Sunflower Seeds in Ireland
Sunflower seed sold to sow and sunflower seed sold to feed birds are two different products, and this page is about the first kind. Growing sunflowers from seed in Ireland is genuinely easy, which is why it is the classic children's project, but two things catch people out every year: slugs strip the seedlings in May, and wind flattens the tall varieties in August. Here are the sowing dates that work here, the varieties worth growing in an Irish garden, and where to buy the seed in Ireland.
Sowing and harvest calendar for Ireland
Months shaded below are the reliable windows for Irish conditions.
Quick facts
- Botanical name
- Helianthus annuus
- Difficulty
- Easy, good first crop
- Hardiness
- Half hardy, protect from frost
- In Ireland
- Grows outdoors unprotected
- Germination
- 5 to 14 days at 15 to 22C
- Sowing depth
- 2cm
- Spacing
- 45cm apart, 60cm between rows
- Position
- Full sun
- Containers
- Grows well in pots
- Sowing to flowering
- 11 to 18 weeks
- In flower
- July to October
Sowing depth and spacing
Drawn to scale from the figures in this guide.
How deep, seen from the side
How far apart, seen from above
The best sunflower varieties for Irish gardens
Picked for how they perform in a cool, damp, short summer rather than for catalogue photos.
Russian Giant
Open pollinated / Tall single-headed
The one children want to grow. Sow it early, stake it properly, and give it the most sheltered spot you have.
Growing notes and stockistsVelvet Queen
Open pollinated / Branching, cut flower
The best all-round sunflower for an Irish garden. Short enough to stay standing, and it flowers for months.
Growing notes and stockistsTeddy Bear
AGMOpen pollinated / Dwarf double
The sunflower for a container, a balcony or a small child, and the only one that ignores Irish wind entirely.
Growing notes and stockistsLemon Queen
Open pollinated / Branching, pale lemon
The one to grow for bees and for cutting. Soft lemon flowers over months rather than one loud yellow head.
Growing notes and stockistsHow to sow sunflower seeds
The seeds are big, easy to handle and germinate readily, which is why they suit children. Sow one or two per 9cm pot of ordinary compost, about 2cm deep, water once and keep them somewhere bright at 15 to 22C. They come up in five days to a fortnight. Thin to the stronger seedling if both appear.
March and April sowings need light more than heat. A warm dark spot gives you a pale stem that flops, so as soon as the shoot appears the pot goes onto the brightest windowsill in the house, turned daily so it grows straight.
Direct sowing outdoors works from May once the soil is no longer cold to the touch. Sow two or three seeds at each station, 2cm deep, and thin to the best one. Cover the spot with fine mesh until the seedlings are through, because mice and birds take direct sown seed regularly.
Harden off pot-raised plants over a week before they go out. Plant them deeper than they sat in the pot, right up to the seed leaves, which gives a slightly better anchored plant.
Growing on in Irish conditions
Put the stake in on the day you plant, not in July when the plant is already leaning. Everything else about growing sunflowers here is straightforward; this is the part that decides the outcome. For a giant variety use a 2.4m timber stake driven at least 45cm into the ground, and tie the stem loosely to it every 40cm as it climbs. A bamboo cane will simply snap.
Spacing depends on the type. Dwarf varieties such as Teddy Bear sit happily 20 to 25cm apart or three to a large pot, branching cut-flower types want about 45cm, and giants want 60cm and full sun all day.
Choose the sheltered side of a wall, hedge or shed. Planting a block of several together rather than one in isolation lets them support each other and looks better besides. In an exposed coastal or upland garden, accept that a 3m variety is not realistic and grow a 1.5m branching one instead, which will flower for far longer anyway.
Sunflowers are thirsty and hungry in proportion to their size. Water deeply in dry spells rather than lightly every day, and a feed of general purpose fertiliser in June helps the giants. Ordinary garden soil suits the smaller varieties without any special treatment.
Slugs are the other constant. Keep bottle collars on until the plants are well past 20cm tall, which is the point at which they stop being worth a slug’s attention.
Cutting flowers and what to do with the heads
For cutting, pick branching varieties and cut in the early morning when the flower has just opened and the back of the head is still green. Strip the lower leaves, put the stems straight into deep water, and expect around a week in the vase. Cutting the first flower makes a branching plant produce more side blooms, so the more you cut the more you get, right through into October.
Single-headed giants give you one flower and that is that, so most people leave them standing.
For seed, wait until the back of the head turns yellow then brown and the seeds are plump and dark. If a wet spell threatens, cut the head with 30cm of stem and hang it upside down in a shed or porch with a paper bag tied loosely around it to catch what falls. Rub the dried seed out with your thumbs.
Whatever you do not want, leave outside on the plant. A standing sunflower head feeds finches and tits through the winter, and the stems give insects somewhere to overwinter. Clear them in spring instead.
What goes wrong with sunflowers in Ireland
Wind snapping the stems
Signs: A tall sunflower folded over at ground level or bent at right angles halfway up after a windy night, usually just as the head has got heavy.
What to do: Stake at planting, not when it starts to lean, and use something serious: a 2.4m timber stake or a length of scaffold plank driven well in, not a bamboo cane. Tie loosely in three or four places as the plant grows. Plant against a wall, fence or hedge on the sheltered side, and if you cannot offer shelter, grow a 1.5m branching variety instead of a giant.
