North America Non-native Plant

Hairy Ironwort

Botanical name: Sideritis lanata

USDA symbol: SILA8

Life cycle: annual

Habit: forb

Native status: Non-native, reproduces and persists in the wild in the lower 48 states  

Hairy Ironwort: A Lesser-Known Annual Worth Considering If you’ve stumbled upon the name hairy ironwort in your gardening research, you’ve discovered one of the more mysterious members of the plant world. Sideritis lanata, as it’s scientifically known, is an annual forb that belongs to a fascinating genus with deep Mediterranean ...

Hairy Ironwort: A Lesser-Known Annual Worth Considering

If you’ve stumbled upon the name hairy ironwort in your gardening research, you’ve discovered one of the more mysterious members of the plant world. Sideritis lanata, as it’s scientifically known, is an annual forb that belongs to a fascinating genus with deep Mediterranean roots, though this particular species has found its way to American soil.

What Exactly Is Hairy Ironwort?

Hairy ironwort is what botanists call a forb – essentially a non-woody flowering plant that completes its entire life cycle in just one growing season. Unlike shrubs or trees that develop thick, woody stems, this little plant stays relatively soft and herbaceous throughout its brief but productive life.

The hairy part of its common name likely refers to the fuzzy texture you’ll find on its leaves and stems, a characteristic that helps many plants in the ironwort family conserve moisture and protect themselves from harsh conditions.

Where You’ll Find It Growing

Currently, hairy ironwort has established itself in Texas, where it grows wild and reproduces on its own without any human intervention. This makes it what ecologists call a naturalized species – not originally from North America, but now calling it home.

The Garden Reality Check

Here’s where things get a bit tricky for the curious gardener. While hairy ironwort exists and has proven it can thrive in Texas conditions, there’s surprisingly little documented information about its garden performance, aesthetic qualities, or specific growing requirements. This isn’t necessarily a red flag, but it does mean you’d be somewhat pioneering if you decided to grow it.

Should You Plant Hairy Ironwort?

Since this species isn’t listed as invasive or noxious, there’s no urgent reason to avoid it. However, given the limited information available about its garden behavior and ecological impact, you might want to consider some well-documented native alternatives that can provide similar benefits with more predictable results.

Native Alternatives to Consider

If you’re drawn to the idea of growing an ironwort-like plant, consider these native Texas options instead:

  • Wild Bergamot (Monarda fistulosa) – Another member of the mint family with fuzzy leaves and excellent pollinator appeal
  • Lemon Beebalm (Monarda citriodora) – A Texas native annual with similar herbaceous growth and proven garden performance
  • Prairie Tea (Croton monanthogynus) – A native annual that shares some of the same ecological niche

If You Do Decide to Grow It

Should you manage to source seeds or plants of hairy ironwort, treat it like most Mediterranean-origin plants: provide well-draining soil, full sun to partial shade, and avoid overwatering. As an annual, you’ll need to let it set seed if you want it to return the following year, or collect seeds for replanting.

Keep an eye on how it behaves in your garden – some non-native plants can become unexpectedly aggressive spreaders, even when they haven’t been officially labeled as invasive.

The Bottom Line

Hairy ironwort represents one of those intriguing garden mysteries – a plant that exists, has found a foothold in Texas, but remains largely undocumented in gardening circles. While there’s no compelling reason to avoid it, there are plenty of well-studied native alternatives that might serve your garden goals better. Sometimes the most responsible approach is to choose the known quantity over the question mark, especially when supporting native plant communities.

If you’re feeling adventurous and do decide to try growing hairy ironwort, consider yourself a citizen scientist and keep notes on its performance. Your observations could contribute to the limited knowledge base about this mysterious little annual.

Hairy Ironwort

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Lamiales

Family

Lamiaceae Martinov - Mint family

Genus

Sideritis L. - ironwort

Species

Sideritis lanata L. - hairy ironwort

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA