How to Grow Achillea
from Seed in the UK
A complete guide to one of the cottage garden's most versatile and rewarding plants — from sowing through to those magnificent flat-topped flowerheads, and the very best dried flowers you will ever cut
Achillea — yarrow — is one of those plants that rewards you so generously for so little effort that it feels almost unfair on the rest of the garden. Given a sunny spot and reasonable drainage, it flowers prolifically from midsummer right through to autumn, attracts pollinators in extraordinary numbers, laughs in the face of drought, and then — just when you think it's finished — offers some of the most beautiful and long-lasting dried flowers you will ever cut. There is really very little not to love.
It is also a plant of remarkable variety. The achillea genus encompasses everything from the soft, feathery-leaved common yarrow of hedgerows and meadows to the tall, elegant flat-topped cultivars that have become essential in the naturalistic planting palette championed by designers like Piet Oudolf, and the compact pompom-flowered Achillea ptarmica that looks for all the world like a double white button chrysanthemum. This guide covers them all — how to tell them apart, how to grow them from seed, and how to get the very best from them both in the garden and in a vase or dried arrangement.
Quick Facts at a Glance
Plant Type
Hardy Perennial
Sowing Time
Feb–Apr indoors or Apr–Jun direct
Flowering Months
June – September
Position
Full sun, well-drained
Eventual Height
30–100cm (variety dependent)
Difficulty Rating
2 out of 5 — Easy
Understanding Achillea — The Main Types
The achillea genus is broader and more diverse than most gardeners realise. Before you sow, it is worth understanding the main groups — they share the same basic cultural requirements but have quite different characters in the garden and quite different qualities as cut and dried flowers.
Achillea millefolium
Common Yarrow
The most widely grown and most varied group. Feathery, aromatic, finely divided foliage with flat-topped flowerheads in a spectacular range of colours — from white through every shade of pink, red, salmon, apricot, orange and deep crimson. Named cultivars include Rubra, Terracotta, Paprika and countless mixed series. Medium height, 50–70cm. Spreads via rhizomes over time, forming generous colonies. Excellent for cutting and drying.
Achillea filipendulina
Fern-leaf Yarrow
The tall, architectural achillea. Stiff upright stems to 100cm or more carrying large, flat-topped flowerheads in warm shades of gold and yellow. The RHS AGM variety 'Cloth of Gold' is probably the finest. Robust and statuesque — a real structural plant in the border. Outstanding for drying, where the rich golden colour holds for months or even years. More upright and clump-forming than millefolium.
Achillea ptarmica
Sneezewort / Marshmallow
The most distinctive of the three main groups. Narrow, undivided leaves and double white pompom flowers on branching stems to 60–70cm. 'The Pearl' and 'Marshmallow' are the classic varieties — their button-like double flowers look almost like white ranunculus or double feverfew. Particularly popular with florists. Less drought-tolerant than the other groups and prefers slightly damper conditions. Spreads enthusiastically.
Mixed & Species Types
Other varieties
Seed packets often contain mixed collections combining millefolium cultivars in a wide range of colours — these are excellent value and give a cheerfully varied, naturalistic result. Species types from the wild, including the native white-flowered common yarrow, are also worth growing for their ecological value, particularly for beetles and parasitic wasps which rely heavily on yarrow as a habitat plant.
Which Should You Grow?
For the widest colour range and easiest growing — A. millefolium mixed or named varieties. For architectural drama and exceptional dried flowers — A. filipendulina. For florist-quality white cut flowers — A. ptarmica. Many cottage gardeners grow all three alongside each other for a season-long display with extraordinary range of colour, form and texture.
When & How to Sow
Achillea is a hardy perennial, which means plants sown this year will establish in their first season and flower more generously in every subsequent year, building into increasingly impressive clumps. First-year plants may flower modestly or not at all depending on when they are sown — this is entirely normal and well worth the patience.
