General Perennial Plant Guide

Perennials are plants that will survive for multiple growing seasons, as opposed to annuals, which survive for one season only, and biennials, which have a two year growing cycle. Often, perennials will die back considerably, to ground level or even underground during winter. They will re-grow the following season and in general, displays will increase year on year.

Perennials are a great no-fuss way to bring colour and shape to any garden and form the backbone of a classic “Cottage Garden” style. They are easy to grow and care for and very rewarding – even for novice gardeners. They represent tremendous value for money, as they cover space well, and over a few years can be chopped up or split to create new “free” plants for you to grow or swap.

Perennial Planting

We usually supply perennials either as plug plants or as small, established potted plants. Check the package on receipt to make sure you’re happy with the plants. Treat them as you would any other plugs or potted plants on receipt.

They may look a little worse for wear dependent on their growing cycle and the time of year – and may even look like a pot full of soil with a barely noticeable crown. Please plant them with confidence as this is completely normal during autumn and winter. For oriental poppies, you may even receive these as dormant in the summer as they sometimes do this straight after flowering!

Plant grown-on plants into beds, borders or containers. We recommend larger diameter pots (25cm+) for each plant to allow them room to grow over the years. If growing in borders, space your plants around 45cm apart as a rule of thumb to allow them to grow large enough for maximum impact.

Plant using good quality compost such as our Premium Professional mix, mixed with soil. If you have clay soil it is worth adding some sand/grit to aid drainage. Add some organic fertiliser such as Fish Blood and Bone or well-rotted organic matter to aid growth.

Perennial Care

Perennials are very easy to look after and will provide great displays for many years with minimal effort, the clump of the plant increasing in size. Make sure that they are well-watered during hot or dry spells, but don’t overwater them in wetter weather. Apply a light mulch and feed in early spring.

It is advisable to cut most perennials back in order to keep them neat and tidy, and also to improve their flowering potential. You may choose to either cut them back in autumn, or spring. Cutting back in autumn will make your garden look tidy for winter, but it removes height and structure – which you may want to keep for winter interest, and also to provide shelter for wildlife – in which case cut back in spring.

We’d advise leaving less-hardy perennials such as Penstemon until spring, so that the old stems and foliage can protect the crown of the plant from the worst frosts. When cutting back in spring, cut close to the “crown” of the plant. Take great care to make sure you do not remove any new shoots or damage the crown. The “Chelsea Chop” is often done to taller perennials to improve branching and flowering – done at the time of the Chelsea Flower Show (hence the name!).

Your perennials will continue to grow each year. Dividing them will ensure that they continue to grow healthily and perform year after year. As a general rule, plants should be divided when they’re dormant, in late autumn or early spring. Lift the plant by loosening the soil around the plant, taking care not to damage the roots. Shake off any excess soil, and remove any dead material, then gently divide the roots with a hand fork or spade. Discard any old, woody growth from the centre of the plant and replant the divisions as soon as possible, ensuring that they don’t dry out – to the same depth as the original plant, and with enough room to grow.

Perennials Pot Size

Plant grown-on plants into beds, borders or containers. We recommend larger diameter pots (25cm+) for each plant to allow them room to grow. If growing in borders, space plants around 45cm apart to allow them to grow large enough for maximum impact. Plant using good quality compost.