foliage during wet, summer gales. The plants are more secure wrapped round poles rather than growing through flimsy pea netting. And with the weight of the crop obviously at the top, a tapering wigwam can force plants to produce a tangly top-heavy mess.

Admittedly, a wigwam is very stable but you can build an equally solid structure that also meets the plants’ needs. Stick

two-metre canes or poles diagonally into the ground

25-30cm apart to form a square, circle or rectangle that has 60cm between two parallel sides. Opposing canes should cross to form an X. Securely tie the canes of square and circular structures where they meet at a central point. With more traditional rectangular frames, run horizontal canes above and below the intersecting point of each pair of opposing canes. Plant one bean for each cane or sow two beans and nip off the weaker one.

Although we lump French and runner beans together, they look, taste and act differently. Runner beans are much tougher. They naturally grow in wet cloud forests so had to develop resistance to the many fungal disorders there. French beans, on the other hand, were not toughened this way and need sheltered, warmer growing conditions.

And our changing climate has drastically affected success with beans. When I started growing them in the Scottish Borders 40 years ago, French beans were a non-starter and an early September frost could even kill my runners before many beans appeared. Now they’ll usually keep going until late October.

Climatic conditions were even worse during the 17th-century mini Ice Age. Many early runner bean introductions were day length sensitive. Even with 12 hours of daylight, they take 82 days to fruit, so the plants were frosted without setting fruit. This explains why gardeners only treated them as ornamentals: they had no choice.

But French beans are not day length sensitive, so could be forced in peach houses for a fine tasty crop. With harvesting, the general advice is to pick small, tender pods, much as we do with mange-tout peas. But the mature beans are also pretty good. Worldwide, there’s a larger Phaseolus harvest than all other legume species combined. The rest of the world ain’t mad, so don’t miss this treat.

I certainly can’t keep on top of my huge crop when the plants are in full spate, so pick small tender fruits and let the rest grow on to maturity. The plants will slow down production, but if you’re struggling to keep up, why worry?

I go a step further and have one stand of Czar beans exclusively for shelling and also let some of my Scarlet Emperors develop big beans. A few bags in the freezer over winter is invaluable.