Beans are an easy and rewarding crop to grow for summer and the best time to sow them is in the spring. This will produce early plants that will start producing a crop in summer. In temperate parts of the Northern Hemisphere this means sowing in late March or early April: in the Southern Hemisphere sowing can start in September.

It can be a mistake to start them too early outdoors in areas that get frost as this is liable to kill the seed. Meanwhile, late-winter indoors in cold climates, usually produces tall, leggy seedlings due to low light levels and too much warmth. The best time to sow beans is to wait until spring is underway will ensure there is good light to balance the warmth. And this will produce stocky plants that can be planted out when the fear of frost has passed.

Later sowings can be made directly into the ground, where the plants are to grow, when night temperatures are 5C and above. These sowings will produce beans from mid to late summer, even on into the autumn. Meantime, in warm and hot climates, beans can be sown pretty much all year round.

How do I plant beans seeds in pots?

Sowing beans in pots has the benefit of protecting the seeds from birds, mice and other pests. It also allows you to control the amount of water and warmth to encourage rapid germination. In cold, wet soil in the garden, the seeds can easily if they don’t start immediately into growth. The easiest way to sow bean seeds is into small containers of peat-free compost. I use pots made from compostable plastic or improvise with the cardboard tubes from toilet rolls or paper towels.

The biodegradable pots will usually last for a season or two and the seedlings should be knocked out of them when it comes to planting out. Meantime, the cardboard tubes will provide a home for the compost and seedlings for up to 6 weeks, by which time they should be planted out in the garden. The roots of the seedling will grow through the tubes, which will decompose in the ground.

Should I firm compost after filling pots?

Most peat-free composts benefit from being passed through a coarse garden sieve before filling the containers. This removes any coarse fibrous material. To fill the pots, I let the compost drop from between my fingers until the pot is slightly over filled. Never use your fingers to firm the compost as this can make it too compact. Instead, I use a large plant label or a short piece of timber to ‘strike off’ the excess compost level with the top of the pot. Push the straight edge into the compost in the middle of the pot and use a gentle backwards and forwards ‘sawing’ motion to scrape off the excess first to one side, and then the other. This will make sure the container is evenly filled.

Next, if using a pot, hold it firmly each side and gently tap the base onto a work surface, three times. This will consolidate the compost in the pot and cause it to settle down 4-5mm below the rim. If using cardboard tubes, set a collection of them in a seed tray or recycled supermarket punnet to retain the compost. Once all the tubes are filled, tap the whole tray or punnet on the surface to settle the compost.

Thankfully bean seeds are large enough to handle easily and sow individually. Allow 2 seeds per pot or tube as a safeguard. Hold the seed on its side, between thumb and forefinger and push it gently into the compost to twice the depth of the seed. Don’t push it in too deep as it may not germinate.

Is it best to water seeds after sowing?

Water the pots using a watering can with a fine rose attached. Start watering off to one side of the pots and, once the water is flowing out in a fine, steady spray, pass the nozzle back and forth over the compost to thoroughly soak it. This will also settle the compost around the seeds and provide enough moisture to start the rehydration process of the seed which will kick start germination.

Keep the pots in a bright position such as a windowsill or in a conservatory, greenhouse or cold frame. Ideally the bets time to sow beans is when the daytime temperature indoors is around 16-23C. By night it can be as low as 10C for French and runner beans.

Expect bean seedlings to appear in around 8-10 days in ideal conditions. Grow the young plants on in a bright place and reduce the temperature to 12-18C to encourage strong, stocky plants. Once 3 pairs of leaves have form, the growing tip can be pinched out between thumb and forefinger to encourage side shoots. This will produce more growing stems per plant and can help to increase the number beans. When planting out climbing beans, use a tripod of canes or other form of support for them to grow over.