GARDENING: Build up your stock through regular division

Successive ground frosts have persisted throughout daytime recently, holding the garden soil in their vice-like grip, and thwarting our plans to make changes to certain hardy border perennials. But every cloud has a silver lining.

Thursday, 4th February 2021, 12:00 am
Geranium `Johnson`s Blue.`

The rock-hard surface has allowed access in between trees and shrubs without harming soil structure. So, we were able to complete their winter pruning. Thankfully, such setbacks are overcome because time is on our side. A broad swathe of perennials remain in a semi-dormant state, at least until March arrives. Our plans will spring into action immediately the frost goes.

Although this involves extra work, leaving the plants identified as they are going into a new growing season is not an option. Because they include vigorous herbaceous perennials which are encroaching on others. Besides which, the bonus for dividing such subjects into sections is more free plants. Whenever buying a single herbaceous perennial plant, think of the potential for raising identical offspring once it has matured and needs splitting into sections.

Where there’s plenty of growing space (and money) available, the ideal is to plant floral beauties of your choice in groups of three, five or seven, thus creating impressive banks of colour. However, the more satisfying approach, is to build the stock up through regular division.

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Herbaceous perennials we need to access once frost recedes include the popular, tall Helianthus Lemon Queen which is vigorous, bordering on invasive. It has already been divided once but needs a second visit. As with most herbaceous types, the centre becomes woody and less productive. It’s the peripheral rooted sections that are taken for their vigour.

Hardy geraniums, Johnson’s Blue and Rozanne especially, are up for division. So too the cone flower (Rudbeckia Goldsturm), helenium and achillea. Collectively they offer continuity of colour from midsummer into autumn, and work like a magnet in attracting butterflies and bees.

Last week I noticed a blackbird feasting on berries of the black lace plant (Ophiopogon planiscapus Nigrescens). Now there's a good reason to continue spreading it around the garden and keep these territorial birds wide apart!