May is the busiest and most exciting month in the British gardening year. The soil has warmed up, the risk of frost is fading by the end of the month, and almost everything you sow or plant will grow quickly. This guide walks you through the gardening jobs for May that matter most, area by area, with practical timings, kid-friendly ideas and the mistakes that are easiest to avoid.
What May is really about in the garden
May is a month of transitions. The tender plants you have been growing on indoors are ready to head outside, the hungry gap in the veg patch is closing, pests are waking up in earnest, and the lawn is growing faster than you can mow it. If you do only three things this month, make them these: finish your tender sowings, harden off and plant out, and stay ahead of the weeds.
Jobs in the vegetable patch
- Sow directly: carrots, beetroot, salad leaves, radishes, spring onions, peas, French beans, runner beans, sweetcorn (late May), courgettes (late May).
- Plant out after hardening off: tomatoes (outside from late May in the south), courgettes, pumpkins, squash, cucumbers, leeks, brassicas.
- Earth up potatoes: draw soil up around the stems once they are 20cm tall to protect the developing tubers.
- Stake peas and beans early. They grow far faster in May than most people expect.
- Sow for succession. A short row of salad leaves every two weeks gives you fresh leaves right through to autumn.
If you have been growing runner beans on the windowsill, May is the month they finally head outside. It is also a brilliant project to do with children — our long-running runner bean experiment has a gentle week-by-week structure that kids love.
Jobs in the flower borders
- Plant out summer bedding from the middle of the month once the last frost has passed in your area.
- Stake tall perennials — delphiniums, peonies, phlox and tall asters all benefit from support before they flower.
- Deadhead tulips and daffodils but leave the foliage to die back naturally to feed next year’s bulb.
- “Chelsea chop” tall herbaceous perennials like sedum, helenium and phlox in the last week of May to delay flowering and keep plants bushy.
- Sow hardy annuals direct: cornflowers, calendula, nigella, poppies and nasturtiums will all catch up fast.
- Take softwood cuttings of hydrangeas, fuchsias, lavender and penstemons.
Lawn care in May
May is when most lawns properly wake up. Three simple rules will carry you through:
- Raise the mower blade. Keep the grass longer (around 4–5cm) — it holds moisture better, shades out weeds and looks greener.
- Mow weekly at minimum. Grass grows fastest in May and June. Two weeks away and you will be scalping it on return.
- Leave a “No Mow May” patch if you can — a small unmown corner is brilliant for pollinators and takes no effort.
A simple spring feed at the start of the month, applied before rain, will green up a tired lawn in a week.
Greenhouse and cold frame
- Open vents and doors on warm days. Greenhouses can hit 35°C by mid-morning in May and cook young plants in hours.
- Plant out tomatoes into greenhouse borders or large pots from mid-May onwards.
- Pinch out side shoots on cordon tomatoes as soon as they appear.
- Water in the morning, not the evening, to keep humidity down and reduce fungal problems.
- Put out yellow sticky traps to monitor whitefly and aphids early.
Fruit garden
- Net soft fruit — strawberries, raspberries, currants and blueberries are all easy pickings for birds by late May.
- Thin strawberry flowers lightly to encourage fewer but bigger fruit.
- Mulch around fruit bushes with compost or well-rotted manure.
- Check apple and pear trees for signs of sawfly and aphid damage; squash any curled leaves between your fingers.
Pest watch
Five pests to keep a close eye on in May:
- Slugs and snails on hostas, dahlias and young vegetable plants. Go out with a torch after rain.
- Aphids on rose buds, broad beans and fruit trees. Squash the first colonies by hand before they explode.
- Carrot root fly — cover carrots with fine mesh or insect-proof fleece at sowing.
- Lily beetle — bright red, easy to spot, drops to the soil when disturbed. Pick off by hand daily.
- Asparagus beetle — check stems morning and evening and crush eggs between your fingers.
