Do you know Polygonella?

We have been playing around with the genus Polygonella since 2000, but have still only grown 3 of the 11 US species so far. We are fascinated why these native, highly drought-tolerant members of the buckwheat (Polygonaceae) family aren’t more widely grown.

The common name of jointweed, probably is the biggest factor in their lack of popularity, but then botanist aren’t usually known for their marketing prowess. The plants do have joints, but they are far from being weeds. Polygonellas look like miniature subshrubs of obscure green joints until they burst into flower with hundreds of tufts of small white flowers, that are covered by all kinds of bees.

Below is a current photo of our 4-year-old clump of Polygonella americana. In my humble opinion, honeybee keepers should be planting these everywhere, since they flower during what is known as the “nectar dearth” season, starting here in June. For us, Polygonella americana flowers from June until October. Our plant is growing the un-irrigated crevice garden in a Permatill dominant soil, since great drainage is essential.

Polygonella americana

Long-leaf Buckwheet

We admit to a long-standing case of buckwheat envy. Every visit to the worlds great rock gardens, such as the Denver Botanic Garden, leave us lusting to grow the rock garden genus, eriogonum. We’ve killed many members of the genus, since they truly hate our humid and wet summers. Even our crevice garden was no help in keeping these alive, even including our reportedly easy-to-grow Appalachian native, Eriogonum allenii. After almost giving up several times, we can finally declare success with the Texas native Eriogonum longifolium, from our East Texas botanizing expedition. Here’s our clump in full flower, and quite happy in one of the rock garden sections. Granted, it’s not as stunning as some of the species that thrive in Denver, but hey, we can now check that genus off the list.

Eryngium longifolium