Indoor Sowing — February to April (Recommended)
Sowing indoors gives the longest possible growing season and the best chance of flowers in year one. Use a heated propagator or warm windowsill, sow on the surface of fine seed compost without covering (achillea is a light-dependent germinator), and expect germination within two to three weeks at 18–20°C. Prick out once large enough to handle and grow on in a cool, light position before hardening off.
Direct Sowing — April to June
Achillea can be sown direct once the soil has warmed in spring. Scatter seed thinly over a well-prepared surface, barely cover with fine soil or vermiculite, and keep moist until germination. Direct-sown plants establish confidently but are unlikely to flower in their first year. This is the simplest approach and gives perfectly good results — you simply have to accept that year one is about establishing the plant.
Achillea filipendulina 'Cloth of Gold' — one of the finest achilleas for both garden impact and dried flowers. Those warm golden flowerheads hold their colour beautifully for months when dried.
Step by step — indoor sowing:
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Fill small pots or modules with fine seed compost. Firm gently and water before sowing — achillea seed is tiny and easily washed away. Peat-free seed compost works well; add a little vermiculite if your mix feels heavy.
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Sow on the surface — do not cover. Achillea seed needs light to germinate. Scatter seed as thinly as possible directly onto the compost surface and press gently to ensure contact. Do not cover with compost or vermiculite.
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Water from below. Stand the pots in a tray of water until moisture has wicked to the surface, then remove. This avoids dislodging the tiny surface-sown seeds. Cover loosely with a clear propagator lid.
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Germinate at 18–20°C. A heated propagator is ideal. Germination typically takes 10–21 days and can be erratic — don't give up if nothing appears in the first two weeks. Keep the compost evenly moist but not wet.
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Prick out carefully. Achillea seedlings are small and delicate. Once they have two true leaves, prick out into individual small pots using a dibber or pencil to handle by the leaf rather than the stem. Grow on in a cool, light, frost-free space.
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Harden off before planting out. Move plants outside to a sheltered spot for increasing periods over two weeks before planting into their final position after the last frosts. Space 30–45cm apart depending on variety.
Surface Sowing — The Critical Point
The single most common reason for achillea seed failing to germinate is covering it. Achillea is a light-dependent germinator — the seed requires light to trigger germination and buried seed simply won't sprout. Always sow on the surface and press gently to ensure contact with the compost. If in doubt, do not cover.
No Pinching Needed — Division is the Key Step
Unlike dahlias or sweet peas, achillea genuinely does not benefit from pinching out — it naturally produces multiple branching stems and flowers freely without any intervention. The equivalent transformative step for achillea is division, which becomes relevant from the plant's second or third year and keeps established clumps performing at their very best.
Achillea ptarmica 'Marshmallow' — the double white pompom flowers that make this the florist's favourite achillea. Spreads freely and benefits from division every two to three years.
How and When to Divide
Divide established achillea clumps every two to three years, in spring as new growth begins or in early autumn after flowering. Lift the whole clump with a fork, separate into smaller sections — each with a good root system and several shoots — and replant the strongest pieces at the same depth. Discard the exhausted woody central portion. Dividing not only prevents congestion and maintains vigour but also multiplies your plants rapidly — a single clump can yield six or eight new plants at each division.
Staking
Taller varieties — particularly A. filipendulina types reaching 80–100cm — can lean or flop in exposed positions, especially in very fertile soils where growth is lush. Grow-through supports placed in spring when plants are around 30cm tall are the neatest solution. In sheltered gardens, correctly spaced achillea will typically support itself through interplanting with neighbouring plants. Avoid overly rich, nitrogen-heavy soils which encourage weak, floppy growth.
Growing On Tips
Achillea is one of the most straightforward perennials to grow well, with just a handful of key requirements that make all the difference between a plant that thrives and one that merely survives.
Achillea millefolium 'Rubra Red' — one of the most striking of the coloured yarrows, with deep crimson flowerheads that fade beautifully to soft rose and warm pink as the season progresses.
