Not All Butterfly Bushes Are the Same: Understanding Sterile vs. Traditional Cultivars

posted by Colin McInnes
15 Jan

Butterfly bush (Buddleia ssp.) is one of the best flowering shrubs for bringing your landscape to life, as it’s loaded with nectar-rich blooms that butterflies, bees, and hummingbirds can’t resist. But there’s an important detail many gardeners don’t realize…not all butterfly bushes behave the same when it comes to seed production.

Some older, classic varieties of butterfly bush can produce viable seeds and may self-sow in favorable climates. In certain regions and states, that’s contributed to concerns of invasiveness and increasing restrictions on sales, shipping, and planting. The good news is that modern breeding programs have produced outstanding alternatives by hybridizing plants that deliver the color, fragrance, and pollinator power people love, while dramatically reducing (or eliminating) viable seed production.

An Important Note On Wording

In horticulture, the descriptor of sterile is most accurately defined as functionally sterile, meaning the plant has demonstrated no viable seed under typical trial conditions at universities and test gardens. While no plant can be guaranteed sterile in every environment, the varieties listed below in the sterile group are widely recognized and sold as sterile alternatives to traditional butterfly bushes. For ease of understanding, we’ve broken them down into three separate fertility categories: functionally sterile, low-seed / low-viability, and non-sterile varieties.

Group 1: Functionally Sterile (no viable seed)

These are the best choices if you want butterfly bush blooms with the highest confidence that you’re not contributing a possible invasive plant into the landscape.

Lo & Behold® Series

Pugster® Series

Miss Series

Monarch® Series

Humdinger® Series

Garden Debut® Collection

Bloomin’ Easy® Collection

Proven Winners® Collection

Darkest Night™ Butterfly Bush

First Editions® Collection

Group 2: Low-Seed / Low-Viability

These varieties are often excellent landscape performers and may produce very little seed or seed with very low germination. They are best described as “low fertility” rather than “sterile”.

Buzz® Series

Butterfly Towers™ Series

Chrysalis™ Series

Dapper® Series

Flutterby Petite® Series

Butterfly Candy® Series

First Editions® Collection

Group 3: Non-sterile / Viable Seed

These are classic butterfly bushes that can produce viable seeds that can possibly be invasive to some landscapes and gardens. They’re still beautiful, still pollinator-friendly, and still widely grown, but they cannot be listed as sterile or low-fertility cultivars.

Garden Debut® Collection

Proven Winners® Collection

Walters Gardens Collection

Traditional Varieties

If you love butterfly bushes but want to garden responsibly, functionally sterile varieties are the easiest option that offer the “best of both worlds”: big blooms, long season color, and strong pollinator value without the concern of viable seed production. Low-fertility varieties can also be a great choice, especially when you want a specific color, habit, or product line.

When in doubt, we’re happy to help you pick the best butterfly bush for your landscape, your goals, and your state.

Colin McInnes - Sales Manager