Ground elder (Aegopodium podagraria) is a fast-growing, invasive, perennial weed that can spread quickly to form a carpet of foliage that will crowd out less-vigorous plants in beds and borders.
What is ground elder?
Ground elder is an herbaceous, invasive, perennial weed. It spreads via rhizomes (underground stems), which can regenerate from a just a tiny fragment left in the ground.
Early in the year, shoots with dark green leaves burst from the soil. These are followed in late spring and early summer by tall stalks that support several flat heads of white flowers. There is also a form with variegated leaves. The flowers bear a resemblance to those of the elder tree (which is completely unrelated), and this gives the weed its common name.
Ground elder rhizome and young shoot.
Ground elder in flower.
Spreading by rhizomes, ground elder can easily creep in from a neighbouring garden or nearby wasteland. It can also be unknowingly introduced with new plants if pieces of its fleshy, white rhizome are hidden within the compost of the rootball or are tucked away among the roots of the plant.
As its rhizomes are close to the surface of the soil, it is possible to reduce infestations of ground elder by removing it carefully with a garden fork. However, eradicating it completely needs vigilance as the smallest portion of root left in the soil will result in a new plant growing.
Tackling large infestations of ground elder in a well-planted bed can be difficult. To get rid of it completely requires time and patience. Try the following non-chemical approaches:
- Lift cultivated plants and carefully remove and destroy any pieces of ground elder rhizome from around their roots
- After you are sure it has all been removed, replant your garden plants in clean soil or pots
- The ground elder can now be evicted by digging, or by covering the ground with black polythene to starve the weed of light. It may take several seasons until the ground elder is completely destroyed
In new lawns, ground elder will usually be starved by repeated mowing, and should not persist for long.
- Established ground elder can be controlled by spraying with a tough weedkiller containing glyphosate (e.g. Scotts Roundup Ultra 3000, Scotts Tumbleweed, Bayer Tough Rootkill, Bayer Super Strength Glyphosate or Doff Knockdown Maxi Strength Weedkiller)
- Protect cultivated plants with sheet polythene or by pegging them out of the way, and take care to avoid spray drift. The gel formulation (Scotts Roundup Gel) may be easier to apply in such a situation
- Apply the spray in mid-summer when there is lots of leafy growth, then reapply if necessary later in summer
- Spraying in the evening will be far more effective than spraying during the day as more of the chemical will be absorbed by the foliage
- Bayer Long Lasting Ground Clear containing glyphosate/flufenacet/metosulam comes in a soluble sachet. It can be applied once a season to natural surfaces where no plants are to be grown, and can also be applied under and around established woody trees and shrubs, including roses. This product kills off existing small green growth and may prevent or check developing growth of ground elder at the base of hedges or other woody plants. Check manufacturer’s recommendations before use to avoid damaging sensitive plants
Weedkillers for gardeners (Adobe Acrobat pdf document outlining weedkillers available to gardeners; see sections 4 and 5)
Chemicals: using spot and broad-scale weedkillers
Chemicals: using a sprayer
Chemicals: using safely and effectively
The Chemicals Regulation Directorate, part of the Health and Safety Executive, would like to know more about how garden chemicals are used in order to develop guidance on safe use, storage and disposal of them. If you can spare 5-8 minutes, join in their online survey which is being run until 14th June 2013.