May is the month Irish gardeners have been waiting for. Frost risk is mostly behind us, the days are long and bright and almost everything you could want to grow can go in the ground or at least get started on a sunny windowsill.
For families, May is especially exciting. The big easy seeds such as sunflowers, runner beans, courgettes, carrots are all perfect for May sowing, and they're all exactly the kind of dramatic, fast-growing plants that hold a child's attention from seed to harvest.
Whether you have a garden, a balcony, or just a windowsill, there's something in this guide for you. And if you'd like every month's nature and growing activities planned and delivered to your door, take a look at our Little Sprouts monthly nature box — the May edition is all about seeds, growing, and the magic of Bealtaine.
May Planting Calendar for Ireland
Here’s a quick overview of what you can sow, plant, and harvest in May across Ireland. Use this as your month’s checklist:
| Stage | What to grow |
| Sow indoors (for planting out later) | Courgettes, cucumbers, squash, basil, dill, coriander, sweet corn, pumpkins |
| Sow outdoors / direct | Sunflowers, runner beans, French beans, carrots, rocket, cornflowers, beetroot, radish, lettuce, peas, spinach, kale |
| Plant out (hardened off seedlings) | Tomatoes (late May, sheltered), courgettes, cucumbers, sweet corn, brassicas started indoors |
| Harvest this month | Early lettuce and salad leaves, radishes, asparagus (if established), rhubarb, overwintered spinach |
| Frost risk in Ireland | Mostly passed by mid-May — but always check local forecast. Coastal and southern areas clear earlier than inland and northern. |
Frost dates in Ireland: Most of Ireland is frost free by mid-May, but inland areas, the midlands and higher ground can get late frosts until the end of May. Always check your local forecast before planting out tender seedlings. The rule of thumb: if in doubt, wait another week.
Best Plants to Grow with Kids in May
These are the seven plants we'd recommend for May sowing with children — chosen for quick results, easy handling, and the wow factor that keeps kids engaged from seed to harvest.
Sunflowers
🧒 Best age: All ages (3+)
⏱ Time to harvest: 10–14 weeks to bloom
⭐ Difficulty: Very easy
May is ideal for sowing sunflowers directly outside or into pots. The soil is warm enough that germination is fast and you'll see shoots in 7–10 days.
Use a large pot (at least 30cm deep) if growing without a garden. Dwarf varieties like Teddy Bear or Sunspot stay small and compact for windowsills; Mammoth and Giant Single will tower over the children by August.
☘ Irish tip: Sow directly outside now without needing to start indoors first. Water well after sowing and protect from slugs for the first few weeks.
🎮 Kids activity: Set up a weekly height chart on the wall or doorframe and measure the sunflower every Monday and mark the line. Children love watching the line race upward.
Runner Beans
🧒 Best age: Ages 4+ (big seeds, easy to handle)
⏱ Time to harvest: 12–14 weeks
⭐ Difficulty: Easy
Runner beans are one of the most satisfying plants to grow with children. The seeds are large and easy for small hands, they germinate quickly and by midsummer the children can pick pods directly from the plant.
Sow directly outside in May. Push two seeds 5cm deep, 15cm apart. They need something to climb such as a bamboo teepee, a fence or a trellis. French beans are a shorter, bushier alternative if space is tight.
☘ Irish tip: Runner beans love the Irish summer. Give them something tall to climb and they'll produce abundantly from July through September. Pick regularly to keep them cropping.
🎮 Kids activity: Build a bean teepee together from bamboo canes and string before sowing. Children feel enormous pride in a structure they helped make — and even more so when pods appear on it.
Carrots 🥕
🧒 Best age: Ages 3+ (scattering seeds)
⏱ Time to harvest: 12–16 weeks
⭐ Difficulty: Easy (needs right soil)
Carrots are a fantastic first vegetable for children, but they need some care with soil. They prefer light, stone-free, well-drained soil. If your soil is heavy or stony, grow them in a deep pot or a raised bed filled with peat-free compost.
