I was looking through some nursery cuttings when I noticed something growing across the surface of the media – liverwort.

My first thought was, man, I forgot how cool liverworts are. I’ve learned about them in passing throughout the years, and they are the kind of plant that often goes unnoticed unless you are in very specific situations, like wetlands or production areas of nurseries.

After a second of oogling and making a mental note that these were definitely going under the microscope the second I got a chance, I forced myself to remember that these are pests, and I need to think about how we manage them in production.

That pretty much sums up liverwort in nursery systems. It’s both a fascinating organism and a very real management issue.

What are liverworts?

Liverworts are one of the oldest plant lineages on Earth. They fall into a group called bryophytes, along with mosses and hornworts, and they are considered non-vascular plants.

That means they don’t have the same internal transport systems (xylem and phloem) that most plants use to move water and nutrients. Because of that, they stay small and rely heavily on direct contact with moisture in their environment.

They also don’t have true roots. Instead, they have structures called rhizoids that mainly help anchor them to the surface rather than absorb nutrients.

Life cycle

Liverworts have what’s called an alternating life cycle, meaning they switch between two stages:

• The gametophyte (the flat, green structure you see growing on the media)
• The sporophyte (a smaller structure that grows off the gametophyte and produces spores)

The key thing to understand is that the gametophyte is the dominant stage in liverworts.

For reproduction, liverworts still depend on water. Their sperm are flagellated and need a thin film of water to move and fertilize eggs. This is one of the main reasons they thrive in systems with frequent irrigation or consistently wet media.

In addition to sexual reproduction, liverworts can spread very efficiently through gemmae cups. These are small cup-like structures that produce tiny clones, which are easily dispersed when water splashes across the surface.

This combination of water-dependent reproduction and splash dispersal is what allows liverwort to spread quickly in nursery environments, especially in production when high humidity and moisture are required for seeds to germinate or cuttings to develop roots.

Liverwort in nursery production

Where it shows up

Liverwort is a common weed problem in production nurseries and greenhouses. It is most often found in cool, moist areas such as container-grown ornamentals, propagation houses, ground cloth, and other poorly drained spaces.

These environments provide exactly what liverwort needs to thrive –

consistent moisture, high humidity, and nutrient-rich media.

What it looks like

In nursery settings, liverwort forms dense, low-growing green mats across the surface of container media or nursery floors.

These mats are made up of flattened, ribbon-like structures called thalli, which grow outward and overlap as they spread.

As the mat thickens, it becomes more established and harder to

manage.

Why it spreads so easily

Liverwort spreads rapidly because it reproduces in multiple ways.

It can reproduce sexually through spores (from the sporophyte), which are dispersed by water or wind, and asexually through gemmae (from the gametophyte) that are easily spread by irrigation or rainfall.

Because of this, even small amounts of liverwort left behind can quickly lead to reinfestation.

Why it matters in production

Liverwort is more than just a cosmetic issue – it can directly impact crop performance.

As it forms a dense mat, it can:

• Reduce water infiltration into the substrate
• Interfere with fertilizer reaching plant roots
• Compete with crops for water and nutrients

• 

  Repel water when dry, making irrigation less effective

In many cases, liverwort is also a sign that conditions are staying too wet or nutrient-rich for too long.

Management considerations

Managing liverwort requires an integrated approach. It cannot be effectively controlled with herbicides alone.

Key strategies include:

• Avoid introducing infested plant material
• Improve drainage and reduce over-irrigation
• Increase airflow in production areas
• Adjust fertilization practices to avoid excess nutrients
• Maintain sanitation of pots, surfaces, and tools

While chemical options are available, they are generally most effective when combined with these cultural practices.

A closer look (and why I still think they’re cool)

Now that we know what liverworts are and why we don’t want to see them in production systems, let’s put that all behind us and nerd out on their cool appearance. I took a closer look at the liverwort growing in these cuttings under a microscope, and I even saw something else I always get excited about – mites.

These mites are detritivores, just hanging out and feeding on decaying organic material in the potting mix. They’re part of the micro-ecosystem that exists all around us, even in something as small as this plant liner.

So please enjoy this video I put together of a very common nursery weed – and my very uncommon appreciation for the beauty of this ancient plant and the mites living on it.

References 

Marble, C., Frank, M. S., Laughinghouse, D., Steed, S., & Boyd, N. (2021). Biology and management of liverwort (Marchantia polymorpha) in ornamental crop production (ENH278/EP542). University of Florida Institute of Food and Agricultural Sciences Extension. https://ask.ifas.ufl.edu/publication/EP542 

Preach Bio. (2026, January). All about liverworts: Straightforward guide. https://www.preachbio.com/2026/01/all-about-liverworts-straightforward.html

Saha, D., Lindberg, H., & Sidhu, M. (2020). Identification and management of liverwort in greenhouses. e-GRO Alert.