Is Bee Balm an Invasive Plant? Tips for Controlling Its Spread

With its bright unique blooms that attract pollinators by the dozen, it’s no wonder bee balm (Monarda spp.) is a favorite for many gardeners. However this hardy perennial’s ability to spread rapidly has some asking – is bee balm invasive?

While not considered invasive everywhere, bee balm can certainly act aggressively and take over sections of the garden if left unchecked. Understanding its growth habits and how to curb its enthusiasm will allow you to enjoy its benefits without it conquering your yard.

How Bee Balm Spreads

Bee balm is a member of the mint family, and like its relatives it spreads readily via underground stems called rhizomes. The rhizomes creep horizontally producing new shoots and forming expanding colonies.

As the original plant ages over a couple years, it dies out in the center, leaving the new shoots popping up further away. This is why that initial planting spot can end up quite far from where bee balm ultimately ends up growing.

Is Bee Balm Truly Invasive?

While bee balm spreads aggressively, it is not considered invasive in most of its native North American range. The term “invasive” has a specific meaning referring to non-native plants that disrupt local ecosystems.

Since bee balm species like Monarda fistulosa and M. menthifolium are native to nearly the entire continental US, they generally aren’t deemed invasive there. However, they certainly can be opportunistic and spread quickly where conditions allow.

Ideal Conditions Promote Spread

Bee balm’s tendency to spread is most pronounced in ideal growing conditions – namely, loose, moist, fertile garden soil and a site with full sun to part shade.

If your soil is heavy, dry, nutrient poor, or extremely shady, you likely won’t see bee balm colonizing as aggressively. But in an enriched garden bed with dappled sunlight and reliable moisture, it can really take off.

Soil preparation and placement are key factors in managing its spread. Avoid planting bee balm in overly ideal conditions unless you don’t mind it naturalizing.

Controlling Bee Balm’s Spread

If you don’t want bee balm to take over your garden, there are several effective control methods:

• Physical Barriers – Installing rhizome barrier around bee balm patches contains their spread. Use plastic barriers or living barriers like trees, shrubs, or dense perennials.

• Isolated Placement – Give bee balm its own bed away from less vigorous plants, or surround with mowed grass or gravel that keeps it contained.

• Pots and Raised Beds – Growing bee balm in containers above ground or surrounded by raised bed walls also prevents its spread.

• Regular Division – Digging up and dividing bee balm every 2-3 years helps rejuvenate it while controlling its reach. Discard excess divisions or give them away.

• Cutting Back – Removing spent flower stems and cutting bee balm back to the ground after bloom finishes for the season helps curtail its vigor.

• Pulling – Manually digging out and removing unwanted new shoots as they appear is effective for spot control of small colonies.

• Mulch Smothering – Smothering bee balm shoots and rhizomes with cardboard topped with 4-6 inches of mulch prevents its emergence.

With some diligence and the right containment methods, you can grow bee balm without it running rampant through your garden beds. A bit of extra care allows you to enjoy its vibrant, pollinator-pleasing blooms without it becoming a nuisance.

Finding the Right Balance with Bee Balm

For many gardeners, bee balm is a beloved plant that delivers months of bright, unique flowers and attracts hummingbirds, butterflies, and bees by the dozen. However, allowing it to naturalize can quickly get out of hand.

Understanding bee balm’s aggressive spreading habits allows you to plan accordingly and employ control measures as needed. With smart placement and containment, regular division, or spot removal of unwanted growth, you can keep it from taking over.

While it may require some persistence and extra work to keep in check, the rewards of growing bee balm are well worth the effort for most gardeners. Finding the right balance through careful site selection and proven containment strategies allows you to highlight bee balm’s best qualities in your garden.

So don’t be afraid to plant bee balm, even if you’ve heard it can spread aggressively. Armed with the knowledge of its growth habits and effective control methods, you can confidently include this pollinator-pleasing perennial in your yard.