Power Plant
Red hot pokers are not what they used to be
By Rachel Foster

I’ve been growing perennials for years, and I’ve learned a thing or two about what I like. Leaves matter. Texture and form are as important as flower color. I can live without plants that require feats of engineering to keep them upright, and I appreciate plants that flourish for several years without division, while keeping more or less to their allotted space. Attracting hummingbirds is a nice bonus. Kniphofias, or, as they are inelegantly called, red hot pokers, fill all or most of these requirements, and their distinctive flower spikes packed tight with tubular flowers contribute a special energy to perennial groupings. Foliage varies from stiff, arching sword shapes to narrow and grass like. The tidiest growers also look splendid growing among low shrubs and conifers. 

Flowers go in and out of fashion. Kniphofias, like canna lilies, are enjoying a revival, and many varieties are available if you hunt for them. The blazing red and yellow bi-colors of classic red hot pokers — or torch lilies, if you prefer — are still around, but you can also find pure light yellow, cream, chartreuse and coral red “pokers” ranging in height from 15 inches to 4 feet. Taller kniphofia varieties combine well with dahlia, phygelius, rudbeckia and yarrow. Those that bloom in late summer are great with asters and ornamental grasses. I like to plant the smallest varieties near the edge of the border, among lower growing plants like heuchera and hardy geranium, where the whole plant can be admired. 

Among my favorite kniphofias are: ‘Primrose Beauty’ (three-foot spikes in cool, light yellow, blooms mid to late summer); ‘Sunningdale Yellow’ (a little taller, blooms in early summer, in a color that leans slightly towards gold); and ‘Shining Scepter’(also early, a stunning, luminous light orange). All these look fabulous with blue or purple flowers. Try early bloomers with salvia ‘May Night’ or emerging from a froth of catmint.  

‘Coral’ was the name attached to my earliest-blooming poker, but I have never been able to confirm a cultivar by this name, so perhaps it was merely a descriptive. This one grows about 2 feet tall, with narrow leaves and a prolific crop of spikes. It is typical of hybrids from Kniphofia triangularis, including many with flowers in soft shades of coral, apricot and cream. ‘Nancy’s Red’ is a small, graceful poker with narrow foliage and flowers of deep coral red, blooming in late July. I like to see it in front of Aster x frikartii or the small shrub caryopteris (bluebeard). 

A nameless favorite that blooms quite early in light coral was one of three pastel shades that that I selected from seed grown plants of the strain ‘Flamenco.’ Advertisements for Flamenco always seem to stress their brilliant reds and yellows, but they seem to cover the entire range of kniphofia shades, including many pastels. If you have room to raise a number of them from seed you’ll find some lovely things.

All kniphofias bloom best in full sun, with four or five hours of sun being a reasonable minimum. Beyond that, I’ve seen a lot of contradictory information about what kniphofias need. Perhaps that means they are not very fussy. I’ve grown them for years in water-retentive soil that is often wet in winter, though never water-logged. Only ‘Little Maid,’ an adorable ivory miniature named by the great British plantswoman Beth Chatto, flatly refused to grow for me. In retentive soil, established kniphofia plants are reasonably drought tolerant. In lighter soil, they’ll need ample water to bloom well. Feed plants each spring and protect them from snails, which can spoil developing flower spikes. 

Winter makes a mess of kniphofia leaves. I once asked the O’Byrnes, whose wonderful borders at Northwest Garden Nursery are beautifully kept, when they cut back their kniphofias, Ernie said, “We cut them down after a frost knocks them back, or anytime in a mild winter. It doesn’t seem to matter much when we do it.” With that in mind, I usually leave mine until the first spring clean-up. Some people shorten the leaves by half in fall and bundle them together over the crown. Be sure to cut off the old leaves before new growth begins in spring.

If you are visiting gardens this summer, watch out for these fabulous South African natives. If you would like to see pictures of many kniphofia species and hybrids, visit www.theafricangarden.com ew

Rachel Foster of Eugene is a writer and garden consultant. She can be reached at rfoster@efn.org