Eriogonum — Buckwheat
When the dog days of summer and temperatures of 90° or more hit, it seems that nothing more could possibly bloom in the garden. Flowers are going to seed, the soil is hard and crusted from heat and, with a reduced water regimen, it’s discouraging to keep up with deadheading and wilting. Then, along come the native buckwheats, some dramatic in size and color, surprising the rest of the garden by breaking out in full bloom and asking only for sun, little or no water, and good drainage.
In mid-June, red buckwheat (Eriogonum grande var. rubescens) comes into full bloom. The flower is not red-red but more of a dark pink-to-crimson, rising above gray-green foliage on heavy stems in 1-in. pompons. This buckwheat loves rocky or gravelly open sites and works well as a pronounced punctuation of pink in a mixed border or massed for a more colorful eye-catching effect. A border mixed with the red buckwheat ought to include plants with similar cultural requirements as most buckwheats do not like either heavy shade or soggy feet. The red can get up to 3 ft. high and 6 ft. wide, but not quickly.
The real drama queen of the species is the giant buckwheat, Eriogonum giganteum, commonly called St. Catherine’s Lace. This evergreen shrub is not tidy and definitely requires space, growing 4-8 ft. tall and almost as broad. In bloom, it resembles a huge rounded mound of the common creamy white wildflower, Queen Anne’s lace, but with the flower heads often more than a foot in diameter. Tiny clustered buds slowly mature day by day; then, in late June or early July, there it is in glorious bloom, a mound of intricate, giant lace doilies attracting many species of butterflies, bees, and other tiny beneficial insects, all of which have value not only in our own gardens but in the wider agricultural community as well.
The beautiful gray-green foliage with frosty white undersides looks quite innocent in a 1-gallon nursery pot; however, it is so dramatic and becomes so large, it can serve as a single garden specimen. Give this one plenty of space! It will not work in a small city-lot sized garden unless it is the only plant there. Besides being large, the stems are somewhat fragile, snapping off when a human or animal roughly pushes past it or a hose is dragged over its lower stems. It is happy out in open space but it also mixes well with other native shrubs and many shrub-like perennials.
Buckwheats in general bloom over a long period, eventually fading through shades of tan, beige, camel, and caramel to rust-red. The striking spent blooms stay mostly upright on their mound of foliage. They may be left or pruned back, fresh or dry, to hang upside down for later use in dried flower, foliage, and ornamental grass arrangements.
Propagation by seed is known to be the best way to reproduce these plants as they are prodigious seed producers. Although in a heavily mulched garden, seedlings may be difficult to find. As they are proceeding through their various shades of color toward the end of their peak bloom time, their flowers begin to shatter. Seed may be collected at this point, either by bagging or sweeping up from the ground. They do not require special treatment. Just sow in sand or potting mix kept moist until germination. Then let them dry out between waterings and transplant into larger pots several times during their first year of growth.
One of the great benefits of eriogonums in the garden is that they bloom in summer when many other natives are going into dormancy, and they reward with seemingly never-ending color and interest. Even the foliage without flowers and the more mature gnarly stems are beautiful.