Sun & Position
Full sun is non-negotiable for achillea performing at its best. A minimum of six hours direct sunlight per day is required for good flowering and strong stems. Plants in too much shade become leggy, flower poorly and are far more susceptible to mildew. South or west-facing borders are ideal. A. ptarmica tolerates slight shade better than the other groups.
Soil & Drainage
Well-drained soil is essential — achillea is genuinely drought-tolerant once established but will not tolerate waterlogged conditions, which cause root rot and crown death over winter. Lean to average soil produces the strongest, most upright growth and the best flower colour. Very rich or clay soils should be improved with grit before planting. Once established, achillea is remarkably tolerant of poor, dry conditions.
Watering
Water young plants regularly while establishing, particularly in their first summer. Once established — from the second year — achillea is one of the most drought-tolerant border perennials available. During prolonged dry spells a deep watering every week or two is sufficient for millefolium types; ptarmica appreciates slightly more moisture. Avoid overhead watering which can encourage mildew.
Feeding
Achillea thrives in lean conditions and generally needs very little feeding. A light dressing of balanced granular fertiliser in early spring is more than sufficient and encourages good flowering without pushing the floppy, over-lush growth that nitrogen-heavy feeding produces. In very poor soils, a mid-season liquid feed can help — but less is genuinely more with achillea.
Deadheading & Cutting Back
Deadheading spent flowerheads promptly encourages the production of new flowering stems and can extend the season significantly. Cut back to a visible side shoot or bud rather than just removing the flowerhead. In autumn, cut the whole plant back to around 10cm once it has died back. Some gardeners leave the stems standing through winter for structural interest and wildlife habitat — both approaches work well.
Wildlife Value
Achillea is one of the most ecologically valuable plants in the cottage garden — the flat-topped flowerheads provide a landing platform for an extraordinary range of insects including bumblebees, hoverflies, parasitic wasps, butterflies and beetles. It is particularly important for parasitic wasps which prey on aphids and other garden pests. An RHS Plants for Pollinators recommendation is entirely well deserved.
Common Problems & How to Fix Them
| Problem | Likely Cause | What to Do |
|---|---|---|
| No germination | Seed covered or too cold | Achillea is a surface-sower — seed buried even a millimetre will not germinate. Resow on the surface at 18–20°C with no covering. Be patient — germination can take up to three weeks and is often erratic. |
| Powdery mildew | Dry at roots, poor airflow, shade | The most common achillea problem, particularly in late summer. Water at the base, not overhead. Improve airflow by planting at correct spacing. Remove affected leaves promptly. A full-sun, well-drained position prevents most mildew issues. A. ptarmica is most susceptible. |
| Leggy, floppy stems | Too much shade, overly rich soil, no support | Move to a sunnier position — achillea in shade is always disappointing. Avoid high-nitrogen feeding. Place grow-through supports in spring. Choose compact varieties for exposed positions. |
| Poor flowering | Insufficient sun, congested clump, young plant | Ensure full sun. If an established plant is flowering poorly, it likely needs dividing — lift, split and replant the vigorous outer sections. First-year plants often flower modestly; performance improves greatly in year two and three. |
| Colour fading quickly | Heat, variety characteristic, or natural ageing | Many achillea varieties naturally fade from their original colour to softer tones as the flowers age — this is a feature rather than a fault and produces beautiful multi-toned effects within a single flowerhead. Cut for drying before this happens if you want the original colour preserved. |
| Spreading too aggressively | Rhizomatous spread, self-seeding | A. millefolium spreads via rhizomes and can colonise aggressively. Divide regularly, remove unwanted spread in spring when it is easy to dig, and deadhead before seed sets if self-seeding is a concern. A. ptarmica also spreads readily — both are best in larger borders where spreading is welcome. |
| Crown rot over winter | Waterlogged soil in cold weather | Achillea crowns are vulnerable to rotting in cold, wet soils. Improve drainage with grit, raise planting level slightly, or move to a better-drained position. Plants in clay soils are most at risk. Mulch with gravel or grit around the crown rather than organic matter. |
When to Expect Flowers
Indoor-sown achillea started in February or March will typically begin flowering from June or July of the same year — particularly compact millefolium varieties which tend to flower freely in their first season. Filipendulina types are slightly slower and may not flower meaningfully until their second year. Once established, all achillea types flower from June through to September, with some varieties extending into October in mild autumns.
