How to remove ground elder organically

I love lots of plants people call weeds (see my book) but there are some plants that can be problematic in gardens and worth removing, such as ground elder, Aegopodium podagraria. Ground elder is a beautiful plant, with attractive green leaves and white umbels of flower that look like short cow parsley in early summer. In our new garden we have a 4m x 5m patch of ground elder which some might see as a bad thing, but I’m over-the-moon as I can now test and demonstrate what organic methods work to remove it (or not!)

The problem with ground elder

Early spring shoots and roots of ground elder, Aegopodium podagraria. The roots spread quite shallowly horizontally beneath the soil surface and can regenerate from the tiniest fragment.

Unfortunately, ground elder spreads by underground rhizomes, horizontal roots with shoots, that spring up creating a dense mat that blocks out many plants of the same size. Eventually it will kill other perennials by taking light, water and nutrient, creating a monoculture of less value for wildlife and less interesting for us. It is a vigorous grower that will shoot from the tiniest bit of root and spreads rapidly.

It grows between the roots of other plants making it hard to remove from between them. All in all, this is not a plant I would recommend in your garden, or the main bit of garden if you have a larger plot. If you love ground elder to bits, by all means grow it of course.

How I am tackling ground elder organically

TechniqueResultWinner
Cover with cardboard and 5cm compost mulchIt did stop the plant growing through while the cardboard lasted. Cardboard and mulch is a technique only meant on annual weeds however and as expected, it did not weaken the plant and as soon as the card decomposed by the following spring, the ground elder bounced back unscathed.Ground elder 1,
Jack 0
Mowing through lawnWhere ground elder is growing in our lawn, mowing it weakened and killed patches of it over time. On the edge of the planting area containing the ground elder it did keep growing back into the lawn, but only made it about 30cm and never further in than this with regular mowing. Covering an area with lawn until it’s gone completely should work, after a number of years. Ground elder 1
Jack 1
Eat it Lots of people have suggested eating ground elder into oblivion. I have tried eating its tender new shoots, it tastes quite nice as a salad crop. However anyone who’s tried dealing with ground elder will know, you’d have to be sat on the patch eating only ground elder for a number of years before your picking and munching truly made any kind of impact. Ground elder 2,
Jack 1
Digging outOne sure fire way of getting rid of a plant in a patch of soil is to dig it out with all of its roots. Unfortunately, like bindweed and couch grass, ground elder roots are brittle, snapping easily. The plant can also grow from tiny bits of roots you can’t see with your eyes. However, the good news is that with some careful handling you can grip a piece of root in one hand and then with a hand fork in the other, trace it back getting rid of as much root as possible. In areas where I’ve done this, the plant is noticeably fewer in number with lower vigour when it grows back. With repeated digging out across each year, over a number of years, eventually it should all be gone. The challenge will be under existing shrubs, the hedge and a wall it grows under where its roots can hide, but I’m hoping to at least dig it back to these areas! In progress
Loosen the soilBy digging out the ground elder I’m actually creating loose soil that makes it easier for the plant to grow in. Which sounds counterintuitive except loose soil also makes it easier to remove its brittle roots in future digging out sessions. In addition I have been recommended to cover areas with a thick layer of compost to encourage the plant to grow higher in this loose material to again make it easier to dig out. So I’m going to do both.In progress
Tagetes minutaMexican marigold, Tagetes minuta, is said to kill ground elder using chemicals produced by its roots. This is called allelopathy and while it might sound too good to be true, it’s a genuine thing, where some plants will release chemicals to suppress the growth of other plants. Whether Mexican marigold (an annual) has the strength to truly do this against such a vigorous plant as ground elder remains to be seen. I have to admit I am extremely sceptical that this will work, and yet I am hopeful enough to try it! I have some seeds in the propagator already to plant out later in spring and I’ll sprinkle the remaining seeds in the area. In progress
Weed suppressant mattingI’m going to cover some areas with weed suppressant matting to starve the plant of light. This will be like the cardboard but the matting won’t decompose, allowing it to stay put for a number of years hopefully killing the plant eventually. I have to admit I’ve tried this with couch grass and nettles and even after two years, the plants were alive and well! However, their roots were directly on the surface of the soil under the matting making it much easier to dig them out later and eliminate them. In progress
Out compete itOne thing I know I can do quite easily is plant up the area with a number of plants that will outcompete and eventually kill the ground elder over the years with a slow decline in light, moisture and nutrients. Generally anything larger than the ground elder, that completely covers it. I’m not at this point because I want to see if the above methods can remove it to allow smaller plants back in. not trying yet

If you have ground elder in your garden and would like some moral support, or have some hot tips to deal with it, take part in my community discussion about it.

Update: 5 May 2022

Above you can see our main patch of ground elder which sits largely beneath a shrub Magnolia and then runs under the hedge behind and under a dry stone wall behind that. I’ve begun by digging a metre around the outside of the patch, so I’ve already removed about 7 – 8 metres of roots in my first sweep of digging. It’s growing back but in lower quantities I can continue to dig. The challenge is how to get at it beneath the Magnolia and the hedge. Stay tuned.

Read more about the benefits and beauty as well as how to control more weeds in my book, Wild about Weeds.

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