Yarrow is a herbaceous, perennial flowering herb. This means its foliage dies back in the winter but then the plant re-grows every spring. It come sin a range of colours from white and yellow to orange, pink and dark red. The small flowers are grouped together in flat, clustered heads and are a useful means of attracting hoverflies, ladybugs and parasitic wasps into the garden. All of these insects are great for helping to keep a check on aphids and other small sap-sucking pests. Pollinating bees are also attracted to the flowers as a source of nectar. Plants grow to around knee height - depending on variety – some get larger and some smaller and they are about as wide as they are high.
Companions Yarrow is a great companion plant for many vegetable and fruit plants because it attracts pollinating bees and beneficial aphid-eating insects into the garden. Plant close to brassicas, tomatoes, melons, aubergine, beans, spinach. Yarrow is also beneficial to aromatic herbs like lavender, basil, rosemary, thyme and oregano.
Sow or plant in spring countrywide. Yarrow can also be sown in late autumn and early winter which gives them a useful head start, helping them to establish as young plants so they get off to a quick start in spring.
Yarrow grows well in full sun.
Yarrow is happy in fairly poor to pretty average soil without added fertilliser or compost. Good drainage is appreciated.
In autumn or early spring, sow seeds less than a finger-tip deep in trays or punnets filled with seed raising compost or directly into the garden or proposed container. Ideally seeds should be about a thumb’s width apart. Seeds germinate best in the dark so if you are sowing indoors or in a greenhouse put trays or punnets inside a black plastic bag in a warm spot and check them every day. As soon as shoots break the soil’s surface move them to a light, bright place away from hot, drying air – a windowsill, cold frame or greenhouse would all work. When seedlings get to about a thumb’s length tall, thin them so that plants end up about a hands’ length apart or transplant them into larger individual pots where they can grow till spring. If sowing directly into the garden thin your seedlings so that they can each grow to the spread indicated by variety.
When your seedlings are about a finger’s length in height plant them at spacings that will allow them to reach their indicated spread. I usually dot them around the vegetable garden - planting them between plants and at the corner of beds.
Water young seedlings in dry periods. Once they are established and starting to grow you shouldn’t need to continue with watering unless weather is persistently dry and your soil dries out.
Yarrow should be cut back to ground level in winter once the birds have had their fill from the seed heads, its foliage makes a useful addition to the compost heap. Plants that are more than two years old can be dug up in winter and divided into smaller new plants with the old woody centre of the plant discarded on the compost heap.