Propagation - Dividing Plants
Prior to dividing plants prepare the new planting site by removing weeds and digging in liberal amounts of well-rotted organic material, such as garden compost or manure.
Take out a hole wide enough to take the spread out roots comfortably, cover them with soil and heel in.
Finally rake in some bonemeal.
The methods of dividing plants can vary with different types of root system e.g.
Replant the largest ones into their new flowering positions.
If required, plant out the smaller bulbs in a nursery bed to plump up for use in future years.
*Divide and replant snowdrops and winter aconites after they have flowered, and when the leaves are still green.
It is best to divide plants such as these in spring, when the plump buds are beginning to form.
Divide the rootball with a knife saving the parts wih buds on, and discarding the old woody pieces.
If the rootball is quite large and congested divide these by slicing them with a spade, or splitting them apart by means of a pair of garden forks inserted back-to-back then prised apart.
Always select and replant the fresher new growth from the perimeter of the rootball, ensuring that they have at least one bud on each division.
Cut away and discard any old rhizomes (horizontal stems) and only replant young healthy sections.
Ensure that each section/division has some roots and at least one new shoot growing from it.
Prior to lifting cut back stems to about 100mm (4") above ground level,then pull small clumps apart by hand and cut any thick roots with a knife or secateurs.
Large congested rootstocks are more easily divided by either splitting them with a spade,or a pair of garden forks inserted back-to-back then prised apart.
As mentioned previously: only replant the fresher new growth from the perimeter of the rootball, as quite often the centre of the rootball is of poor quality and perhaps a bit woody.
Dahlia and Begonia tubers can be cut in to a number of pieces providing there is at least one eye (growing tip) on each piece.
Although not imperative, the cut surfaces should be dusted with sulphur to protect the inner flesh of the tuber.
Most grasses and bamboos are best propagated by division in mid to late spring or just as the new seasons growth is commencing.
The origin of grasses can often determine the timing of division, e.g
Grasses from cool climates generally come into growth in late winter and flower before midsummer, these should be divided either in autumn or late winter/early spring.
These types of grasses are best divided annually, as this reduces the possibilities of the root sytem becoming congested, this will also help to keep plants growing vigorously.
Grasses from warmer climates generally come into growth in late spring and flower after midsummer and are normally cut back by frosts in winter.
These are best planted or divided in late spring, and generally don’t need frequent division.
The best way to divide grasses is to lift clumps from the ground and split them apart using two forks inserted back-to-back into the centre of the plant.
Some tough roots may require a spade, sharp knife, saw or even an axe to split them apart, but when replanted, they should establish fully during the growing season.
Some small grasses can be split by tearing the clumps apart by hand.
After transplanting the divisions keep them well watered until established.
*Ensure you wear stout clothing and gauntlets to prevent painful cuts caused by sharp leaf edges.
Keep the divisions as large as possible and plant them as soon as possible.
Keep well watered and protect them from strong winds until they have re-established.