What to sow and grow in May

Sow poppies to attract pollinators
Image: Poppy 'Cherry Glow' from Thompson & Morgan

May is here at last. The weather is warmer and sunnier, the days are getting longer and summer is definitely on its way.

For more information about other gardening jobs to start in May, read our helpful companion guide today, or check out our top picks to keep you busy sowing and growing this month:

Flowers to sow and grow in May

If want a dazzling display this year, start larkspur off in pots.
Image: Larkspur 'The Seven Dwarves' from Thompson & Morgan

In the greenhouse / indoors

• Start larkspur (Consolida ajacis) off in pots — try larkspur ‘T&M Improved’. This annual has similar flowers to delphinium, but is much easier to grow.
• Sow helipterum indoors — they make excellent dried flowers.
• Start salvia off indoors this month or buy garden ready plants to brighten up your summer bedding. Try Salvia patens 'Blue Angel' for fashionable cobalt flowers.
• Start to sow biennials like foxgloves, dianthus plants and wallflowers in seed trays, for flowering next year.
• Sow perennials, like delphiniums, lupins, aquilegia and primula, in seed trays for flowering next year and in the years to come. For more perennial growing advice, visit our hub page.
• Plant up pots and baskets of summer bedding plants and harden off before placing in position. In cold areas wait until June to do this. Try begonia x tuberhybrida 'Apricot Shades Improved' F1 Hybrid in containers for gorgeous peach flowers. For more information, read our 'Perennial Plants for Pots' article.
• Plant up certain varieties of climbing perennials, like Passion Flowers, in a sheltered, warm spot - such as a conservatory or greenhouse, or at the foot of a south-facing wall.

Direct sow outdoors

• Direct sow sunflower seeds now.
• Sow nasturtium seeds now, either under cover in pots or directly outdoors in your borders and containers.
• Direct sow poppy seeds, cornflowers and scabious to attract bees and butterflies into your garden. Read how to encourage wildlife to your garden and give nature a helping hand. Try a pre-mixed wildflower mixture for nectar rich flowers perfect for pollinators, or browse the RHS Perfect for Pollinators Bedding collection for more inspiration.
• Direct sow ground cover annuals like phlox or candytuft now the risk of frost has passed.
• Try direct sowing godetia 'Little Frills Mix'(Clarkia amoena) for easy colour in your flower beds this summer.
• Direct sow candytuft ‘Dwarf Fairy’ (Iberis umbellata) around the edge of your beds to add a touch of pink.
• Direct sow poached egg plants (Limnanthes douglasii) to bring beneficial insects into your garden and vegetable plot.
• Try growing purple toadflax (Linaria purpurea) to fill beds and borders with vibrant colour.
• Direct sow Nigella damascena ‘Moody Blues’ — this variety has attractive double flowers and freely self seeds.
• Towards the end of the month, direct sow patio plants in containers. Try Gazania 'Tiger Stripes' for a dramatic pop of colour.

Plant outdoors

• Plant scented annuals, such as marigolds or snapdragons, now the risk of frost has passed. Visit our comprehensive hub page for expert advice on bedding plants, and learn how to make your beds & borders look great across the season.
• Plant up foliage bedding varieties to allow them to establish over summer.
• Plant out climbing annuals, such as Sweet Pea 'Sweet Infusion' and Petunia 'Tidal Wave Improved'.
• Now the ground's warmed up, it's time to plant out of patio shrubs and perennial patio plants, such as lavender and geraniums.
• You've still got time to plant certain scented bedding plants to fill gaps. Try Alyssum 'Alice Golf Mixed' which looks great in beds, and is also loved by pollinators!
• Plant hydrangea plants in any rich, fertile soil.
• Plant out pollinator-friendly annuals now to create a mini wildlife patch in your garden. Try Rudbeckia 'Enchanted Embers' for a rich tapestry of colour that will last all summer, or visit the RHS Perfect for Pollinators Annuals collection for more inspiration & varieties.

