15 Garden Tips for May

15 Garden Tips for May

May is a beautiful month to be out in the garden, with birds singing, bees buzzing and everything coming into bloom. Here are our top gardening tips for May to get your garden looking great for the summer.

Top gardening tips for May

  1. If you have summer bulbs like dahlias and cannas growing in pots in your greenhouse, start hardening them off by putting them outside during the day and bringing them back inside at night time. 

  2. In mild areas, plant up pots and hanging baskets with colourful summer bedding.

  3. Start sowing seeds outdoors for summer colour, including sunflowers, nasturtiums, poppies and cornflowers.

  4. Once spring-flowering shrubs like forsythia and Japanese quince have finished, prune them to keep them to a neat shape. Prune spring-flowering Clematis Montana if necessary to keep it to size. Tie in climbers like honeysuckle and clematis into supports as they grow.

  5. Sow courgettes, runner beans and French beans in modules or individual pots undercover. They’ll be ready to plant out in a few weeks.

  6. Keep earthing up potatoes for heavier harvests, stop light getting to the tubers, and turn them green and poisonous. There’s still time to plant seed potatoes this month too. 

  7. Sow basil seeds now in pots in a greenhouse or on a warm, sunny windowsill, ready for planting outdoors next month.

  8. For a regular supply of leaves for delicious summer salads, sow lettuce, and other salad leaves every couple of weeks.

  9. You can plant tomato plants in greenhouse beds or grow bags now, but wait until the night-time temperature is reliably above 12°C (54°F) to plant tomatoes outdoors. Remember to harden off outdoor-grown tomatoes before planting them.

  10. Slugs and snails are active now, so go on a slug and snail hunt in the evenings, armed with a torch and a bucket to collect them. Or protect your plants with slug traps or environmentally-friendly slug pellets. 

  11. Water container plants regularly during dry periods and feed flowering plants like geraniums and petunias fortnightly with a high potash feed (tomato feed is ideal). 

  12. Once tulip, daffodil and bluebell foliage has died back, cut it down to ground level. Now’s a good time to lift and divide spring bulbs to encourage them to spread.

  13. Install a rainwater butt to save water and water in the mornings or evenings to reduce water loss through evaporation. 

  14. Trim hedges, but check for nests first - remember that it’s illegal to disturb nesting birds. 

  15. As the lawn starts to grow, mow regularly to keep it looking neat, and trim border edges with edging shears.