The great advantage of achillea as a perennial is that performance genuinely improves year on year. A modestly flowering first-year plant becomes a generous second-year clump and a spectacular third-year colony that needs dividing. The long-term investment is one of the best in the cottage garden.
Once established, achillea flowers reliably from June right through to September — one of the longest flowering seasons of any hardy perennial.
For Flowers in Year One
To maximise the chance of flowers in the first year, sow as early as February indoors with gentle heat, prick out promptly, grow on in good light, and plant out in a well-prepared sunny bed in May. Compact millefolium varieties and named cultivars selected for first-year performance — such as many of the mixed series — will typically reward early sowing with flowers by July or August of the same year.
Cutting & Drying — Where Achillea Truly Excels
If achillea were only a good garden plant, it would still be worth growing. But as a dried flower, it is genuinely exceptional — one of the very finest in the cottage garden repertoire, with colours that hold for months or even years and structural flowerheads that retain their form long after cutting. A single established plant can yield dozens of stems for drying across a season, making it one of the most productive dried flower crops you can grow.
Cutting fresh for the vase
Cut achillea stems when the flowerheads are fully open but before any browning begins at the edges — typically when about three-quarters of the tiny individual florets within each head are open. Cut early in the morning, long stems to a side shoot, and place immediately into cool deep water. Condition for several hours in a cool dark place before arranging. Fresh achillea typically lasts eight to twelve days in the vase, making it one of the longer-lasting cottage garden cut flowers.
Dried achillea is quite simply one of the best — the flat-topped flowerheads hold their structure and colour for months, and the warm golden tones of filipendulina types are particularly beautiful in winter arrangements.
Drying achillea — the detail
Achillea dries with extraordinary ease and remarkable results. The key is timing — cut just before the flowerheads reach full maturity, when they are fully coloured but before the tiny florets begin to drop or the colour begins to fade. This is slightly earlier than you might expect: for millefolium varieties, this means cutting when the outermost florets are fully open but the centre is still slightly firm to the touch.
How to Dry Achillea
Strip all leaves from the stems (they go mouldy if left on). Gather in small bunches of five to eight stems — not too many, as good airflow is essential. Tie with elastic bands rather than string, as stems shrink as they dry and loose ties result in bunches falling apart. Hang upside down in a warm, dry, well-ventilated space — an airy shed, spare room or barn is ideal. Avoid damp garages or basements. Achillea dries beautifully in two to three weeks and will keep for one to two years without significant deterioration.
Colours When Dried
A. filipendulina types dry to warm gold and retain this colour exceptionally well — 'Cloth of Gold' dried is one of the finest winter arrangement materials available to the home grower. A. millefolium varieties dry in their own colours but softer — reds become warm rose, oranges become amber, pinks become pale blush. The fading is part of the charm and produces beautifully subtle vintage tones. A. ptarmica dries to cream or off-white and holds the double pompom form perfectly.
Pressing Achillea
Individual achillea flowerheads press beautifully — the flat structure means they lie perfectly in a flower press and dry quickly without discolouration. Pressed achillea is outstanding for botanical art, greetings cards, and resin projects. Press individual flowerheads rather than full stems, and place between layers of kitchen paper to absorb moisture quickly. The tiny individual florets that make up each head create extraordinary detail when pressed.
Ready to discover achillea in your garden?
We've chosen our achillea range with enormous care — selecting varieties that offer exceptional colour, strong first-year performance, superb cut and dried flower quality, and the kind of generous, reliable performance that makes them a fixture in cottage gardens for decades. Whether you're drawn to the warm golds of filipendulina, the vivid crimsons and salmons of millefolium, or the delicate white pompoms of ptarmica — we'd love to help you find your perfect varieties. Sow them this year and you'll be growing them for the rest of your gardening life.
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