How to choose perennials for your garden

What type of soil do you have?

Most perennials grow in well-drained soil that is not too rich in nutrients. Loam soil is the ideal. If your soil is really dry or stays wet for a long time, however, there are still many varieties to choose from.

If you are uncertain about your soil type, a simple-to-use soil tester from the local garden shop will help. One thing to be aware of is that the soil type can vary in different areas of a garden.

A few variety recommendations by soil type:

• Clay soil: Aster, Hosta and Rudbeckia
• Chalk soil: Bergenia, Euphorbia and Verbena
• Moist soil: Hosta, Iris sibirica and Primula
• Dry soil: Campanula, Echinops and Bearded iris

How much light will your perennials get? 

The amount of light available to a plant should contribute to your buying decisions. In order to determine how much light a plant will get, you can simply stand in the desired growing area and take a look at where the sun is at certain times of day.

Most perennials need sun for a good proportion of the day, while some are natural woodlanders and love shady spots.

A few varieties that do well in shade:

• Aquilegia
• Astrantia
• Hosta
• Primula
• Pulmonaria

How tall and wide do you want your perennials to grow?

Perennials come in all shapes and sizes. Tall ones can grace the back of a border, while short, spreading types are great for the very front.

Perennials grow at different rates, so if you plant a tall perennial in front of a short one, the shorter plant will be hidden if they both bloom at the same time.

Variety recommendations by size:

• Edging plants: Bergenia, Prunella and Veronica
• Tall plants: Aconitum, Aster, Delphinium and Verbascum

When do you want your perennials to flower?

I try in my garden to have something in flower throughout the year if possible, but some gardeners don’t spend much time outside until the days get warmer and lighter.

If space is limited, it’s best to consider when you most enjoy the garden. Don’t waste money and space growing early spring flowering perennials that could never be seen.

Variety recommendations by season:

• Spring: Helleborus, Bergenia and Primula
• Summer: Delphinium, Verbascum and Rudbeckia
• Autumn: Aster, Sedum and Chrystanthemum

Which flower colours do you like?

Just as you spend time choosing curtains for your windows, your choice of flower colour is personal. Don’t let anyone tell you which colours do and do not work well together. Go with the colours you love.

Further considerations:

There are other considerations which may help to whittle down your choice. You may want to attract wildlife, for example, or to grow cut flowers. If space is limited, you may want the longest flowering varieties.

Another method of whittling down the variety choice is to select only those perennials that have been awarded the Award of Garden Merit (AGM) by the Royal Horticultural Society. It is a great guide, but not one that is faultless.

Browse the collection of perennials on offer at Claire’s nursery, Claire Austin Hardy Plants. A revised edition of Claire’s Book of Perennials has recently been published. It includes a comprehensive, personal selection of reliable hardy perennials for every gardener and every type of garden. Find it at claireaustin-hardyplants.co.uk.