Dealing with weeds: liverwort

Is liverwort a problem?

Liverworts do not have roots and are therefore rarely harmful to plants, except possibly with tiny or delicate ones such as alpines or dwarf bulbs. On paths or other hard surfaces, liverworts may pose a safety issue as their growth, often in combination with algae or mosses, may make the surface slippery underfoot. When growing amongst or under plants or in lawns, liverwort growth is likely to indicate that the soil is compacted, so there may be insufficient air and water reaching plant roots.

Identifying liverwort

Liverworts form prostrate clumps or little mats of flattened, green leaves. Because liverworts don’t have roots, they can only grow in damp conditions.

The 300 or so species of liverwort that grow in the UK are either thallose or leafy types. Thallose liverworts have a plate-like body of leafy tissue, which is known as the thallos, hence the name. Leafy liverworts may look like mosses at first glance but have small pairs of leaves borne in two ranks, often lobed or serrated at the edges. The fruiting bodies of some types of liverwort may look flower-like in appearance, rounded or umbrella-like in shape and are borne on tiny stems. Common species of liverwort in the UK are Marchantia and Pellia.

How to get rid of liverwort

Organic control

Liverwort is easy to remove as it has no roots. On paths and hard surfaces, vigorous brushing with a stiff-bristled broom is usually sufficient to clear liverwort growth along with moss and plant debris. In borders or anywhere on soil, scrape off using a hoe or trowel. On lawns, use a spring-tine lawn rake to remove liverwort. The debris of liverwort is safe to add to garden compost bins.

Chemical control

Physical removal and tackling the cause of liverwort growth is generally the best option for controlling liverwort.

Prevention of liverwort

The most sustainable way to kill liverwort in the UK is by making growing conditions less inviting. On hard surfaces, discourage damp conditions by allowing good light and air movement around susceptible areas, such as by cutting back overhanging plant growth or sweeping up fallen leaves and debris. Improve compacted soil in borders or pots by adding plenty of well-rotted organic matter like garden compost as a mulch, spread in a 5cm thick layer on weed-free soil, and then worms and other soil organisms take down the compost into the soil which improves aeration. On lawns, aerate to minimise compaction and apply a lawn top dressing in autumn. When buying new plants, remove any liverwort growing on the surface, along with the top centimetre of so of compost, to avoid introducing it to your garden.