Autumn is a moment of renewal for the garden – the soft rotting of summer makes for soil that allows you to move things about and create multitudes. There’s a sweet spot from now until the first hard days of November that allows you to play with how your garden looks.
As well as moving plants, you can propagate them, dividing them into two or three, so that by next summer your single geranium or astrantia might be a drift across your flowerbeds. Not only does this give you plants for free, but it gives you a chance to rethink the design of your garden.
Nothing spells better design than a little careful repetition, a note of yellow flowers played across the garden, a bouncing of interesting leaf shapes from one side to the other. It is all about creating a rhythm that the eye can follow down the garden path or across the borders.
Dividing is a useful method for older plants, too. Often the crown on a mature plant extends outwards, with the newest shoots appearing on the edge and the woody middle less productive. Dividing the plant to promote the edge and lose the central growth is one of the easiest methods of rejuvenating.
This is especially true for older specimens of rhubarb that have become tired and started producing thin stems. Divide it now and see it spring back to life next year.
The general rule of thumb for herbaceous material is that if it flowered in mid-summer, divide before winter; if it flowers in later summer, divide in early spring.
First, dig up the plant. Then slice it into sections from the edge of the crown where the new growth is. Each division needs at least one healthy basal bud or shoot to regenerate. There are a number of ways to do this. You can slice the plant in sections with a sharp spade or an old carving knife: this is a useful method for plants with fleshy crowns such as thalictrum, European primulas, hostas and astilbes, or woody crowns such as hellebores and rhubarb. For more fibrous crowns, such as daylilies, it is easier to use two forks to tease the roots apart. Place the two forks back-to-back in the centre of the plant and lever apart.
Dividing is quite brutal to the plant, but if you sink it into warm, wet autumn soil that is fizzing with activity, the roots will quickly adapt to their new space. You can help things along by adding mycorrhizal fungi such as Root Grow to the planting hole. This will promote a larger root mass. Water in well and mulch with homemade compost.
