Growing Herbaceous Perennials
Herbaceous perennials like lupins, hostas, poppies, Michaelmas daisies, and delphiniums are a mainstay of English garden borders and beds. They bring a garden to life with vibrant splashes of colour and add structure to borders. With so many different perennials to choose from, it is easy to find a perennial for a spot in your garden, whether you need a plant that’s low-growing or one that’s tall. With the right mix of perennials, you can look forward to a garden full of interest and colour all year round.
Table of Contents
When to Plant
The best time to plant perennials is in the spring or autumn. This will ensure the best possible outcome as soil conditions are optimal and there’s very little chance of frost or a heatwave. If you are planting perennials in containers and tubs, they can be planted all year round with the right care and attention.
Preparing the soil will help your new perennials get established and grow into healthy, strong plants. Dig over the soil in beds and borders. Remove weeds and fork the soil so it is loose enough for roots to get established and grow.
Water the plants well before placing them in the ground or container. If a plant looks potbound when removed from its container, gently tease the root ball out. Place plants in the ground, backfill the hole and press down the loose soil firmly with your hands. Give the new plants good water.
Styling Perennial Borders
Perennials are traditionally planted in a border or central bed. They are often planted in front of a hedge, wall, or tree in a border. When designing a planting scheme, focus on colour, shape, and height. Groups of five or more plants help to create waves of colours. Take note of the spread of a perennial and make sure you plant individual plants close enough together that space will eventually be eliminated.
Try and mix up the colours a bit. Too much of one colour can be boring. Pay attention to leaf colour too, as your plants won’t be in flower all year round. Most perennials only flower for a few weeks, so plant carefully to ensure you have a good mix of interesting textures and leaf colours once the flowers have died off.
Plant the smallest perennials at the front of the border or around the edge of an island bed, and the tallest plants in the centre.
Pinching Growing Tips
Remove dead flowers all through the growing season to keep the plants flowering. At the end of the growing season, remove any dead foliage and flower stems.
Lifting and Dividing Perennials
Once perennials are well established, there is a danger that the roots can become congested. If this happens, the plant will suffer and may even die. The best way to tackle the issue is to lift the plant and divide it into several smaller plants. This not only improves the health of a perennial but also means you have more plants to fill out other areas of your border.
Only dig up and divide perennials once the growing season is over. This is usually between late autumn and early spring. Divide root clumps carefully, making sure each plant has 3-5 root buds. Any dead sections of the plant should be thrown on the compost heap. Plants with more roots will get established faster. Larger plants can be divided using two garden forks to force the root clump apart. Otherwise, do it by hand or with a hand fork.
Make perennials the mainstay of your garden planting scheme and you can enjoy year-round colour.