15 garden tips for May

May is a beautiful month to be outdoors, with all the spring flowers in full bloom and summer just around the corner. With everything bursting into growth, there’s plenty to do in the garden, and here are our top tips for gardening jobs in May.

  1. If you’ve been growing dahlia and canna tubers in pots, start hardening them off now, ready to plant out at the end of the month.
  2. Sow hardy annuals like cornflowers, Nigella and poppies for a fantastic summer display. Get the kids involved too, sowing sunflowers and nasturtiums outdoors or in pots.
  3. Sow pumpkin, courgette and French bean seeds in pots indoors, for planting out next month.
  4. Pinch out the growing tips of broad bean plants once the first beans appear. This helps reduce the risk of blackfly infestation, as they tend to gather on the succulent young shoots.
  5. Harvest rhubarb, but remember to pick only one-third of the stems on each plant, to conserve the plant’s energy for next year’s harvest.
  6. Keep on earthing up potatoes – it gives you a bigger harvest and also stops the sunlight getting to the tubers, turning them green and toxic.
  7. Get a headstart on summer by filling pots and hanging baskets with begonias, geraniums and other colourful bedding plants, but keep an eye on the weather forecast and don’t plant them out until all risk of frost is over.

    15 garden tips for May
  8. Sow basil seeds in pots on a sunny windowsill. They germinate easily, so don’t sow too thickly.
  9. Summer may be almost here but it’s never too soon to start thinking about your winter veg! Sow kale in pots in a greenhouse, and parsnips and Brussels sprouts in vegetable beds outdoors.
  10. Start hardening off tomato seedlings for planting out next month.
  11. Cut back the foliage on spring bulbs once it starts to turn yellow. Now’s a good time to lift and divide overgrown clumps of spring bulbs, while you know where they are!  
  12. Prune early-flowering (Group 1) clematis like Clematis armandii and Clematis montana once they finish flowering, to keep them from getting too big.
  13. Prune spring-flowering shrubs like forsythia once they have flowered to give them plenty of time to develop flowers for next year. Cut any flowered shoots back to strong buds lower down.

    15 garden tips for May
  14. Keep on top of weeds. Use a Dutch hoe on dry days to tackle annual weeds in borders and vegetable beds, taking care not to damage the roots of your plants. Dig out perennial weeds with a hand fork or daisy grubber. Don’t let annual weeds go to seed if you can help it – remember “one year’s seeding makes seven years’ weeding”!
  15. Mow the lawn regularly, but try to leave an area unmown this month to give pollinators and other garden wildlife a boost.

Get your garden into great shape this May with a visit to our centre. With our fantastic ranges of plants, seeds and tools, you’re sure to find everything you need!