MANY spring flowering perennials can be divided and
replanted, a couple of weeks after their blooms have
Of course you don't need to do this with all of them, just
the ones which are getting too big for their boots or didn't
flower as well as usual. Older Primula, Doronicum, Aubrieta,
Dicentra are but a few candidates. How do you divide? Well
if you've a plant with fibrous roots, maybe may need two
forks driven down back to back in the centre of the clump,
then carefully prised apart.
For those perennials with fleshy crowns, dig up the whole
mass and use a sharp knife to cut it. Each new section needs
to have a bud and plenty of roots to ensure success.
Iris are one group of perennials that especially benefit
from division, as they grow from their edges leaving a woody
old interior. You really should do this every three or four
years, again a couple of weeks after flowers have finished.
Dig up the entire clump, cutting off fresh pieces 4-6 inches
long with good roots and leaves. Prune off the. top of the
leaves too, as this stabilises the new plant. Then set the
new rhizome on good soil and compost, which must be well
drained. Iris do best on dry soil, and the rhizome shouldn't
be completely covered - just ensure the roots are well
Keep an eye on feeding your later flowering herbaceous stock
like Dahlias; they are very hungry plants at this tune of
There's a few local gems to look out for, now in flower. The
Roses 'Sam McGready' and the compact, double scarlet
flowered 'City of Belfast' (look out for them in Sir Thomas
& Lady Dixon Park ) and the Aconitum 'Newry Blue', not to
mention the Escallonia 'Donard Seedling', 'Donard Radiance'
and 'Pride of Donard', originally cultivated on the sunny
slopes of Slieve Donard near Newcastle.