PERENNIALS

What Is A Perennial Plant?

All plants can be divided into three categories: annual, biennial or perennial.

Annuals last for only one year while biennials have a two-year lifecycle. Perennials live for at least three years, usually longer.

The key differentiator, therefore, is that perennial plants have a lifecycle that continues over several years.

Perennial plants are subdivided into two main categories: deciduous and evergreen. Deciduous perennials seem as if they have died by winter but they ‘come back’ the following spring while evergreen perennials remain in leaf throughout the whole year.

Evergreen perennials are often called just ‘evergreens.’ Deciduous perennials are almost as often referred to as just ‘perennials’ though this is not strictly correct.

Perennials – be they deciduous or evergreen – are further subdivided into two main sub-categories; herbaceous plants and shrubs (or shrubby plants).

Essentially, a herbaceous plant keeps a flexible, green main stem throughout its lifecycle, while a shrubby plant soon develops a rigid, brown, ‘woody’ main stem with its branches also often becoming woody as they mature.

Popular UK Perennials

Acanthus / Achillea / Agapanthus / Alchemilla / Alstroemeria / Antirrhinum / Aquilegia / Arum Lily / Asters / Astilbe / Astrantia / Aubrieta / Bamboo / Bearded Iris / Bleeding Hearts / Brunnera / Calceolaria / Camassia / Campanula / Canna / Catmint / Chinese Lanterns / Chrysanthemum / Coleus / Colocasia / Comfrey / Creeping Jenny / Crocosmia / Cyclamen / Dahlias / Daisies / Delphinium / Dianthus / Diascia / Dierama / Echinacea / Echinops / English Lavender / Erysimum / Euphorbia / Feverfew / French Lavender / Fritillaries / Geraniums / Gerbera / Geums / Ginger / Gladiolus / Guernsey Lily / Gypsophila / Helenium / Hellebore / Hemerocallis / Hesperantha / Heuchera / Hibiscus / Hops / Hostas / Hot Lips / Hypericum / Kniphofia / Lavatera / Lily Of The Valley / Lobelia / Lupin / Lunaria / Mexican Fleabane / Myosotis / Osteospermum / Penstemon / Peonies / Periwinkle / Persian Buttercup / Phlox / Phormium / Platycodon / Primrose / Rhubarb / Roses / Rudbeckia / Salvia / Scabiosa / Shasta Daisy / Strawberries / Sweet Alyssum / Thalictrum / Tickseed / Tree Peonies / Valerian / Verbena-Bonariensis / Veronica Longifolia / Viola / Yucca

It is important to recognise, however, that perennial plants can also be herbs or vegetables. You will find plenty of examples of perennial plants in these categories too.

Choosing Perennials

Perennials are a wide group of plants that can differ greatly in their requirements; not all will enjoy the same conditions.

When choosing perennial plants for your garden, decide:

If you want perennials for full sun, perennials for light or dappled shade, or perennials for deep shade.
Whether the plants need a sheltered spot, or can cope with a more exposed location.
The soil type, conditions and pH particular perennial plants will prefer.

Thinking holistically about garden design, it can also be helpful to think about:

When the perennials will be in bloom (and wildlife required for pollination). Try to choose perennials so that you have flowers in bloom in your garden throughout as much of the year as possible.
How you can layer plants in their spacing. Think about planting a wide variety of perennial plants that like similar conditions and complement one another. Remember, companion planting involves choosing plants that aid one another in a variety of different ways, not necessarily just how good they look next to one another.
Integrating perennial flowers with perennial edibles, trees and shrubs. Integration rather than segregation can help you make the most of your space. You can also think about integrating biennial or annual plants with perennial plants in your garden. Self-seeders can be good choices for a low-maintenance perennial bed or border. Biennial foxgloves and annual borage are just two examples of ready self-seeders that could be at home in a perennial planting zone.

Keeping Gardens Low Maintenance

Remember, perennials are plants that will remain in your garden for several years at least, so it is important to place them where they will not be disrupted by the needs of annual plants or crops.

They are ideal for a bed, border or growing area that you would like to maintain but not intensively manage, which is why perennial plants are a good choice for those looking for a low-maintenance garden.

MORE PERENNIAL GROWING GUIDES

pink, orange and yellow flowering chrysanthemums growing in a row in front of a metal gate in pots on a patio outside

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