Plant of the Month (July) : Red Buckwheat - Eriogonum grande var. rubescens

July is Butterfly Celebration Month at the Gardena Willows Wetland Preserve and in our garden.  The long days and warm dry weather insure that many insects are flying now – including butterflies.  And nothing attracts butterflies (and other wonderful insects) like a blooming buckwheat. We have several species – and a cultivar – of native buckwheat blooming in Mother Nature’s Backyard right now.

One of the showiest California natives is Red Buckwheat (Eriogonum grande var. rubescens).  While not strictly from our area, it’s such a delightful plant -  and it does so well in local gardens – that we’ve included it in Mother Nature’s Backyard.   This smaller Buckwheat grows wild on the Northern Channel Islands of San Miguel, Santa Cruz, and Santa Rosa  (Santa Barbara Channel Islands chain).   In nature, it can be found on low elevation cliffs and bluffs in island coastal grassland and coastal scrub communities.  Its natural associates include many garden favorites, among them Bright Green Dudleya (Dudleya virens), Sticky Monkeyflower (Diplacus aurantiacus) and Coyote Bush (Baccharis pilularis).

The wild Buckwheats – genus Eriogonum – are flowering plants in the family Polygonaceae (the Knotweed or Buckwheat family).  Most California Eriogonums  are half-woody shrubs (sub-shrubs), although several species  are annuals.   Eriogonum  species are native to North America and  not to be confused with the Asian cereal/flour Buckwheats, which are in a different genus (Fagopyrum).  Our native wild Buckwheats are not the source of buckwheat pancakes – that’s  Fagopyrum – but they are a preferred food source for many a hungry insect.

Red Buckwheat looks quite different from our three local shrubby Buckwheats:  Coastal/Dune Buckwheat (Eriogonum parvifolium), California Buckwheat (Eriogonum fasciculatum) and Ashy-leaf Buckwheat (Eriogonum cinereum).   These three are shrubby in appearance, with many slender branches.  Red Buckwheat is more succulent with short, stocky stems.  In many ways it resembles another Channel Island buckwheat species, Giant Buckwheat/St. Catherine’s Lace (Eriogonum giganteum), albeit much smaller in size.

Red Buckwheat grows 1-2 ft. tall and forms a mounded clump that may reach 3-4 ft in diameter.   Its leaves are spoon-shaped to oval and larger than those of local native Buckwheats (to 1 inch or more).  Like most native Buckwheats, the leaves are covered with downy/cobwebby hairs (trichomes) which may disappear with age on the upper surface but remain as a wooly covering on the underside of the leaf.   This gives the leaves their characteristic colors: gray-green to medium green above and white below.  

Red Buckwheat is evergreen with a little summer water.  However, the plants react to drought in typical Buckwheat fashion.  As the plant dries out, the leaves become less succulent and begin to roll under at the edges (see photo  ).  In a severe drought, plants may even lose most of their leaves.  So keep an eye on your Red Buckwheat.  Signs of drought stress can be a good indicator that a bit of summer water is needed.  

Red Buckwheat is quite drought-hardy when established.  Remember, however, that it hails from islands that get a little more summer fog than we do here in western L.A. County; you’ll need to take this into account when watering.   In local gardens, Red Buckwheat looks best when treated as a Water Zone 2 plant – watered deeply only when the soil dries out (see our posting on Water Zone Gardening – April, 2012 – for more on Water Zones).

Red Buckwheat does well in most garden soils from sandy, alkali soils to clay.  If you have heavy clay that drains slowly, be careful to not over-water in summer, as this will shorten the plant’s life span (they seem to be susceptible to root fungi under these conditions).  On the other hand, don’t be afraid to water in summer if plants are exhibiting sign of drought stress and if you’ve checked to be sure that the soil is indeed dry.  The most accurate way to know if you need to water is to dig down into the soil (below the mulch) and see how dry it really is.  If the soil is dry at a depth of 3-4 inches then it’s time to irrigate Water Zone 2 plants.   Be sure that the soil gets a good soaking, then let it dry out again.

Buckwheats do well in full sun to part-shade, and Red Buckwheat is no exception.  If you garden in a hot inland area, this plant will look better with some afternoon shade.   Other than that, Red Buckwheat is pretty easy to grow.   It thrives on neglect and needs but a light pruning in fall to keep it tidy.  Be sure that you don’t cut back into the woody part of the stem when you prune – it cannot grow back if you do so. 

If you like pink flowers, Red Buckwheat will satisfy your cravings.   The plant has a long bloom season, beginning in mid- to late spring and extending well into summer.   The tiny flowers range in color from brilliant to pastel pink.  Those in Mother Nature’s Backyard are hot pink!   The flowers are arranged in ball-like clusters on rather open flowering stems typical of the native Buckwheats.  As seen in the picture below, there are many flowers per cluster.  Note that the important sexual parts of the flower – the male anthers (pollen) and female stigma – extend beyond the petals.  This arrangement makes it easy for a wide range of pollinators – bees, flies, wasps, butterflies and even beetles - to transfer pollen from one flower to another.

Red Buckwheat is not the best buckwheat for attracting insects in local gardens.  That honor goes to our local shrubby Buckwheats!   But it does attract an impressive number of insects.  Some are drinking nectar or eating pollen (butterflies, flies, wasps & beetles), others (bees) are collecting pollen to feed their young and still others are laying their eggs or preying upon other insects. 

The flowers of Red Buckwheat become lighter – and more orange – through the season.  When the seeds are ripe in late summer, the seed heads will be rust brown.   Some gardeners prefer to remove the flowering stalks once  flowering ceases.  While this may make plants a little neater, we suggest that you let the seeds develop in their natural fashion.  There are at least three reasons to do so: 1) the brown seed heads are actually quite attractive; 2) you can collect the seed to grow new plants – or let the seeds naturalize on their own; 3) the seeds provide food for seed-eating birds. 

Like most native Buckwheats, Red Buckwheat is easy to grow from seed.  In fact, it will likely re-seed in open areas of your garden.  Let the seeds dry on the plants.  You’ll know then the seeds are ready – the dry flower parts and seeds will easy separate from the plant.   Don’t both trying to separate the tiny seed from the chaff.  Just store the lot in a glass jar or paper envelop in a cool dry place until you’re ready to plant.  We like to start Buckwheat in winter or spring in small recycled nursery pots.   Use about a half teaspoon full of seed per 4” pot.  Lightly cover and water in well; keep watered until seedlings emerge.  Buckwheat seedlings are shown below.  If you don’t want to grow them, Red Buckwheat plants are available from many native plant nurseries (see the Where to Buy native Plants page, to the right).

Red Buckwheats make a lovely addition to the home garden.  Their green foliage and neat habit make them a good choice along pathways.  They are also a good filler plant in front of/around larger shrubs.   We like to place Red Buckwheat near a bench or seating area so we can enjoy the flowers and insect visitors.   This plant can be grown in a rock wall or in a large pot/container.  And it looks fabulous massed in a pink/purple garden.   In the picture above, we’ve combined it with white and ‘Island Pink’ Yarrow (Achillea millefolia – see June 2012 Plant of the Month).   This versatile plant is a colorful addition to many gardens – is there a place for it in yours?