Things To Do in the May Garden
Wrap up warm
It is tempting to plant out tender tomatoes, courgettes and summer bedding as soon as the weather warms. Morning Glory will show its distaste with withered, whitened foliage, and hot-house impatiens will sulk. Acclimatise plants that have been grown inside or have come direct from the nursery. Protect them close to the house for a week. A layer of horticultural fleece can be effective if the weather turns cold.
Bean and gone
Do not plant runner beans or French beans until the end of the month. They will reward you by racing away if you can exercise patience.
Playing the tubers
Dahlia tubers and canna roots can be planted safely now. By the time they are up, their tender tops should be free of frost. Soak tubers overnight if they are looking withered after winter storage and remember they appreciate some muck or compost.
As soon as potatoes break through, earth them up. Coving up the foliage in an inverted trench may seem like rough treatment, but their tops will recover quickly – and keep the fleece handy. They need moisture, so water (wisely) if we have a dry period.
Growth is exponential, so continue zero tolerance on weeds until the ground covering foliage of perennials closes over to suppress seedlings. Little and often takes the monotony out of weeding, so set a half hour aside every time you garden.
Wade into the beds while you still can and stake anything that will need it later. Later-flowering perennials that are prone to sprawling can be given the "Chelsea chop" in the middle of the month by removing the top third with shears. Though herbaceous clematis, asters, helenium, rudbeckia and bergamot may look stark for a week, re-branching will quickly form stockier plants. Pinch out spring-sown broad beans at about the same time.
Peas please me
Pea sticks (hazel brush if you can get it) are the best support for sweet pea and peas, as they will find their way naturally into the cage of twiggery. Tie in regularly, otherwise their tendrils will not get purchase if you are climbing them up bamboos.
Tie in new growth on summer-flowering clematis to extend its range, or to train it where you need it to be while it is still young and malleable. Every few years, older plants of spring-flowering C montana or C macropetala can be cut hard back as soon as the flowers fade.
Mind the sap
Sap flooding into the limbs of newly planted trees will expand their girth during this period of rapid growth. Inspect tree ties and loosen to prevent restriction.
Shoots and leaves
Make a note of when bulbs finish flowering and never remove their foliage until five weeks after the blooms fade, as they need it to replenish resources.
Daffodil clear out
Overcrowded daffodils will flower less reliably. Now is an ideal time to lift, divide and re-plant.
Thin direct sowings of hardy annuals so they don't congest each other and sow gaps with nasturtiums, eschscholzia or Nigella. Sow wallflowers between now and July in a row in the vegetable garden to lift at the end of the season.
Sow salad crops, beetroot and coriander in succession, and use the space between the tripods of beans for rocket and fast-growing mustards.
Read the article on The Observer website
Photograph: Jason Ingram for The Observer