Sow seeds thinly in shallow drills and cover lightly. The magic moment is pulling the first carrot from the earth, there's nothing quite like the look on a child's face.
☘ Irish tip: In Ireland, May sowings of carrots typically harvest between August and October. Protect against carrot root fly with a fine mesh barrier or grow in pots away from the soil.
🎮 Kids activity: Let the children make the drills (furrows) with their finger and scatter the seeds, even if they go in a bit thick, you can thin them later. The process of covering them up and patting them down is deeply satisfying.
Courgettes 🥬
🧒 Best age: Ages 5+ (planting out)
⏱ Time to harvest: 8–10 weeks
⭐ Difficulty: Easy and very rewarding
Courgettes are the most productive plant you can grow with children. One or two plants will produce more courgettes than most families can eat from July through September.
Sow indoors now (one seed per small pot, on its side) and plant out at the end of May once all frost risk has passed. They're large, tactile plants that children love tending and harvesting feels dramatic. They also grow happily in large containers or grow bags.
☘ Irish tip: Courgettes are one of the few vegetables that genuinely thrive in large containers or grow bags. They are perfect for balcony gardens and families without outdoor space. Water generously once established.
🎮 Kids activity: Let children harvest their first courgette with a pair of children's scissors. Cook it the same day. They can be grated into pasta, sliced on pizza or just fried in butter. The connection between growing and eating is the whole point!
Rocket 🌿
🧒 Best age: All ages
⏱ Time to harvest: 4–6 weeks
⭐ Difficulty: Very easy
Rocket is the fastest-gratifying thing you can grow with an impatient child. Sow it directly in a pot or tray in May and you'll be cutting leaves within 4–6 weeks. It needs very little soil depth, grows well on a windowsill. It can be cut and will regrow again!
To do this, harvest the outer leaves and it just keeps growing. The peppery flavour is surprisingly popular with children once they've grown it themselves.
☘ Irish tip: Sow little and often. A small pot every 2–3 weeks gives you a continuous supply through the summer rather than a glut. Bolt (go to seed) quickly in hot weather, so a shadier spot in midsummer is actually fine.🎮 Kids activity: Grow a pot of rocket labelled with your child's name. Let them cut their own leaves to add to a lunchtime sandwich or salad. The ownership of the whole process from sowing, watering, harvesting and eating is where the real learning lives.
Cornflowers 🌺
🧒 Best age: Ages 4+
⏱ Time to harvest: 10–12 weeks to bloom
⭐ Difficulty: Very easy
May is the last month for sowing cornflowers to guarantee blooms this summer. Scatter seeds directly where you want them to flower as they don't like being transplanted.
The vibrant blue flowers are stunning, they're loved by bees and butterflies, and they can be dried for nature journalling and craft projects. Plant them alongside cosmos or corn poppies for a meadow effect.
☘ Irish tip: Cornflowers are perfectly adapted to Irish conditions. They tolerate cool, damp summers better than many annual flowers. A sunny spot is ideal but they'll cope with partial shade.
🎮 Kids activity: Press and dry cornflower blooms in July for a nature journal page or a pressed flower craft. The colour holds beautifully when dried. A brilliant late-summer project that connects back to this May sowing.
Basil 🌿
🧒 Best age: Ages 3+ (sprinkling seeds)
⏱ Time to harvest: Harvest from 6–8 weeks
⭐ Difficulty: Medium
Basil is the most aromatic and immediately gratifying herb to grow with children. The smell of the leaves alone makes children stop and notice.
Sow indoors in May in a warm spot (basil hates cold) and keep on a sunny windowsill rather than outside until the weather is reliably warm. It's the perfect companion to tomatoes and makes children feel like real cooks when they harvest it.
