• Grow annuals and flowering herbs which encourage beneficial insects into your garden.
• Soil that has been flooded in previous months will be compacted. If it has dried out sufficiently, aerate the soil by spiking deeply with a garden fork, but take care not to damage surviving plants or their roots.
• Keep your eyes open for pests and diseases in the greenhouse and the garden, and take appropriate action immediately to stop the problem getting out of hand.
• Weed regularly.
• If the weather is dry be prepared to water new plants, seedlings and other vulnerable plants.
  Be ready to protect young and vulnerable plants if frost is forecast.
• Ventilate the greenhouse and apply shade paint towards the end of the month, and damp down if the weather is hot

Lawns

• Sow a new lawn early in the month if not done in April.
  
• For established lawns you can progressively lower the mower blade.
  
• Trim lawn edges each time you mow.
  
• If not done last month, re-cut and repair ragged edges.
  
• Apply a spring lawn fertiliser and, if necessary, a weedkiller to established lawns.
• Alternatively treat weeds individually with a spot weeder or dig them out with an old knife.
  
• Remove any coarse grasses by hand.

Ponds

• Finish planting and replanting aquatic plants.
  
• Skim off algae

Annuals and biennials

• Make a final sowing of hardy annuals, including candytuft, clarkia, cornflowers, ornamental grasses, larkspur, love-in-the-mist, night-scented stocks and mignonette.
  
• Plant out sweet peas, if not done in April.
  
• Support tall-growing hardy annuals.
  
• Begin to harden off half-hardy annuals and bedding plants previously sown under glass.
  
• In milder areas plant half-hardy annuals and bedding plants towards the end of the month.
  
• Sow biennials in nursery rows
  
• Plant out seedlings of Foxglove, Sweet William, Forget-Me-Not, Wallflower, Polyanthus
  
• Do not plant out any tender species until hawthorn and laburnum are blooming

Perennials

• Put plant supports and stakes in position.
  
• Remove weak new shoots from dense-growing perennials, such as phlox.
  
• In colder areas plant new perennials and cut back evergreen ornamental grasses.
  
• Sow new perennials in nursery rows.
  Finish planting out early-flowering chrysanthemums.
  
• Lift and divide spring-flowering perennials as necessary, and trim off dead, straggly growth.
• Revitalise aubrieta, gold dust and similar vigorous spring-flowering rock plants by cutting them back hard.

Bulbs

• Allow foliage of spring-flowering bulbs to die down naturally; lift and heel them in, in an out-of-the-way corner if you need the space.
• Stake tall-growing lilies
  
• Dead-head spent daffodils. Remove the seed pod and the old petals.

Roses

• Spring feed bush and climbing roses.

• Check tree ties.
  
• Check mulches and replace if necessary.
  
• Trim hedges after checking for wildlife.
  
• Feed container-grown shrubs and perennials
  
• Prune back the branches of fig trees. Rub compost into the cut to prevent bleeding
  
• Clip bay trees
  
• Hang out pheromone traps to prevent apples being ruined by tunnelling larvae.
• Stifle side-shoots of raspberries with pruning, and water all soft-fruit bushes and fruit trees.
• Prune grape vines to encourage better setting of fruit.

Herbs

• Sow new herbs such as coriander, dill and parsley in situ.
  
• Sow basil under cover
  
• Take cuttings of rosemary, sage and thyme. Make them 10cm long and put them in gritty compost in a sheltered, well-lit spot in the garden.
  

• Erect supports for runner beans and climbing French beans. Make sure they will not cast shade over plants that like the sun.
  
• Sow beetroot, cabbage, carrots, kale, parsnips, peas, radish
• Begin earthing up potato plants.
• Pinch out the tops of broad beans to discourage blackfly attack.
  
• Protect roots of brassicas against cabbage root fly with artificial barriers such as card collars.
• Plant out celeriac, celery, sweetcorn, runner beans and other strong plants grown under glass. Mulch well.
• Protect carrots against carrot fly with two-foot barriers of fine netting or clear polythene.
• Plant fruiting vegetables under cloches.