It’s no surprise that Marchantia polymorpha (liverwort) may be found in every USDA plant hardiness zone, from the tropics to the arctic. This fungus can be found growing in container nursery stock, greenhouses, and regions that are very wet. In order to prevent water from reaching the roots of surrounding plants, the dense mats of liverwort grow on the ground. Preventative measures including natural and chemical herbicides can be used to destroy or kill liverwort weed, which is difficult to eradicate.
Liverwort Spread and Invasion
It is possible to reproduce two different methods when it comes to liverwort weeds. Air currents carry them to other regions where the spores germinate, creating a cycle of re-emergence. Additionally, gemmae, the little, bud-like branches that Liverwort forms in the surface structures it forms in the form of cups, are how it reproduces. Mechanical factors, such as falling raindrops or overhead irrigation, cause the gemmae to dislodge from the plant and create new plants in the surrounding region.
Due to the dangers of gemmae fragments breaking off, hand-pulling the weed is discouraged. Liverwort can be controlled using cultural strategies that take advantage of how the weed develops and spreads.
Before You Begin
Before using compost or mulch or applying any herbicide, whether “natural” or chemical, put on safety goggles, gloves, and other protective clothing. When it comes to horticulture levels of 20 to 30 percent, even home vinegar might cause eye and skin irritations. Only use the product as directed on the label on liverwort or other weeds, and only as directed on the label. Spraying other plants in the garden or greenhouse with herbicides can harm your desired plants as well as the weeds.
When using algaecide or herbicide products near wetlands, lakes, and waterways, use caution. Even though they may kill the liverwort, they can also harm the beneficial algae and other plants in the area.
Growth Condition Control
A variety of factors, including moisture and fertilization, encourage the growth of liverwort, as well. Because liverwort doesn’t have typical or deep roots, it can be killed by not overwatering plants and allowing the surface of the growing medium to dry up.
Cocoa shell mulch, for example, lowers surface moisture while simultaneously preventing the spread of liverwort. Another way to slow liverwort growth is to increase the amount of air movement in the area. Adding fans to greenhouses and indoor spaces can also help to improve airflow. Another approach to keep liverwort from spreading is to include fertilizer into the planting medium rather than apply it topically.
Natural Herbicide Control
Liverwort weeds can be reduced or eliminated by using “biorational herbicides,” which are derived from natural sources. These herbicides are believed to be safe for beneficial creatures and the environment.
Vinegar or acetic acid herbicides, pelargonic acid herbicides, oregano extract herbicides may all be effective in controlling liverwort infestations. Spray a 10% to 20% solution of acetic acid, pelargonic acid, and oregano oil extract with a sprayer. Liverwort is resistant to other natural herbicides like cinnamon-rosemary oil or clove, rosemary-and-thyme oil mixtures.
Chemical Herbicide Control
Several chemical herbicides, such as flumioxazin, quinoclamine and sodium carbonate peroxyhydrate, are effective against liverwort, especially if the infestation is not very large. Flumioxazin is available in granular form; it is only suggested for field or nursery container plants and is not suitable for use in the garden. It is not registered for use in indoor greenhouses as an algaecide, either. Quinoclamine.
Granular sodium carbonate peroxyhydrate dissolves in water to generate sodium carbonate and hydrogen peroxide. Applying 0.1 pound per square foot is all that is required for greenhouse use. It kills the liverwort spores, which is how it gets rid of infestations, and it may work even after the liverwort has taken over.
They can be found in many areas in the garden, but they are most commonly found on the soil and hard surfaces, although they can also grow on plants and do not harm them. Some have a plate-like body, while others have leaves that are flattened to a plate-like shape.
Moist, damp or even wet circumstances and a place out of direct sunlight are usually prerequisites for them to flourish. Even mosses prefer and thrive in these conditions.
It’s common for trees and shrubs to have liverworts growing on them if they are already weak or stressed. Simply put, it could be getting old and ‘beyond its prime,’ or it could have already started dying due of some other issue.
They can cause a slippery surface if they are allowed to grow on walkways, paving, and patios.
Treatment and control
The liverworts that grow on plants have no chemical defenses against them. Physical removal is an option, however it should be avoided because to the potential for further damage to the tree’s bark and branches.
The presence of liverworts can be reduced to some extent by removing any overloaded branches and removing any excess vegetation that grows around the plant.
Enhance the plant’s overall strength by improving its growing environment. Look at the soil and see if it gets too dry or wet in the summer. Increasing the plant’s vigor is made possible by creating favorable conditions for healthy root development. Mulch the soil, water as needed, and feed it once a year in the spring. Strength and vitality can be improved by using a seaweed-based tonic in the form of a foliar feed.
On the soil
This indicates that the soil is compact, airless, and damp for the majority of the year. Liverworts are a good indicator of this condition. Heavy clay soils are the only places where they are likely to be found.
It is possible to remove them, but they will reappear until the soil’s compaction and drainage is improved. Disturb the soil by adding large amounts of organic materials and even sand or grit for gardening.
On hard surfaces
A scrubbing brush or a patio cleaner can usually be used to remove liverworts from a lawn or garden. Physical removal is the only option for pots and containers.
“Is it possible to get rid of Liverwort by burying it?” Russ from Berkley, California, has a question.
Answer: Soil type, depth of soil, and moisture content are all factors to consider. To be honest, I’m a fan of common liverwort (Marchantia polymorpha). Sorry! However, they’re a lot of fun. They are closely related to mosses and a sign that the garden is well-watered, shady, and nutrient-rich. I understand why you don’t want them in your garden because I don’t like them when they’re grown in containers. Here are a few options for getting rid of liverwort.
CHANGE THE SOIL AND SOIL LEVEL
Eliminating liverwort requires decreasing soil moisture and fertility, improving soil drainage and aeration, as well as increasing available light sources. It’s impossible for them to survive in extremes of temperature or humidity. Garden soil that is clogging drains can be lifted and aggregate added to the soil to assist drainage.
REPLANT WITH THE RIGHT PLANTS
Planting native garden plants that can endure damp and shadow in its place can also be an alternative if the liverwort needs to be removed. Two possibilities are presented here.
Flora of California: The wood strawberry grows well in moist soil and prefers shade to partial sun (Fragaria californica). For those who are interested, it can serve as a tasty groundcover.
Upland California wildflower, the idyllwild rock flower (Heuchera hirsutissima), can grow in both moist and dry conditions, and even in partial shade.
Pigsqueak (Bergenia crassifolia) is a lovely shade-loving evergreen perennial that blooms in late winter and early spring with clusters of pink flowers. Moisturized, well-drained soil is ideal for it.
The California Native Plant Society has a plethora of shade-loving plants available for purchase.