Biennial Wormwood: A Rare Native Forb Worth Knowing About
Meet biennial wormwood (Artemisia biennis var. diffusa), a fascinating but elusive member of the Artemisia family that calls the American West home. This little-known native plant might not be on every gardener’s wish list, but its story is worth telling – especially if you’re passionate about preserving rare native species.
What Is Biennial Wormwood?
Biennial wormwood is what botanists call a forb – basically, it’s an herbaceous plant that doesn’t develop woody stems like shrubs or trees. Think of it as a wildflower cousin that completes its life cycle over two growing seasons, which is where the biennial part of its name comes from. Some populations can also behave as annuals, finishing their entire life cycle in just one year.
This plant belongs to the sagebrush family (Artemisia), so you might expect it to have some of those familiar silvery, aromatic qualities that make western landscapes so distinctive.
Where Does It Call Home?
Here’s where things get interesting – and a bit concerning. This variety of biennial wormwood has an extremely limited native range, found only in Utah and Wyoming. That’s quite a small neighborhood for a native plant, which brings us to an important point about its conservation status.
A Rare Find: Conservation Concerns
Before we talk about growing this plant, there’s something crucial you need to know: Artemisia biennis var. diffusa is considered rare, with a Global Conservation Status of S5T1Q. In plain English, this means it’s uncommon enough that plant scientists are keeping a close eye on it.
If you’re thinking about adding this plant to your garden, here’s the responsible approach: only source it from reputable native plant nurseries that can guarantee their stock comes from ethically collected seeds or propagated plants – never from wild populations. Better yet, consider supporting conservation efforts for this species rather than trying to grow it yourself.
Why Might You Want It (Or Not Want It)?
Honestly, there’s limited information available about this particular variety’s garden performance, aesthetic appeal, or specific growing requirements. What we do know is that it’s a true native to the western United States, which automatically gives it points for supporting local ecosystems.
However, given its rarity and the limited knowledge about its cultivation needs, this isn’t exactly a beginner-friendly plant. It’s more of a plant conservation enthusiast choice than a typical garden addition.
Growing Conditions: The Mystery Remains
Here’s where things get a bit frustrating for us gardening folks – specific growing conditions, hardiness zones, and care requirements for this variety aren’t well-documented. This lack of information is actually pretty common with rare plant varieties that haven’t been studied extensively or brought into cultivation.
If you’re interested in plants from the Artemisia family, you might have better luck with more common native species like big sagebrush or other well-established varieties that have proven garden performance.
The Bottom Line for Gardeners
While biennial wormwood (Artemisia biennis var. diffusa) is undoubtedly a legitimate native species worthy of conservation attention, it’s not the most practical choice for most home gardeners. The combination of its rarity, limited availability, and lack of cultivation information makes it more of a specialized conservation project than a garden staple.
If you’re drawn to native western plants with similar ecological roles, consider exploring other Artemisia species or native forbs that are better suited to home cultivation and more readily available from ethical sources.
Sometimes the best way to support a rare native plant is to appreciate it in its natural habitat and support the organizations working to protect it, rather than trying to bring it into our gardens.
