Perennials are one of the most useful plants in the garden, providing colourful garden flowers, year after year. Unlike annuals which flower, set seed and die back within 12 months, perennials live for several years.

Perennials may be either:

Herbaceous – they die back in autumn and winter before regrowing in the spring to flower in the spring and summer, e.g. Geranium, Salvia

Evergreen - they keep their leaves all year round, e.g. Euphorbia, Heuchera

Perennials come in an extensive range of different sizes, colours and flower types and different perennials thrive in different aspects and soil types. Many of them are also attractive to pollinators so whatever theme you envisage for your garden, make sure you include some perennials!

Caring for Perennials

Perennials purchased in pots can be planted pretty much at any time except when the ground is very dry or frozen, but the best times are autumn and spring. As the plants will be growing for several years it’s worth improving the soil with well-rotted organic matter or soil conditioner. The well-known phrase of ‘right plant, right place’ is particularly apt for perennials so it’s important to ensure that they are planted in the right situation. Some of them thrive in sunshine, others in shade and some of them cope better with different soil types.

As perennials do much of their growing in spring, it’s essential to feed them in springtime with a general slow-release fertiliser. During the flowering season remove any dead and faded flowers to prolong the flowering. As with all plants in containers, any perennials in containers should be watered regularly – perennials planted in the ground may also need some watering in dry soils and hot conditions.

Dividing Perennials

After 3 to 5 years, perennials tend to form large clumps so dividing perennials regularly will ensure healthy, vigorous plants that continue to perform year after year. Lifting, dividing and replanting them not only rejuvenates the plants but provides you with more free plants for growing in the garden or giving to a friend!

The best time to divide most perennials is in early spring (before new growth) or late summer/early autumn (after flowering), allowing plants to establish roots before extreme weather. 

Our Favourites

With so very many perennials available, it’s hard to choose our favourites, but there are some that we just don’t want to be without!

Erysimum Bowles’s Mauve (Perennial wallflower) – one of the longest-flowering perennials, bushy and vigorous with long spires of masses of deep mauve flowers from late winter to summer (and often into autumn too). Easy to grow, loved by bees as well as humans. Up to 75cm high x 60cm wide.

Salvia nemorosa Caradonna – classically beautiful clump-forming Salvia with masses of vibrant violet-blue flowers on rich, purple-black stems above sage scented green leaves. Flowers all summer into autumn. Much loved by bees. Approx 45cm x 45cm.

Erigeron karvinskianus – versatile, attractive, low-growing spreading perennial with small daisy type flowerheads opening white, turning to pink. Flowers all summer long. Thrives in full sun and tolerates poor soil. Self seeds and is particularly useful for cascading over walls and steps and softening the edges of pathways. Up to 30cm high x 100cm wide.

Helleborus niger Christmas Carol – clump-forming semi-evergreen perennial with stunning large white flowers in winter and early spring. Prefers humus-rich soil in partial shade. Useful as a winter food source for pollinators. Up to 30cm high x 40cm wide.

Heuchera – available in many different varieties with many different vibrant leaf colours. Low maintenance and easy to grow, they thrive in partial shade and the leaves provide useful colour in the garden, all year round. Delicate flowers are attractive to pollinators. Up to 40cm high x 30cm wide.