Yarrow pruning (Achillea): guide for healthy plants

What is yarrow?

Yarrow (Achillea, also called Schafgarbe) are hardworking perennials with fine, feathery green foliage and flat flower clusters in red, yellow, pink, white or orange. They flower from May through September and are grateful: they tolerate drought, sandy soil, full sun, and grow quickly. But that also comes with a drawback: they become thick and ragged quickly.

Good pruning of yarrow gives you more compact plants, more flowers and longer flowering time. It is simple work.

Spring: April cutback

In April, when you see yarrow is making new growth, prune it back. Remove all dead wood from last year (dark brown). Then cut all green stems back to about 20-25 cm above ground. This looks drastic, but it works.

Your yarrow now grows as a compact, ball-shaped shrub upward.

Summer: pinching for more flowers

This is the secret weapon for more yarrow flowers. In May, as soon as your yarrow starts to bud, prune lightly. Pinch off the top 10 cm of the stems. This takes only a few minutes.

By pinching before bloom, the stems split and you get many more flowers. A plant you do not pinch gives maybe 5-7 flower clusters. A pinched plant gives 15-20.

After the first bloom (around June), when the flowers begin to droop, pinch again. Pinch off all wilted flower clusters and a bit of the top stem. This stimulates a second bloom in July and August.

Autumn: cleanup without cutting back

In September, as bloom declines, you only remove wilted flowers. Leave all green stems standing. These protect the plant against frost. Only cut back in April.

Preventing disease

Yarrow sometimes gets powdery mildew (white powder on leaves) or can rot in wet, dark spots. You prevent this by:

• Good water and air circulation: do not prune too densely
• Full sun: yarrow gets more from it
• Well-draining soil: no wet feet

Division and propagation

After three to four years yarrow becomes large. You can divide it. Dig out carefully. You see a dense mat of roots. With a sharp spade cut this into two to four pieces. Plant separately. This gives more plants.

You can also save seed. Let a few flower clusters die on the plant and set seed. Pick in October, store dry. Sow in March in trays.

Step-by-step

Step 1: Cutback in April

Remove dead wood and cut all green stems back to 20-25 cm. Make sure the plant stays compact.

Step 2: Pinch in May

Pinch off the top 10 cm of all stems. This splits the stems and gives more flowers.

Step 3: Remove flowers after first bloom

In June, as soon as flowers droop, pinch off wilted flower clusters. This stimulates a second bloom.

Step 4: Cleanup in September

Only remove wilted flowers. Leave green stems until April.

Frequently asked questions

My yarrow grows crooked - why?

This can happen in part shade. Yarrow wants full sun. Also too much nitrogen (compost) can lead to weaker growth. Ensure full sun and poorer soil.

Can I prune yarrow in winter?

Not really. It is too cold. Let the plants stand - the dead wood protects against frost. Only cut back in April.

Which Achillea cultivars are easiest?

'Paprika' (orange-red), 'Moonshine' (yellow), 'Cerise Queen' (pink) and 'Walther Funcke' (red) are all robust.

My yarrow does not flower much - what could it be?

Usually lack of sun (it wants at least six hours of full sun) or you are not pinching. Pinching almost doubles the number of flowers.

How often can I pinch yarrow?

As often as you like. The more you pinch, the more flowers. At least twice per season (May and June) is good.

Discover your own garden design

At [gardenworld.app](https://gardenworld.app) you can upload your front yard and see how your yarrow fits - with realistic growth forms and surrounding plantings. Plan and visualise before you pick up the secateurs.