It took me a while to warm up to a plant named “Spiderwort.” I kept getting this mental image of a cross between the crone in a fairytale (with warts on her nose) and a sinister tarantula. Not appealing!
Of course, worts are small plants used as food or medicinally. It’s not at all the same word as “wart.” And a Spiderwort is no more likely to host a friendly spider than any other garden plant. (Their common name comes from the silk-like threads of hardened sap that seep from a cut stem.)
I was finally won over by the beautiful blossoms and all-around toughness of this worthy garden perennial.
With long, pointed strap-like leaves and flowers with three petals, one could be forgiven for assuming spiderworts grow from bulbs. They don’t. Rather, they’re in the same family (Commelinaceae) as the familiar Wandering Jew houseplants. One has to examine the blossoms to see the resemblance. They are, however, monocots—plants that include most bulbs, lilies, grasses, and other species with parallel veins in their leaves, and flowers with petals in multiples of three.
Our garden plants are usually cultivars of the eastern spiderwort, Tradescantia virginiana. Familiar with that flower, I was surprised to find what appeared to be the same thing growing in our field here in Colorado (left). With a bit of research, I discovered that my wildflower is a different species, T. occidentalis: the Western Spiderwort.
In spite of their delicate appearance, these western wildflowers can take harsh conditions—arid native soils, wind, hail, sudden temperature extremes—in short, all that we Colorado gardeners are so familiar with. No coddling needed here.
The garden variety spiderwort (T. virginiana) is the one most often available for purchase, however, and it needs a bit more attention. Regular water, amended soil (preferably a bit on the acid side), and protective shade will help the plants weather those variables we can’t as easily control. Hardy in USDA zones 4 through 9, at least we know they can handle our cold winters.
That bit of needed attention is well worth the results. Clumps can reach three feet in height, and are adorned in late spring and early summer by intensely purple-blue flowers having three large petals (similar to irises) and decorative yellow stamen. Like daylilies, the flowers only last for one day, but a succession of buds keeps them coming for weeks.
Various cultivars exist, including this one with yellow leaves. Somehow, the yellow color looks unhealthy to me. Plus, I feel that the combination of the yellow foliage with the purple flowers leaves something to be desired. Apparently, many people enjoy the combination, however, as I’ve seen the plants featured at Denver Botanic Gardens. I guess everyone has their own sense of beauty.
Yellow-leafed cultivars aside, if the plants have one drawback, it’s that their foliage dies down after they bloom, leaving a mid-summer gap in the border. The solution is easy—don’t use them in perennial borders. Instead, naturalize these woodland flowers under trees and alongside water features, mimicking their natural habitat.