Flowers

• Prune spring shrubs, such as forsythia and chaenomeles, after flowering to keep them compact
• Plant out dahlia tubers and cannas after all risk of frost has passed
• Tie in the new shoots of climbing plants, including clematis, wisteria and honeysuckle, to their supports
• Continue sowing annuals, such as California poppies, into gaps in borders for colour from August into autumn
• Plant up hanging baskets, but keep in a greenhouse or porch for a few weeks to establish, before putting outside
• Apply liquid feed to tulips, daffodils and other spring bulbs to encourage a good display next year
• Plant out summer bedding and tender annuals, including sunflowers, cosmos and nasturtiums, after the last frost
• Remove faded spring bedding, such as wallflowers and forget-me-nots, and add to your compost bin
• Check lilies and fritillaries for scarlet lily beetles and their larvae, as they can rapidly strip plants of all foliage
• Harden off tender plants raised indoors, but bring them back in at night to protect from late frosts
• Pinch out the shoot tips of bedding plants and young annuals, such as fuchsias, to encourage bushier growth
• Add interest to shady borders by planting a selection of hostas and ferns

How to grow hostas in pots or borders.

Fruit and veg

• Earth up potatoes, covering the shoots with soil as they appear
• Sow sweetcorn in deep pots, so the young plants are ready to transplant into the garden in June
• Reduce snail populations by going on regular evening hunts, especially during damp weather
• Start sowing dwarf and climbing French beans, as well as runner beans, directly outdoors in warm weather
• Pick rhubarb stems as they develop, and water plants with liquid feed
• Start hardening off tender young plants, such as tomatoes and courgettes, ready for planting out in mild areas
• Sow batches of salad leaves and stir-fry crops every few weeks to provide continuous pickings
• Hang pheromone traps in apple and plum trees from May to July, to control pests
• Thin out seedlings, like carrots, from earlier sowings to ensure you get healthy, strong-growing plants
• Open fruit cage doors or lift some of the netting to ensure pollinating insects can get access to the flowers
• Remove all strawberry runners, so plants put their full energy into fruiting
• Keep plenty of fleece handy to protect young seedlings or fruit blossom, if late frosts are forecast

Earth up potatoes to increase yield

Greenhouse

• Water thirsty crops such as tomatoes, cucumbers and courgettes regularly as the weather starts to warm up
• Tie the stems of indoor tomatoes, cucumbers and aubergines to canes as they grow
• Plant heat-treated freesia corms in pots for fragrant flowers this summer
• Check plants regularly for pests, on shoot tips and the underside of leaves, and treat with biological controls if desired
• Put up shading to lower daytime temperatures and reduce scorching
• Open doors and vents on warm days, but close them in the evening as nights can still be cold
• Take cuttings of woody herbs such as hyssop, rosemary and thyme, and root in pots of gritty compost
• Keep pricking out seedlings as soon as they get their first true leaves, to avoid overcrowding and fungal diseases
• Start to harden off tender plants and bedding, ready for planting outside after the last frost
• Take cuttings from fuchsias, dahlias and pelargoniums
• Transplant tomatoes into growing bags or large pots, and tie their main stem to a cane or vertical wire for support

Feeding and watering tomatoes in a grow bag

Garden maintenance

• Scoop out pondweed, blanketweed and algae from ponds and water features
• Put soft tops on the tips of all canes, in borders, veg plots, pots and greenhouses, to prevent injury to eyes
• Apply wood treatment to wooden garden furniture to condition it for summer
• Set up an extra compost bin or a worm bin, so you can recycle more green waste from your kitchen and garden
• Apply nitrogen-rich summer lawn feed to encourage leafy growth
• Mow grass pathways through wildflower areas so you can walk in among the flowers
• Hoe bare soil and hand-weed beds weekly, so weeds don't have time to establish and set seed
• Put supports in place for clumps of perennials that are prone to flopping, such as top-heavy peonies or phlox
• Trim topiary regularly to promote bushy growth and keep it looking neat
• Sow grass seed or lay new turf by the end of this month, to create a new lawn or repair damaged patches
• Check shrubs for nests before you start any pruning, to avoid disturbing nesting birds
• Clean out and scrub bird feeders regularly to maintain hygiene
• Build sturdy wigwams and supports for climbers such as runner beans, sweet peas and morning glory
• Watch out for aphids on shoot tips and young foliage, and wipe them off or spray with a soap-based solution

Wipe off aphids with a mild soap based solution.