15 Gardening Tips for May

Published on May 3, 2022

May’s a beautiful month to get out into the garden, with spring in full bloom and everything bursting back into life. Here are our 15 gardening tips for May to get your garden looking its best for summer.

May's 15 Gardening Tips

Plant summer bedding in pots, window boxes, and hanging baskets to add instant colour to patios and front steps. In colder areas of the country, wait until the end of the month to avoid any last cold snaps.
Once the leaves of spring bulbs, like daffodils, bluebells, and tulips, have died back, cut them off at ground level. Lift and divide overgrown clumps of spring bulbs.
Sow annuals like sunflowers, poppies, and cornflowers outdoors for a fantastic summer display.
Sow courgettes, runner beans, and French beans in pots in a greenhouse or on a sunny windowsill for planting out next month.
Earth up potatoes to keep the tubers covered – if they are exposed to sunlight, they will turn green and become toxic. Plant them this month if you still have any main crop seed potatoes.
Pot your tomato seedlings into larger pots, but wait until the end of the month to plant tomatoes outdoors, and remember to harden them off first.
Sow basil seeds in pots on a sunny windowsill for a constant supply of tasty leaves all through summer. You can also sow coriander outdoors now.
Sow a new batch of salad leaves every couple of weeks for fresh salads throughout summer.
It’s not too soon to start sowing your winter vegetables! Sow kale in pots in the greenhouse and parsnips and Brussels sprouts directly outdoors where they are to grow.
Make the best use of your water by watering plants in the early mornings or the evenings, constantly watering the earth, not the foliage. Install a water butt to collect rainwater and use this for watering – it’s perfect for plants.
Keep on top of weeds, especially in the vegetable garden. Run a Dutch hoe over the ground to clear annual weeds on dry days. Perennial weeds with long taproots, like docks and dandelions, can be tackled with a hand fork or dandelion grubber.
Take care when trimming hedges – always check that there are no birds nesting in the hedge before you start cutting. Remember, it’s illegal to disturb nesting birds.
Once they've finished flowering, prune spring-flowering shrubs like forsythia, Japanese quince, flowering currants, and choisya to keep them looking neat.
Now that the frosts are over, it’s time to prune Group 1 Clematis, like Clematis montana and Clematis armandii that flower early in the year. Cut back as needed to keep them to size.
Water container plants regularly even if it rains, as their foliage often stops the rainwater from reaching the compost. Feed them fortnightly with a balanced liquid feed.