North America Non-native Plant

Mullein

Botanical name: Verbascum ×kerneri

USDA symbol: VEKE2

Life cycle: biennial

Habit: forb

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

Kerner’s Mullein: A Rare Hybrid Worth Knowing About If you’ve stumbled across the name Verbascum ×kerneri while browsing plant catalogs or botanical references, you might be scratching your head wondering what exactly this plant is all about. Don’t worry – you’re not alone! This particular mullein is something of a ...

Kerner’s Mullein: A Rare Hybrid Worth Knowing About

If you’ve stumbled across the name Verbascum ×kerneri while browsing plant catalogs or botanical references, you might be scratching your head wondering what exactly this plant is all about. Don’t worry – you’re not alone! This particular mullein is something of a botanical mystery, even to many seasoned gardeners.

What is Kerner’s Mullein?

Verbascum ×kerneri, commonly known simply as mullein, is a biennial forb – which is just a fancy way of saying it’s a non-woody plant that completes its life cycle over two years. Like other forbs, it lacks the thick, woody stems you’d find on shrubs or trees, instead producing softer herbaceous growth that emerges from buds at or near ground level.

This particular mullein is actually a hybrid (notice that little × in its scientific name), which explains why information about it can be surprisingly scarce. Hybrids often occur naturally when two different mullein species cross-pollinate, creating offspring with characteristics from both parents.

Where Does It Grow?

Kerner’s mullein has been documented growing in three states: Iowa, Michigan, and Wisconsin. This limited geographic distribution suggests it’s either quite rare or simply hasn’t been widely studied or cultivated. As a non-native species that reproduces on its own in the wild, it has managed to establish itself in these areas without human intervention.

Should You Plant It?

Here’s where things get a bit tricky. While Verbascum ×kerneri isn’t listed as invasive or noxious, the limited information available about this hybrid makes it difficult to recommend for most gardeners. Its rarity and the lack of readily available seeds or plants mean you’re unlikely to encounter it at your local nursery anyway.

If you’re drawn to mulleins in general (and who isn’t charmed by those towering flower spikes?), you might want to consider native alternatives that provide similar visual appeal while supporting local ecosystems:

  • Great Mullein (Verbascum thapsus) – though this is also non-native and can be weedy
  • Wild Bergamot (Monarda fistulosa) – a native alternative with tall spikes
  • Culver’s Root (Veronicastrum virginicum) – produces similar tall, white flower spikes
  • Wild Senna (Senna hebecarpa) – offers height and structure in native plant gardens

Growing Conditions and Care

While specific growing requirements for Verbascum ×kerneri aren’t well-documented, most mulleins share similar preferences. They typically thrive in:

  • Full sun locations
  • Well-draining soils (they often struggle in heavy, wet conditions)
  • Poor to moderately fertile soil
  • Areas with good air circulation

As a biennial, this mullein would spend its first year developing a rosette of leaves close to the ground, then send up its characteristic tall flowering spike in the second year before setting seed and completing its life cycle.

The Bottom Line

Verbascum ×kerneri remains something of an enigma in the gardening world. While it’s not problematic enough to avoid entirely, its rarity and our limited understanding of its specific needs make it more of a botanical curiosity than a garden staple. If you’re interested in adding height and structure to your garden with mullein-like plants, you’ll likely have better success (and do more for local wildlife) by choosing well-documented native alternatives.

Sometimes the most interesting plants are the ones that keep a few secrets, and Kerner’s mullein certainly fits that description!

Mullein

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

Scrophulariales

Family

Scrophulariaceae Juss. - Figwort family

Genus

Verbascum L. - mullein

Species

Verbascum ×kerneri Fritsch [phlomoides × thaspus] - mullein

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