Published: 29 April 2025

It’s May – Springtime! This is when the UK’s growing season really gets going. It’s arguably one of the most exciting months in the gardening calendar. At least until harvest time, anyway. With the soil warming up, longer days, and the risk of frost largely behind us, it’s time to pull your wellies on and get digging, sowing, and growing. The big question is – where should you start?

The Best Flowers, Veg, and Herbs to Plant in May

Flowers to sow or plant in May

When it comes to flowers, you’re really spoilt for choice in May. All of the most-loved garden annuals are ready for direct sowing. And the seeds you may have sown early to get ahead of the game – sweet peas, antirrhinums (technically a perennial, but treated as an annual), larkspur – should be set for hardening off and planting out.

Some of our favourite flowers for direct sowing now are:

  •  Sunflowers
  • Calendula
  • Cosmos
  • Nigella (Love-in-the-Mist)
  • Cornflowers
  • Poppies
  •  Nasturtiums

Pro tip: Watch for late frosts, bring in any tender plants on cooler nights, and don’t forget to harden off before planting out.

Vegetables to sow or plant in May

When it comes to vegetables, May is THE growing month. There are so many different varieties ready for direct, outdoor sowing, planting out, or sowing under glass that it’s hard to choose where to start.

Direct sowing:

  • Carrots
  • Beetroot
  • Lettuce and salad crops – Sow a fresh batch every couple of weeks for a continuous harvest
  • Spring onions

Plant out when the soil is warm:

  • French and runner beans
  • Courgettes, squash, and pumpkins
  • Sweetcorn
  • Peas

Sow under cover:

  •  Cucumbers

Plant under cover:

  • Tomatoes
  • Chillies
  • Aubergines

Pro tip: Don’t forget to space your veg properly. When planted too closely, vegetables won’t reach their full potential. So, read the instructions on the packet and plant carefully. Thin out overplanted areas.

Pro tip: Remember to companion plant. Placing the right plants in the same beds can help ward off pests. Onion, garlic, and leeks can deter carrot fly. Nasturtiums attract aphids away from beans. Basil deters white fly. Sage repels cabbage moths. And calendula draws pests away from crops while attracting pollinators.

Herbs

If you already have perennial or evergreen herbs in place, they’ll be going wild about now. Mint, thyme, oregano, chives, and rosemary should already have put on a spurt of fresh growth. While sorrel will be making a comeback. If the clumps are large and established or beginning to look dead in the middle, now is a great time to divide your herbs.

You can also supplement your herb collection with annuals, such as basil, borage, and fennel. But keep them indoors until all chance of frost has passed.

Herbs to sow now:

  • Basil (undercover)
  • Coriander
  • Borage
  • Dill
  • Parsley
  • Chives
  • Mint
  • Sage (undercover)
  • Thyme (undercover)
  • Lemon balm (undercover)
  • Rosemary (undercover)

May is always an amazing time in the garden. This year in particular, the kind weather means that we’ve been spoilt with the most incredible blossom. But now it’s our turn to add to nature’s glories with some wonderful Spring planting. What’s on your ‘to sow’ list?Plan your visit to Holker Hall & Gardens this Spring.

Pro tip: Always keep mint in pots. If you plant it out in a main bed, it will quickly take over.