Garden Jobs for May

May is a wonderful month in the garden. By now spring has well and truly sprung. The bluebells are swarming through the woods and the bulbs you, hopefully, planted last autumn are nodding daintily in your flower borders.

Bluebell Wood

Bluebell wood in Chew Valley, Somerset

So what are the essential garden tasks this month?


It’s not too late to lay a generous carpet of mulch on the garden, while you can still see soil between the plants. Make sure the mulch layer is nice and thick, around 3 inches or 8cm. Bark chip is easy to find and works well as a mulch. It will suppress weeds and help your soil retain moisture. Once the mulch is down, be vigilant with weeds. An hour’s weeding in May is worth several hours work later in the growing season.

If you planted any new trees or shrubs last autumn, or over the winter, make sure they don’t dry out during May. Give them a good drink, at least one watering can full, after 3 or 4 days dry weather.

Prune back vigorous spring flowering climbers like Clematis montana or Clematis armandii. These pretty climbers are tempting in the garden centre as they look good almost immediately but they quickly get out of hand, if you let them, and become a tangled mess. Always tie climbers to a framework with twine, rather than tucking them behind and under the framework. This creates a more manageable plant that won’t pull the wires or trellis off the wall in 10 years time.


Some of the plants in your garden will appreciate extra nutrition at this time of year. Not all plants need extra help but plants like roses will flower more prolifically and for longer if you give them a boost. Use an organic fertiliser such as well rotted compost or blood, fish and bone if you want to work with nature. Plants that appreciate a Spring feed include box, roses and other flowering shrubs.

Remove the spent flowers of any bulbs that have finished so the plant sends all the nutrition down to the bulb for next year’s flowers, rather than wasting it on making seed.


You don’t need a a greenhouse to grow a few plants from seed. Growing annuals is very rewarding and not that difficult. Some annuals, known as hardy annuals,  will grow happily if you sow them directly into the ground in May.  Annual flowers are very useful for giving the flower border a bit of extra froth throughout the season. They also make great cutting flowers. Flowers such as nigella, clarkia, nasturtiums, cornflowers and sunflowers will all pretty much take off if you just throw them over your shoulder onto a sunny area of the garden. Make sure you choose flowers you like, though. Once established, these flowers will self-sow and pop up in your garden every summer for years to come.