Herbs & vegetables to sow and grow in May

Start cucumbers off in module trays this May
Image: Tortoon

In the greenhouse / indoors

• Start off sweetcorn in modules ready for planting out once all risk of frost has passed - Try supersweet sweetcorn ‘Summer Glow’ and grow at least 12 plants for good pollination and cropping.
• Sow basil in pots for the greenhouse or patio - this Mediterranean staple thrives in warm conditions.
• Sow pumpkin, squash and courgette seeds undercover now.
• Try sowing lettuce in module trays under glass for transplanting into the garden later. Sow every 3 or 4 weeks for continuous harvesting — try lettuce ’All The Year Round’ for reliable cropping.
• Sow cucumber and gherkin seeds in individual pots or modules.
• Sow runner beans and french beans undercover, sowing individually into module trays for planting out after the risk of frost has passed.
• Start brassica and leafy green seeds under cover now — yes, it really is time to think ahead to winter cropping!
• Sow perennial herb seeds, such as rosemary, sage, thyme ‘Old English’, lovage and lemon balm under cover.
• Plant glasshouse tomato plants in beds or growing bags. Find more helpful information and advice about growing tomatoes over at our hub page.

Direct sow outdoors

• Direct sow borage and use the flowers for garnishing salads and desserts.
• Try sowing comfrey seeds in a neglected corner of the garden — it can be used to make fertiliser or for mulching, and is a rich source of nutrients. Direct sow or sow into seed trays indoors.
• Sow beetroot and chard seeds thinly, directly into the ground.
• Sow broccoli and calabrese in a nursery bed for transplanting later on, or sow directly in your vegetable plot.
• Direct sow brassica and leafy green seeds like cabbage and Brussels sprouts. Net them early on to prevent cabbage-white butterflies laying their eggs on the leaves.
• Direct sow carrot seeds in rows and protect with horticultural fleece or enviromesh to prevent carrot-fly attack.
• Sow red chicory radicchio 'Rossa di Treviso precoce' directly into the soil for colourful flavoursome salad leaves.
• Sow chive, coriander, dill and parsley ‘Laura’ seeds directly into the ground or in containers.
• Try growing hardy Lamb's Lettuce ‘Favor’ outdoors, for summer and winter salad leaves with ‘nutty’ flavour.
• Direct sow kohl rabi 'Kolibri' F1 Hybrid — it will be ready in as little as 8 weeks.
• Sow peas directly into the ground, or start them off in modules if mice are a problem.
• Try direct sowing nutritious pak choi ‘Tricolour Mix’, sow seeds every 3 weeks for a continuous crop.
• Direct sow your parsnip seeds now. Sow 3 or 4 seeds every 20 cm and thin to the strongest plant.
• Sow radish seeds directly into the soil for a quick and easy home-grown salad - try Chinese radish 'Mooli Kumbong' F1 in containers for flavoursome white roots.
• Sow salad leaves directly into the ground or in containers.
• Start cauliflower ‘All The Year Round’ seeds under cover.
• Sow perpetual spinach seeds in soil enriched with plenty of organic matter for prolific cropping and resistance to bolting in dry soils.
• Sow spring onion seeds in drills outdoors for a quick crop to flavour salads and stir fries.
• Try Swiss chard sown outdoors for a colourful crop — it even looks great in flower beds!
• Sow swede seeds outdoors in a rich, fertile soil for autumn and winter crops - Try British bred swede ‘Tweed’.
• Start to sow turnips now for a great addition to casseroles and stews - Try turnip ‘Golden Ball’ for attractive golden flesh.
• Grow your own watercress in containers, making sure the container is sitting in 2-3 inches of water at all times.

Plant outdoors

It's time to plant leeks out to their final position.
Image: Shutterstock

• Plant out brassicas and leeks to their final positions.

Fruit to sow and grow in May

Sow Melon seeds now for juicy summer harvests.
Image: Melon 'Outdoor Wonder' F1 Hybrid from Thompson & Morgan

In the greenhouse / indoors

• Sow melons in individual modules now — for the best crops, try growing a variety suited to the British climate, such as 'Outdoor Wonder' F1 Hybrid. For more information about growing your own fruit, check out our hub page.

Keep one step ahead — what to order in May

Order tomato plug plants now to pot on and harden off after the last frosts.
Image: Tomato 'Sungold' from Thompson & Morgan

• Order pea and bean plants.
• Buy spinach 'Perpetual' seeds to sow next month for successional cropping.
• Order tomato plants as postiplugs or potted plants.
• Order pondside perennials for planting out next month.