Week-by-week plan for May
| Week | Priority jobs |
|---|---|
| Week 1 (1–3 May) | Final direct sowings of carrots, beetroot and salads; harden off tender plants; spring lawn feed |
| Week 2 (4–10 May) | Earth up potatoes; stake peas and perennials; net soft fruit; take softwood cuttings |
| Week 3 (11–17 May) | Plant out courgettes, squash and runner beans in the south; sow sweetcorn; mow weekly |
| Week 4 (18–24 May) | Plant out tomatoes; deadhead tulips; stay on top of slugs; sow a second row of salads |
| Week 5 (25–31 May) | “Chelsea chop” perennials; last tender plantings go out; start regular watering of pots; holiday-prep the garden |
Kid-friendly jobs for May half term
May half term is the perfect moment to get children involved in the garden — the weather is usually kind and most jobs are quick, visible and rewarding. A few easy starters:
- Sowing sunflowers for a height competition
- Planting up a single pot with strawberries, basil and a trailing flower
- A daily slug patrol with a torch (surprisingly popular)
- Building a simple bean teepee from canes and string
- A garden minibeast hunt and tally
We have a longer piece on kids’ gardening ideas for May half term if you want more options.
NT garden visits in May — is membership worth it?
May is the single best month to visit a National Trust garden, and a £45 family gate ticket for one property is almost the cost of a monthly membership. Here’s the honest maths if you’re planning to get out and about this month.
Picture a family of four (2 adults, 2 under-16s) making four garden days out between May and the end of summer — say Sissinghurst for the famous White Garden, Hidcote for the hedges and garden rooms, a local property like Blickling or Bodnant, and a cross-country stop at Stonehenge on the way home from a holiday. Gate prices work out at roughly: Sissinghurst £45 family + £5 parking = £50; Hidcote £45 + £5 = £50; Blickling £45 + £5 = £50; Stonehenge £88.80 (parking included). That’s £238.80 paid at the gate.
An annual National Trust family membership — 2 adults and all children under 18 — is £176.40 by annual Direct Debit, and covers every garden, parking at over 300 properties, and entry to Stonehenge (English Heritage manages the stones, but NT England members book a free ‘affiliate member’ ticket on the EH site and walk in that way — the long-standing NT/EH reciprocal). Sign up online by Direct Debit and you also get a free Guest Pass to share with a grandparent or friend.
On four garden visits alone you’re about £62 better off as a member — and every garden, parkland walk or coastal car park you use for the rest of the year is pure savings.
One more budget point worth knowing. National Trust family membership can be paid by monthly Direct Debit rather than in one lump sum — £14.70 a month for a two-adult family, or £9.10 a month for a one-adult family — spread across twelve instalments. That can be a lot easier to plan around than a clutch of peak-season family tickets arriving all at once during the school holidays.
Five mistakes to avoid in May
- Planting tender crops out too early. A late frost can wipe out courgettes and beans overnight. If in doubt, wait until after mid-May in the north.
- Forgetting to harden off. Four to seven days of gradual outdoor exposure makes a huge difference to survival.
- Over-watering seedlings. Cool, damp compost kills more young plants in May than drought.
- Neglecting the greenhouse on warm days. Twenty minutes of full midday sun with vents closed is enough to scorch tomatoes.
- Cutting the lawn too short. A stressed lawn is a weedy lawn. Keep the blade high.
Frequently asked questions
When is it safe to plant tomatoes outside in the UK?
In the south of England, outdoor tomatoes can usually go out from around 20 May, once the risk of frost is very low. In the Midlands and the north, it is safer to wait until the first week of June. Greenhouse or polytunnel tomatoes can go in from the start of May.
What should I sow in May for a continuous harvest?
Short rows of salad leaves, radishes and spring onions every two weeks; a single sowing of carrots and beetroot at the start of the month; and a late sowing of runner beans, French beans and courgettes in the third week for a later, fresher crop.
Is No Mow May actually worth it?
A full month of not mowing can leave you with a tough job in June, but leaving a permanent unmown patch — even a square metre — genuinely helps pollinators. A sensible compromise is to mow paths through longer areas and let the rest grow.
Should I feed my lawn in May?
Yes — a single spring feed applied just before rain will green up a tired lawn quickly. Avoid feeding during a drought and water in thoroughly if no rain is forecast.
More gardening from the blog
Related seasonal guides
- When to Prune Roses: a month-by-month UK guide
- May Bank Holidays 2026: the family days out guide
- May Half Term 2026: our day-by-day family guide
Stay on top of the basics in May, give yourself a gentle week-by-week routine, and the garden will be a genuine pleasure all the way through to October. A little effort now is worth a great deal later in the summer.
Bringing the garden indoors too? See our guide to the best house plants for every room — which house plants suit a bright room, a dim bathroom or a north-facing corner, and how to keep them alive.
Thinking ahead to autumn, October and November are the months for planting garlic — one of the easiest crops to grow and one that all but looks after itself over winter.
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