Common comfrey is a not native to the US. But neither are half the plants in your garden, including tomatoes, potatoes, spinach, and carrots!

Just because a plant is non-native doesn’t mean it’s invasive.

While comfrey is a vigorous and long-lived perennial, it is more accurately described as persistent rather than invasive when properly managed. Comfrey only does harm if it is not contained and spreads out of control.

Understanding how comfrey grows and spreads is key to using it successfully in gardens and regenerative systems.

Comfrey primarily spreads through its roots, and can sprout from root cuttings. Even small root fragments can grow into new plants, which is why it can appear difficult to remove once established.

Common comfrey also spreads extensively through seed, making it hard to contain. That’s why we actually suggest that gardeners and permaculture growers stay away from common comfrey. It’s the most difficult type to deal with.

Instead, Russian comfrey spreads less aggressively. Or, even better is the sterile Russian Bocking 14 comfrey cultivar, which cannot spread through seed (only roots). Planting a sterile cultivar can save you a lot of time and trouble later on!

Proper placement is the most important management strategy. Comfrey should be planted where it can remain permanently, such as along garden borders, orchard rows, or designated biomass areas. Avoid planting it in areas that will be frequently tilled or replanted, as soil disturbance increases the chance of spreading root fragments.

For gardeners concerned about spread, physical boundaries such as planting comfrey in defined zones or contained beds can be effective. If you’re growing comfrey for its medicinal benefits instead of using it as a companion plant, you could even grow your comfrey in large containers or grow bags.

Regular harvesting also helps keep comfrey growth contained and productive. Cutting the leaves several times per season encourages controlled regrowth while preventing the plant from becoming overly large. This harvested material can then be used for mulch, compost, or garden teas, turning management into a benefit rather than a burden.

When managed intentionally, comfrey does not behave like an invasive species that overtakes surrounding ecosystems. Instead, it functions as a reliable, long-term perennial that benefits your garden instead of hurting it.

Disclaimer: The information on this page is for educational purposes only. Comfrey is generally recommended for external use only due to the presence of pyrrolizidine alkaloids (PAs). is not recommended to take internally, because it contains pyrrolizidine alkaloids (PAs), which are linked to liver toxicity and possibly cancer. We are not medical professionals, and are not offering medical advice. Please consult your doctor or a medical professional if you have any medical concerns.