Herbaceous Perennials 

Perennial plants are the perfect addition to any garden, providing vibrant flowers year after year. With such a vast selection to choose from, you’ll find options that thrive in every growing condition and bloom throughout the seasons. These low-maintenance plants are incredibly easy to grow, making them ideal for both garden borders and containers. Enjoy beautiful, hassle-free blooms that return season after season.

Before you get started

What are Perennials?

Perennialas are plants that live for several years, available in a wide range of shapes and sizes. These adaptable plants add vibrant flowers and attractive foliage to our gardens, making them a key feature in most borders. While many perennials are hardy enough to survive outdoors throughout the year, others may require protection over the winter to thrive.

The term "perennial" refers to plants that live for at least three years, with some varieties living much longer. Within this category, herbaceous perennials are especially common. These plants lack a permanent woody structure, dying back to the ground each autumn and regrowing in the spring. They can also be planted during summer months too, but will require additional water when planting and check plants daily so they don't be come too dry. This distinguishes them from trees, shrubs, and sub-shrubs, which have more permanent, woody structures.

Perennials are generally classified into two main types:

Herbaceous Perennials – These plants die back to the ground in autumn, but their roots survive through winter, allowing them to regrow each spring. Examples include delphiniums, hardy geraniums, and hostas.

Evergreen and Semi-Evergreen Perennials – These plants retain their leaves throughout the year or for much of it, providing greenery even in the winter months. Examples include bergenias, epimediums, and hellebores.

Whether hardy or evergreen, perennials offer enduring beauty and are a vital part of any garden, providing colour and texture for seasons to come.

Choosing the Right Perennials

Perennials are plants that live for several years, available in a wide variety of shapes and sizes, and they fill our gardens with colourful flowers and attractive foliage. Many are hardy and can thrive outdoors throughout the year, while some may require winter protection. The term "herbaceous perennial" refers to long-lived plants that lack a permanent woody structure (they die back to the ground each autumn), distinguishing them from trees, shrubs, and sub-shrubs.

There is a wide range of perennials to suit any garden style or size, with options for all soil types and growing conditions. Since perennials can live for many years, it’s important to select the right ones for your garden to ensure they grow well and continue to enhance your space for seasons to come.

When to Plant 

Good-sized hardy perennials are best planted outdoors during autumn or spring. These seasons offer the optimal conditions for establishing strong roots.

Perennials are plants that live for at least three years, and the term is often used to refer to herbaceous perennials that grow for many years (for comparison: annuals last one year, biennials two years).

Bare-root plants, young plants, and plug plants are all good options for planting. Plug plants are seedlings or young plants grown individually in small modules, which makes them easy to transplant with minimal root disturbance. Bedding plants and young vegetable plants are often sold as plug plants in various sizes, with smaller ones needing extra care. They typically need to be potted up and grown indoors until they are large enough to plant outside.

Plug plants are generally available in spring and should be potted up immediately into containers before planting outdoors.

Where to Plant

There are perennials to suit all growing conditions and soil types. Always check the plant labels when buying to ensure you place the right plant in the correct location. For more information, see our guide to soil types.

Hardy perennials grow well outdoors all year, but some plants from warmer climates may struggle in winter and require protection, such as the shelter of a warm wall or greenhouse, and well-drained soil.

Perennial Care and Watering

Watering Perennials

Water newly planted perennials regularly during their first year. Once established, most need extra water only during prolonged dry periods. Container-grown perennials require consistent watering during the growing season, especially in hot weather. Groundcover perennials in dry, shaded areas may also benefit from summer watering.

Feeding Perennials

Perennials in borders typically don't require extra feeding, but on poor soil, a balanced fertiliser like Westland Boost or blood, fish, and bone can be applied in spring.

Mulching and Weeding Perennials

Enrich the soil annually by mulching with garden compost or well-rotted manure in spring. Container-grown perennials benefit from a general fertiliser during the growing season.

It’s best to weed between perennial plants regularly, so weeds can’t get established or scatter their seeds. Mulching the border with garden compost in spring will help to deter the 

Pruning 

Herbaceous perennials, which live for three or more years, naturally die back in late autumn as they enter dormancy. Dead stems should be cut back to the base before spring, ensuring they don't hinder the growth of new shoots.

However, leaving stems intact through winter can provide multiple benefits. They offer shelter and nesting sites for overwintering beneficial insects, like ladybirds and lacewings, which help control garden pests. Additionally, seed heads left on plants can add visual interest to the winter garden and provide food for birds.

Consider cutting back plants selectively—removing untidy or diseased growth while preserving stems that contribute to the garden's ecosystem and aesthetics.

Perennials that are liable to flop can be reduced in height in late May to produce stockier plants or delay flowering.