TIME TO DIVIDE HERBACEOUS PERENNIALS

Early autumn is an ideal month to divide the herbaceous perennials of the garden. These are the flowering plants which die back each winter, the roots remaining dormant beneath the soil until the arrival of the following spring, this bringing warmer temperatures which triggers new growth to commence once again.

There are a variety available, producing a beautiful array of colours for the entire summer season. Popular herbaceous perennials are:

- Geranium
- Phlox
- Salvia
- Delphinium
- Aster
- Hostas

The question is why to divide?

Herbaceous perennials can outgrow their space and look rather messy, particularly in the centres and after division, older plants will have an opportunity to rejuvenate.

The garden beds overall may have become overcrowded with plants encroaching on others adjacent to them and without dividing, the following summer the crowding will augment.

It is a productive method to increase the number of plants within the garden and to fill any empty spaces that may exist, this being division is quicker in comparison to growing from seed. It can also save money, if the garden has recently been landscaped then it is an excellent way of adding plants and colour to a newly formed bed.

When dividing, it is advisable to cut down the summer growth of the taller plants near to the base, then with a garden fork gently lift the plant working outwards from the centre as the most vigorous growth is found on the outer areas of the clump. Alternatively, the traditional method of digging deeper around the perimeter of the plant with the intention of
lifting the entire perennial.

A spade can be used on the tougher plants such as Hostas and slicing the clump in two after being lifted.

The smaller plants such as Geraniums, clumps from the outer edges can be lifted using a garden spade, then once lifted, they can be divided again into smaller clumps with the use of a sharp knife.

Perennials with tubers or rhizomes may naturally fall apart when dug, otherwise the tubers are often visible above ground, indicating where to divide.

The divisions should be planted as soon as possible and well watered, part of the clump could be replanted in the same position or a different area of the garden.

It is beneficial to clean the soil from the roots, the advantage being the health of the roots can be seen as one does not wish to replant damaged or diseased roots or tubers. When ever a plant is lifted it is subjected to shock, however, during the dormant time of autumn the shock is less profound. The plants growth cycle after division will be slow as it
recovers from this disturbance. The age old saying being;

         ‘After you divide a perennial, the first year it sleeps, the second it creeps, and the third
        year it leaps’.

Contribution courtesy of Oliver David Cook on behalf of Green Landscapes Cornwall Ltd

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