Plant Doctor Archive

Dealing with liverwort

I WOULD like to know how to eradicate liverwort from my garden in an area where I have carnations, penstemons, azaleas and a low-growing saxifraga. I tried taking off the first few centimetres of soil, but within a few weeks the pesky liverwort is back. Is there an easy way to get rid of it without harming the plants?

LIVERWORT spores germinate on the soil surface when it stays moist for long periods and once established the mat of liverwort can survive dry periods. The spores blow around in the wind and can travel long distances.

The first line of attack is to try to create conditions that reduce the chances of the spores germinating. First get rid of existing liverwort by spraying or brushing on a solution of Surrender, Hitman or 1 part vinegar to 4 parts water. Or remove the top layer of soil. Once the liverwort has died off (it usually takes only two or three days after spraying) hoe the soil surface until it becomes friable and loose, to encourage it to dry out.

Regular hoeing is often enough to keep liverwort at bay, but if you don't have the time or if the soil won't break up or just simply won't dry out enough, then cover it with a mulch of something like granulated bark, which is naturally open and porous. You could try mixing bark, or coarse sand, with the top few centimetres of soil to encourage better aeration. This should help, but have one of the above sprays ready to apply to any patches of liverwort that reappear. Avoid getting any on your plants though as they can cause damage.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.