Shiraz Web Publications UK - Advice on Dividing Herbaceous Perennials

Dividing Herbaceous
Perennials

HomePage		Dividing plants is perhaps the easiest and quickest method of propagating: - Non Woody Herbaceous Perennials; Grasses; Ferns; Most Alpines; and Aquatic Plants. Most of these plants are mat- or clump-forming, and as they grow the centre of the plant becomes congested, the plant loses vigour and begins to die. Thus division to increase stock of a plant is not simply a useful means of propagation but an essential requirement if the plant is to be preserved. The best time to lift and divide a plant is during the Spring before the plant has started into growth, although for fully hardy plants division can be accomplished at any time in Autumn once the plant has become dormant. When dividing a plant always look for natural divisions in the clump. Many plants will naturally have a distinct centre with offsets, which can be parted from the parent plant with little effort. Replant only the new plants produced by the crown.
Propagation
Techniques
Cuttings - Softwood
Cuttings - Hardwood
Cuttings - Root

Propagation of Bulbs
Propagation of Lilies
Division of Herbaceous Perennials
Division of Bulbous Plants
Growing Plants From Seed
Layering
Micro-Propagation



Equipment
The Essential Kit You Will Need

Large clumps are best divided using two forks and a piece of timber. Push the two forks into the clump 'back to back' at the point where it is intended the clump should be divided, then pull the handles of the two forks together, this should separate the clump at the bottom. Now insert the piece of wood between the tines of the forks underneath the clump and pull the fork handles apart separating the top of the clump. Complete separation of tough clumps can be achieved using a saw, sharp knife or secateurs.

Fibrous rooted plants can usually be separated by hand, but particularly tough sections may require a knife or secateurs to complete the task.

Some plants with particularly woody stools such as pampas grass cannot be easily divided. I have always found that a carpenters saw, hammer and chisel are effective in obtaining new portions of such plants for propagation purposes.

Rhizomatous plants like flag Irises naturally produce offshoots which are easily separated from the old root, all that is required is a sharp knife.

Some plants like peonies produce large fleshy crowns with very obvious buds. Again it only requires a sharp knife to divide the crowns.

Like all other forms of propagation, the biggest reason for failure of divided plants is poor hygiene. Newly exposed cut surfaces on roots or portions of a crown provide the perfect entry point for fungal, viral and bacterial infections. Thus it makes sense to wash as much soil as possible from crowns before cutting them, and after dividing, to dust the open wounds with a good powdered fungicide. More fibrous rooted plants would benefit from immersion in a liquid fungicide.