Perennials and Herbaceous Perennials

Helenium Sahin's Early Flowerer

Perennials, from the latin per "through" and annum "year", are plants that live for more than two years, in contrast to annuals that usually germinate, flower and die within one year.

Perennials such as Agave and some species of Streptocarpus that flower and fruit only once and then die are termed monocarpic or semelparous. Most perennials are polycarpic however, flowering for many seasons during their lifetime.

Evergreen perennials such as Bergenia and heuchera retain their foliage all year round.

Deciduous perennials grow and bloom during the warmer part of the year, with their foliage dying back during winter. Herbaceous perennials, which include bulbs, Peonies and Hosta, have stems that die at the end of the growing season. Poppies, available in a variety of colours including orange, pink or white, are a popular example of a herbaceous perennial with their vibrant blooms in June.

Herbaceous perennials are often planted in mixed borders and are ideal for creating a cottage style garden. Combining shrubs, bulbs, bedding and border plants can give year round colour and interest to your garden. A traditional mixed border can be achieved by selecting plants of differing varieties, colours and heights and planting in ever-decreasing heights from the rear to the front of the border.

Planting and Care of Perennials

Good soil preparation is essential for healthy and long-lived herbaceous perennials, and will repay you year after year. Prepare borders by digging to a depth of approximately 20 cm and add well-rotted farmyard manure, general-purpose compost and an all purpose fertiliser such as blood, fish and bone meal.
 
Stand your plants in a container of water for about an hour before planting. Dig a hole twice the size of the pot and fork over the bottom. Try the plant in the hole to make sure it is large enough. Ease the plant out of the pot and gently ease out any tightly wrapped roots. Place the plant in the hole ensuring that the tops of the roots are just below the surface of the soil. Fill in the hole, finishing by firming the soil around the plant with your foot.

After planting your herbaceous perennials ensure the plants are watered in well to settle the soil around the roots. Thorough watering once a week or whenever the surface of the soil looks dry should be carried out for the entire first season, preferably in a cool part of the day to help to establish the plants.

Mulching will not only help to preserve moisture in the soil but will help to reduce weeding.

Once established the border should be fed each spring with a sprinkling of general-purpose fertiliser to help maintain healthy growth.

Taller herbaceous perennials may need to be supported; use canes, purpose-made plant supports or twigs pruned from trees and shrubs in winter to prevent damage.