Monty Don shares his simple tips for dividing herbaceous perennials

Now's the time to split herbaceous plants to rejuvenate growth and boost their flower power. The celebrity gardener explains how to divide and conquer

Monty Don tips for dividing perennials
(Image credit: Leigh Clapp)

March is a time for new beginnings in the garden and, as TV gardening guru Monty Don explains, nothing likes a new start quite like a herbaceous perennial. And that, explains the Gardeners' World expert, means lifting and dividing them to give them a boost and create many more healthy new plants. 

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'It is worth doing this to all herbaceous perennials every three to five years,' writes Monty Don in this month's advice column on his website

Herbaceous perennials are the reliable, dependable plants in our flower borders. They die right down to the ground in autumn and winter, but the roots remain alive and send up new stems and top growth in spring. They provide a wealth of flowers through the summer for seemingly little effort in return. 

Monty Don tips for dividing perennials

(Image credit: Leigh Clapp)

To keep the new season's growth healthy and full of flowers, established herbaceous plants should be divided. 

And the time to lift and divide herbaceous plants is now, when the new growth is just starting to appear. 

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Monty Don tips for dividing perennials

(Image credit: Getty Images/mikroman6)

It couldn't be simpler to lift and divide herbaceous perennials and the rewards are well worth the small amount of effort. 

'Dig the whole plant up and discard the centre section to the compost heap, replanting the more vigorous outside parts of the plants in groups which will grow together to make one large plant,' writes Monty Don.

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Monty Don tips for dividing perennials

(Image credit: Leigh Clapp)

'Dividing herbaceous perennials is part of the upkeep of any herbaceous border,' explains the presenter in a clip from Gardeners' World in which he demonstrates how to lift and divide vigorous Acanthus spinosus, chopping through it with a spade to produce multiple new plants that can be grouped or distributed throughout the garden. 

Perennial geraniums in particular divide up very readily, explains Monty Don, as he demonstrates how they can be gently pulled apart by hand. The new geranium plants can also be replanted in a group, 'which will give them new energy and new vigor and therefore much better flowering,' he says. Alternatively, he says, the new plants can be moved to another spot in the garden or shared with fellow gardeners. 

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Monty Don tips for dividing perennials

(Image credit: Leigh Clapp)

From all the plants in your garden, how do you know what is a herbaceous perennial? They are the plants you find in most herbaceous borders, the perennial geraniums, delphiniums, salvias and heucheras, to name but a few.

Many herbaceous perennials will reappear each year for up to 10 years, others are more short lived and will last not much more than three years.

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However, the one thing every gardener can do to rejuvenate herbaceous perennials is to lift them and divide them. This will make a big difference to how vigorously the plants grow and flower, and it will even help restock the flower border, too. And if it's extra plants you're after, then you can divide herbaceous perennials more frequently – every two years is fine. 

Karen Darlow

Karen is the houses editor for homesandgardens.com and homes editor for the brand’s sister titles, Period Living and Country Homes & Interiors, and an experienced writer on interiors and gardens. She loves visiting historic houses for Period Living and writing about rural properties for Country Homes & Interiors, and working with photographers to capture all shapes and sizes of properties. Karen began her career as a sub editor at Hi-Fi News and Record Review magazine. Her move to women’s magazines came soon after, in the shape of Living magazine, which covered cookery, fashion, beauty, homes and gardening. From Living Karen moved to Ideal Home magazine, where as deputy chief sub, then chief sub, she started to really take an interest in properties, architecture, interior design and gardening.