☘ Irish tip: Basil is one of the trickier herbs in Ireland because it needs more heat than our summers reliably provide. Keep it on the warmest windowsill in the house rather than outside, or use a cloche outdoors. Buy a supermarket basil plant as backup.
🎮 Kids activity: Pick basil leaves together and make a simple tomato and basil salad. Children who have grown the basil themselves are dramatically more likely to actually eat it. This is the entire point of growing food with children.
Jobs to Do in the May Garden
Beyond sowing, May is a busy month in the Irish garden. Here’s what else to do:
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Earth up potatoes as the foliage grows: Draw soil up around the stems to prevent greening and encourage more tubers
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Harden off seedlings started indoors: Bring them outside for a few hours each day for a week before planting out fully
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Watch for slugs: May’s warmth and dampness is peak slug season in Ireland. Use copper tape around pots, beer traps, or organic slug pellets
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Pinch out broad bean tips once the first pods have set: This deters blackfly and encourages the beans to focus on pods rather than growth
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Begin feeding container plants: Once plants are actively growing, a liquid seaweed feed every 2 weeks makes a big difference
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Weed early and often: May weeds grow fast in the warm soil. A quick hoe every week takes minutes and saves hours later
Gardening in May Without a Garden
No outdoor space?
May is still a brilliant month for growing with children. All seven plants above can be grown in containers on a balcony or pots on a sunny windowsill.
Sunflowers, rocket, carrots, cornflowers, and basil all work particularly well in pots. See our full guide to gardening without a garden for Irish families for everything you need to know.
What to Plant in May in Ireland: Common Questions
Is it safe to plant out tender plants in May in Ireland?
From mid-May onwards, most of Ireland is frost-free and it’s safe to begin planting out tender seedlings. However, the midlands, north and inland areas can still get late frosts until the end of May.
Always check your local forecast. If you’re in Dublin, Cork, or coastal areas, you’re generally safe from mid-May. Further north or inland, wait until the last week of May to be certain.
What grows fastest from seed in May for impatient kids?
Rocket wins this one. You’ll be harvesting leaves in 4–6 weeks. Radishes are even faster (3–4 weeks) and are brilliant for children because the whole cycle from seed to pulling from the ground, happens in less than a month. Cress on a wet paper towel is the classic instant-gratification option and works at any age.
Can I still sow sunflowers in May in Ireland?
Yes, May is actually the ideal time to sow sunflowers directly outside in Ireland. The soil is warm enough for fast germination and the long Irish summer days will push them to full bloom by August.
Starting earlier (March/April) indoors is possible but not necessary. May direct sowings often catch up with indoor-started seeds within a few weeks.
What vegetables can children actually harvest themselves in summer from a May sowing?
From a May sowing, children can expect to harvest rocket from late June, radishes from early July, carrots from August onwards, runner beans and courgettes from July through September, and sunflower seeds in September for birds or snacking.
The most satisfying harvests for children are anything they can pull, pick or cut themselves. Runner beans, carrots, and courgettes are the classics!
Do I need to water seeds every day in May?
Freshly sown seeds need consistent moisture to germinate. Check the soil every day and water lightly if the surface feels dry.
Once seedlings are established (showing their first true leaves), you can ease off to every 2–3 days. In pots and containers, daily watering is often needed in May because containers dry out faster than garden soil, especially on windy days.
Ready to Grow Together This May?
Growing things in May with children is one of the most rewarding things you can do together. The seeds go in quickly, the results arrive before the summer holidays are over, and the satisfaction of pulling your own carrot or picking your own runner bean is something children remember.
If you’d love more seasonal nature and growing activities with everything planned, sourced, and delivered each month, our Little Sprouts Garden Box is designed exactly for families like yours. Seeds, Irish folklore stories, nature crafts, and growing guides, all together in one beautiful monthly box for children aged 3–9.
You might also enjoy our guides to growing sunflowers with kids in Ireland and gardening without a garden for Irish families, both perfect for May projects.