Milkwort, Snakeroot
The two species of polygala which we grow have very different characteristics and places in the garden or glasshouse.
P. chamaebuxus var. grandiflora is a small spreading evergreen shrub with leathery dark green leaves of about 1in length. The flowers are pea-like and appear from the upper leaf axils in April to June. The keels of the pea flowers are purple and the wings are yellow at the ends and white nearer the keels. This is a groundcover plant with an overall height of just 6in or so. It is however fully hardy and suitable for the rock garden or for growing in containers. It does well in a pot in the greenhouse as far as flowering goes but there is no need for it to be kept indoors. Its origin is in the Alps!
P. myrtifolia var. grandiflora is a tall growing but bushy shrub which will achieve 4-6ft outdoors in a sheltered hot spot. At Ventnor Botanic Garden on the Isle of Wight it grows rather taller than this. The pea flowers are in leafy terminal racemes of bright purple flowers. The keel and wings are both the same colour. This is a South African species which, despite its great beauty, can really only be grown outside in the mildest locations. It does however make a good patio plant that must come indoors for the winter. In a relatively frost free greenhouse it will develop quickly into a large shrub so some fairly severe pruning is needed after flowering is over. A liquid feed or two in the spring will quickly get the plant going and you will very probably get several separate flushes of flowers between spring and the autumn.
Both these species of polygala propagate readily from softwood cuttings.
