Cottage garden classic, Achillea, are resilient perennial plants which will grow back in the garden year after year, forming a clump over time which produces a bounty of flower stems in various colours. They're low-maintenance once established, although they will need care at first to help them settle in, especially those which are supplied as bare roots. Here's how to give them the best start..

How to plant:

— Plant as soon as possible after delivery. Soak bare roots in water for 3-6 hours prior to planting. Achillea plants supplied as root balls will also require watering straight after delivery. You can plant Achillea in spring or autumn but they must be planted in the same season as supplied, ideally within a week of delivery while they're fresh.

— Achillea are supplied as either root balls (with soil on the roots) or as bare roots (without soil). Achillea supplied as root balls are slightly more established and can often be plants directly into a clear space in a well cultivated border, depending on the soil type, moisture levels and growing conditions in the border. Avoid planting them into a space which will become over-crowded by more established plants because new plants will struggle to compete.

— Achillea supplied as bare roots should be potted up into individual 15-20cm pots with multipurpose compost, this will give them an easy start and then they can be transferred into a border after a few months once they are more established.

— Plant bare roots and root balls so that the root system is fully submerged in the compost, leaving the buds/crown just below the surface. Any young shoots/leaves or stems should be left exposed above the soil surface. Water well after planting and continue watering regularly whenever the soil starts to dry out.

— If planting Achillea root ball plants directly into a clear space in a border, choose a sunny position with rich, free-draining soil and space the plants 15-20cm apart to form a group. Add multipurpose compost to each planting hole to help the new roots grow and water well afterwards. Mark with a plant label or cane so you can identify and monitor the new plant in the border and keep the area clear of weeds. If you are planting in containers or potting up bare roots to grow-on, you should use multipurpose compost and a 15-20cm pot for each plant.

— Achillea are sun-loving plants and are well adapted to drier conditions. They don't like to be in wet soil all the time, but do water immediately after planting and continue watering regularly in the first spring and summer when the soil starts to feel dry 3-5cm below the surface.

— Achillea are hardy perennials, there is no need to protect them from frost over winter although newly-potted plants may need some cover during cold snaps.

—There should be some buds or shoots visible on the plants/bare roots when they are supplied in spring. After planting, the buds or shoots should continue to grow and produce leaves. When planting in autumn, they may not yet have visible buds or shoots but may produce a small amount of growth before becoming dormant for winter. They will resume growing in spring. If planting in spring, shoots or buds are normally visible on arrival and they should continue to grow and produce leaves through the summer season. They may not flower in the first year.

Aftercare

—The flowers are long lasting. When they have faded you can deadhead them and then in late summer/autumn you can cut the stems right down at around 5cm from the ground.

—Over time, the root system will spread to form a clump. Large clumps can be lifted and split into smaller clumps between autumn and early spring. Each section can be planted with around 20cm of space between them to allow room for further growth, or each section can be planted in different areas of the border to form additional clumps.

Read further general instructions about planting bare-root perennials