In May, all risk of frost has passed in most regions of the UK. Many vegetable, herb and flower seeds can be directly sown outdoors, while earlier sowings can now be planted out after a period of acclimatisation (hardening off) to outside conditions.
Plenty of seeds can be sown indoors, too, including more tender crops like cucumber and melon. Sowing indoors will protect young plants from slugs and snails – by planting them outside when they’re large enough to handle you’ll give them a head start on predators.
Pot-grown fruit trees and shrubs, including figs, citrus trees and gooseberries can be planted all year round, while May is your last opportunity to plant strawberry runners for a chance of a crop this year.
Find more vegetables, herbs, flowers and fruit to plant in May, below.
Vegetables to plant in May
If you’re new to growing vegetables, beetroot is a good, easy-to-grow option. The seeds don’t need much encouragement to germinate and they require little maintenance once established. Beetroot ‘Boltardy’ is one of the most popular cultivars to grow, but you could also try a more unusually coloured cultivar, such as ‘Touchstone Gold’. Sow seeds direct in shallow drills or pots. Now’s also the time to plant out pre-sown beetroot plugs outside – make sure you plant them before the roots develop or they will develop unusual shapes.
May is the last time to sow sweetcorn, to give the plants plenty of time to grow and ripen. For best results, sow in a multi-celled tray indoors and plant out when the seedlings are large enough to handle. Any sweetcorn plants sown in April can be planted out now, after a period of hardening off.
Cucumbers do best in a greenhouse but some newer varieties have been bred to tolerate outside conditions. Sow into multi-celled seed trays or individual pots and pot on when seedlings are large enough to handle.
An extremely robust crop, sprouting broccoli produces nutrient-packed, succulent spears, which are perfect for steaming, boiling and grilling. It’s easy to grow, and if you grow different varieties, you can harvest broccoli spears throughout winter and into spring. Sow into seed trays or small pots and pot on until they’re ready to plant out.
Carrots are a fantastic, easy-to-grow crop to raise from seed. As well as the classic orange cultivars, you could also try growing colourful cultivars such as ‘Yellowstone’. Sow into shallow drills of well-prepared, stone-free soil, or in pots.
Courgettes can be direct-sown in well-prepared soil outside or in pots or multi-celled trays for transplanting later on. They also work well in containers. Plants sown last month can also be planted out now, once acclimatised. Protect young plants from slugs and snails and water regularly. Courgettes are hungry crops – feed them weekly once they’ve started flowering.
Rocket is a quick-growing crop that takes up little space. Perfect for pots, direct-sow seeds on the surface of moist, multi-purpose compost and protect emerging seedlings from slugs and snails. Make regular sowings every few weeks for a continuous crop throughout summer, and harvest as and when you need to.
French and runner beans
French beans and runner beans can be sown direct outside now – dwarf French cultivars are suitable for growing in pots. Support climbing beans with a teepee of canes. Any beans sown in pots or multi-celled trays last month can be planted out now after a period of hardening off – do protect young plants from slugs and snails.
- How to grow French beans
- How to grow runner beans
- Buy runner beans from Thompson & Morgan
- Buy French beans from Suttons
Basil will grow outside but does best in heat and sunshine, making it perfect for sowing in May and keeping indoors, either on a windowsill or in a greenhouse. Sow direct in pots or in seed trays to transplant later.
Kohlrabi is a weird-looking but delicious vegetable that’s not widely grown. It’s quick-growing and reaches maturity in just a couple of months. Pale green or choose a purple variety for its stunning colour. Sow like other brassicas and harvest when no bigger than a tennis ball.
Flowers to plant in May
This airy annual not only looks good, but you can also use the anise-flavoured leaves for cooking. A brilliant plant for wildlife, it’s particularly popular with hoverflies. Direct sow dill now for summer blooms.
Sunflower seeds can be sown direct outside now, or into pots or multi-celled trays for planting out later. Try growing monster cultivars like ‘American Giant’, or shorter varieties such as ‘Moulin Rouge’ for cut flower arrangements. Protect young plants from slugs and snails, you may need to stake particularly tall varieties.
In shades of purple, pink and blue, scabious flowers are a real magnet for butterflies. Some are hardy perennials, such as Scabiosa columbaria ‘Butterfly Blue’, while tender species like Scabiosa atropurpurea are usually grown as annuals. So in small pots or seed trays to pot on and eventually transplant outside as young plants.
Native to Mexico, zinnias can be sown outdoors in May. Simply scatter seed over moist, well-prepared soil and cover with a thin layer of compost. Zinnias also work well in pots.
Bishop’s flower, Ammi majus, is pretty annual, growing to around 1m in height. More delicate than cow parsley, its blooms are popular with pollinators such as hoverflies. Try growing with other summer flowers like salvias, cornflowers and echinaceas.
Verbena bonariensis seeds can be sown directly in well-prepared, moist soil from May, in full sun to partial shade.
Nasturtiums are versatile plants for filling gaps in the border or growing in pots. Trailing varieties can be trained up a trellis or allowed to trail over the sides of containers. The leaves and flowers can be eaten, imparting a peppery kick, and you can pickle the fresh seeds for a homegrown version of capers. Or just leave them for their ornamental value. Sow direct outside or in seed trays to transplant later.
Fruit to plant in May
Strawberry runners can be planted outside now, and if you keep them well watered in the coming weeks you should get a small harvest, especially from ever-bearing varieties, which fruit over a longer season.
Pot-grown gooseberries can be planted in May, but bear in mind that the plant may be flowering at this time, so you’ll need to water it regularly to ensure the crop doesn’t fail. In dry conditions, it may be best to remove any flowers and let the plant focus on becoming established, instead. After planting, mulch around the base with home-made compost to conserve moisture in the soil.