Comfrey is a foundational plant in many no till and permaculture gardens because of its ability to break up compacted soil, produce large amounts of biomass, and function as a long term perennial without repeated disturbance. Its growth habits align naturally with garden systems that prioritize soil health, minimal input, and ecological balance. And if you plant the sterile cultivar, it doesn’t even spread that much.
If you’re building your own permaculture system, there’s a good chance you’re considering where comfrey fits in to the mix. Here’s what you should know.
Supporting Soil Life Without Disturbance
In no till gardens, the goal is to avoid soil disruption and allow soil life to thrive. Comfrey supports this approach by developing a root system that improves soil structure without mechanical cultivation. Comfrey roots can extend several feet deep and excel breaking up compaction, creating more soil space to allow water, air, and beneficial microorganisms to move more freely through the soil profile.
Research on no till systems consistently shows that minimizing soil disturbance improves microbial diversity and soil aggregation. For example, a review published in Agriculture, Ecosystems & Environment found that reduced tillage improves soil structure and water infiltration, supporting the principles behind using deep rooted perennials like comfrey in these systems.
We are still learning just how extensive the soil ecosystem is, and how much soil structure plays into fertility. But this is a huge area of research in regenerative agriculture, and one of the most important principles behind designing a permaculture garden that will thrive.
Comfrey as a Biomass Plant
One of the most common ways comfrey is used in no till systems is as a biomass plant. The leaves grow quickly and can be harvested several times throughout the growing season. These leaves are laid directly on garden beds as mulch, where they decompose and feed soil organisms.
Almost any plant can be used as a mulch, but comfrey has an edge over other plants because of its deep root system. Because it can tap into deeper layers of the soil, absorbing minerals where most other garden plants never reach, comfrey leaves tend to be very nutrient rich. Of course, the nutrient density will still vary wildly depending on your location and soil composition.
In permaculture gardens, this mineral recycling can be considered a closed loop fertility system. Comfrey is first planted as a support or companion plant near fruit trees, berry bushes, and perennial vegetables. There, it functions as a living ground cover, protecting the soil surface from erosion and moisture loss. Then it becomes mulch material when cut back, rapidly breaking down and releasing minerals that support surrounding plants without synthetic inputs.
Water Management and Climate Resilience
Deep-rooted plants significantly improve water infiltration and reduce surface runoff, making them a valuable addition to climate resilient garden designs. This is where comfrey can play an important role in water management if you don’t have an existing groundcover. It has large, broad leaves (ideal for shading the soil and reducing evaporation), while having the deep root system that helps improve drainage and reduce runoff by increasing soil infiltration.
Thoughtful Placement in Long Term Systems
Because no till and permaculture systems emphasize long term planning, careful placement of comfrey is essential. We’ve mentioned comfrey’s deep root system a few times now…and the same roots that make it so beneficial also make it difficult to remove.
Luckily, you can keep comfrey from spreading very fast by planting the sterile cultivar, Russian Bocking 14. But it’s still hard to kill. So we recommend putting thoughtful planning into your design, and planting comfrey along garden borders, orchard rows, or designated biomass zones allow you to benefit from its growth without interfering with annual crop rotations.
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.
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