Slugs and snails on seedlings
Signs: Young plants vanishing overnight, or a bare chewed stem where a seedling stood the evening before.
What to do: Slugs destroy more Irish sunflowers than anything else, and a direct-sown seedling can be gone before you notice it germinated. Raise plants in pots to 15 or 20cm tall before planting out, put a cut-off plastic bottle around each one for the first fortnight, and patrol with a torch on the first few damp evenings after planting.
Seed eaten before it germinates
Signs: Direct sown rows where nothing comes up at all, sometimes with small holes or disturbed soil.
What to do: Mice and birds find sunflower seed as attractive as we intend them to. Cover a direct sown row with fleece or fine mesh until the seedlings are up, or sidestep the problem entirely by starting the seed in pots on a windowsill and planting out.
Heads droop and rot
Signs: The back of the flower head turning brown and mushy in wet weather, often with grey mould, before the seed has filled.
What to do: A wet Irish September on a big flat head that holds water is a difficult combination. Grow varieties with smaller heads that hang forward and shed rain, keep plants spaced so air moves through, and cut heads for drying at the first sign of rot rather than waiting for them to finish outdoors.
Seed does not ripen
Signs: Heads that look finished but contain flat, empty, papery seeds when you rub them out.
What to do: Partly weather and partly pollination. A dull cool summer will not fill the seed, and there is nothing to be done about that. Give the plants the sunniest spot you have, sow by mid-April so the heads open in good time, and grow varieties that produce pollen rather than the pollen-free florist types, since pollen-free sunflowers set very little viable seed.
Where to buy sunflower seeds in Ireland
Irish suppliers that stock this, so postage stays domestic and seed arrives in time to sow. These are plain links, not paid placements.
Order online
- Fruit Hill Farm Irish Certified organic sunflower seed Bantry based supplier to Ireland's commercial organic growers. Certified organic and biodynamic seed, mail order only. Visit Fruit Hill Farm , Co. Cork
- Brown Envelope Seeds Irish Mixed sunflowers, organic seed grown in West Cork Grows and saves its own certified organic seed in West Cork, so the varieties are already adapted to Irish conditions. Visit Brown Envelope Seeds , Co. Cork
Garden centres and mixed retailers
- Mr Middleton Irish Eighteen sunflower varieties, the widest choice here Mail order arm of a long established Mary Street shop, carries the familiar named varieties the organic specialists skip. Visit Mr Middleton , Co. Dublin
- Johnstown Garden Centre Irish Large branded flower seed range Third generation family business near Naas with the widest branded range, though popular varieties sell out by midsummer. Visit Johnstown Garden Centre , Co. Kildare
- The Organic Centre Irish Small organic flower seed list from Co. Leitrim Registered Irish charity at Rossinver with a 19 acre demonstration garden behind the seed catalogue. Visit The Organic Centre , Co. Leitrim
Common questions
When should I sow sunflower seeds in Ireland?
Sow indoors in March or April on a bright windowsill, or direct outside in May once the soil has warmed. The indoor route is much the safer one here, because it gets the plant past the size at which slugs can destroy it in a night and it buys three or four weeks of season, which matters for the tall varieties that need every week they can get. Sowing after the end of May is possible but the plant will flower late and may be caught by autumn weather.
Can I sow the sunflower seeds from a bag of bird food?
Sometimes. Whole black sunflower seed sold for bird feeders will often germinate, which is why volunteer sunflowers appear under feeders every summer. But you have no idea of the variety, the age or whether the batch was heat treated, so germination is patchy and the plants are a lottery. Hulled sunflower hearts and anything roasted or salted for human snacking will never germinate. If you want a particular height or colour, buy seed sold for sowing.
Which sunflower grows the tallest?
For a growing competition, choose a named giant such as Russian Giant, which will pass 3m in good conditions. Getting there in Ireland takes an early indoor sowing, rich soil, full sun, generous watering and above all shelter, since the tallest plant in an exposed garden is simply the first one to be blown down. If children are competing, measure to the top of the flower rather than the leaves, and agree in advance that a plant flattened by wind still counts.
Do sunflowers come back every year?
The common garden sunflower, Helianthus annuus, is an annual, so it flowers, sets seed and dies in one season and has to be sown again. Some plants will self-seed here in a mild year and appear in the same bed the following spring, though rarely where you wanted them. There are perennial Helianthus species sold for borders, but they are different plants with much smaller flowers and none of the height.
How do I stop my sunflower falling over?
Stake it properly from the start and put it somewhere sheltered. A tall sunflower has a hollow stem and a heavy head, and Irish soil is often soft and wet by the time the head fills, so the whole plant can lever itself out of the ground rather than break. Drive a stout stake in at planting time, tie in every 40cm or so as the plant grows, and firm the soil around the base. Growing several together in a block, or against a wall, helps enormously.
Should I cut the heads down or leave them standing?
Leave at least some of them standing. A ripe sunflower head is a free bird table through the worst part of the Irish winter, and goldfinches, greenfinches, tits and siskins will strip it. Cut and dry indoors only the heads you want for seed you intend to keep, or those that are rotting in wet weather. Leaving the rest is the honest link between growing sunflowers and the bird seed people buy in bags.