This vast genus includes some vigorous and even weedy species, but some slow growing varieties as well, along with a range of good, easy garden worthy subjects. P. amplexi-caule makes a massive leafy bush to 4-5 feet, on which from July to September come countless little spikes of ruby red in the variety P. atrosangiiineum and scarlet in P. ‘FiretaiF. Plants grow into large clumps but should be divided in spring only. P. bistorta superbum grows fairly quickly where moist and in May-June sends up 3 feet poker spikes of clear pink. P. carneum has smaller deep pink pokers, but grows more compactly, flowering in June-July. The affine varieties are useful carpeters, having a fairly rapid surface spread, green in summer, brown in winter. The 9 inches spikes of P. ‘Darjeeling Red’ are in fact deep pink, coming in autumn, but P. ‘Donald Lowndes’ are bright pink and more showy though no taller. These come on and off all summer and both plants are useful amongst shrubs, on banks, or in frontal positions. P. viviparum album is not pure white, but has erect pokers to 15 inches high, capable of makingwhich germinates before it drops. The following Polygonums are choice, but well worth some extra trouble, P. miletti, given moist humus soil and some shade will throw up a long succession of deep red pokers on 15 inches , beginning in June. P. sphaerostachyum makes a dense bushy spread above ground, though the first deep pink spikes begin in late May, soon after new growth begins. From then on flowering is virtually non stop till September making a very bright show indeed. P. sphaerostachyum likes it fairly moist, but does not object to a sunny if moist. Neither of them make a large , and increase from divisions is very tedious, although both are long lived if left alone in the right conditions.
POLYGONUM bistorta superbum