What to do in the garden in May
May is one of the most rewarding months in the garden. Growth is strong, borders are filling out and early summer colour is starting to build. With longer days and milder temperatures, plants move quickly from fresh spring growth to full seasonal momentum.
That said, do not get complacent. Late frosts are still possible, especially in colder parts of the UK. Keep fleece handy and delay planting out tender plants until you are confident temperatures are consistently above 12°C overnight.
If you are laying new turf or establishing lawns, act before prolonged dry spells arrive. Warm soil encourages root development, but young turf will struggle if allowed to dry out. In greenhouses, ventilate well on sunny days and shade young plants from intense midday light.
Watering becomes more important this month. Newly planted trees, shrubs and bedding need consistent moisture to establish properly. Apply mulch around the base of plants to conserve moisture and suppress weeds. Stay on top of weeding while growth is soft and manageable.
Above all, monitor plants regularly for early signs of pests. Acting quickly prevents larger infestations later in the season.
Ornamental garden jobs in May
• Remove any frost damaged growth from early flowering plants.
• Treat roses preventatively if disease pressure is high.
• Keep borders weed free with regular hoeing.
• Continue deadheading spring bulbs, leaving foliage until fully yellowed.
• Carry out the Chelsea chop on plants such as nepeta, sedum, echinacea, aster and salvia to encourage compact growth and later flowering.
• Trim rosemary, thyme and sage to keep them bushy.
• Cut back withered daffodil and tulip stems once fully yellow.
• Neatly edge lawns and borders to maintain definition.
• Prune spring flowering clematis once blooms fade.
• Stake tall herbaceous perennials before they flop.
• Lift and divide overcrowded daffodil clumps if flowering was poor.
• Harden off tender plants before planting outside.
• Plant out dahlias towards the end of the month once frost risk has passed.
• Protect young plants from slugs and snails.
Vegetable garden jobs in May
• Harvest asparagus regularly while spears are tender.
• Direct sow French beans and sweetcorn once soil has warmed.
• Earth up potatoes as foliage develops.
• Harvest early crops such as radish and lettuce.
• Delay planting tomatoes outdoors until nights are reliably warm.
• Sow pumpkins, cucumbers, courgettes and squash under cover, planting out later in the month if conditions allow.
• Lift and divide mint to keep it vigorous.
• Mulch fruit plants to conserve moisture and suppress weeds.
Other essential jobs in May
• Feed and mow established lawns regularly.
• Treat lawn weeds if required.
• Maintain a consistent weeding routine.
• Keep paths and borders clear of debris.
• Increase watering frequency during warm spells, especially for containers and newly planted areas.
Top products for May gardening
Multi cell seed trays
Strong, reusable trays for raising bedding plants and vegetables efficiently.
Peat free compost with loam
Balanced growing media to support early plant development.
Heavyweight plant pots
Durable recycled pots designed for stability and healthy root growth.
Composted bark
Organic soil conditioner to improve structure and moisture retention.
Organic fertiliser
Natural feeds suitable for flowers, lawns, fruit and vegetables.
May is about management and momentum. Stay proactive with feeding, watering and pest control, and your garden will carry strong growth into summer.
