A pain in the agapanthus

angelawadsworth
Jul 3
2 min read

July's pest plant of the month!

A dense stand of wild ginger in flower — Agapanthus spreading and surrounding a native tree

Why is agapanthus harmful, and does it matter if people continue to grow it? Agapanthus is difficult to remove, spreads quickly, and hinders the growth of our valuable native plants, which negatively impacts our native birds and other wildlife.

Do you have kids or pets playing in your garden near agapanthus? The sticky sap from this plant can irritate skin and eyes, and some parts of it are toxic if ingested. To protect yourself, your family, and local wildlife, it's best to remove agapanthus if you are able. The good news is that Aotearoa boasts beautiful native plants that can replace agapanthus. These native options are not only long-lasting but also beneficial for local wildlife. Read on to learn more!

What does it look like?

Umbrella-like clusters of large, tubular white/blue/purple flowers - typically flowers December-February
Thin, papery black seeds
Long, dark green, leathery leaves curve away and down from the centre of the plant
Form dense masses or clusters of foliage and roots (rhizomes)
Long, thick, white rhizomes (roots) forming dense mats

Agapanthus growing on a roadside verge preventing native plants from establishing

Why is it weedy?

Dense clusters prevent any other species from growing
Loss of biodiversity where it grows, outcompetes native species and other garden plants
Will eventually take over and become the dominant species wherever it grows
More difficult to remove once established
Spreads through root/rhizome fragments, especially from dumped garden waste
Also spreads through wind-dispersed seeds
Not a food source for native species, and some parts are toxic.

An area of Agapanthus being controlled, revealing the dense roots and rhizomes — An area of agapanthus being controlled, revealing the dense roots and rhizomes

What can I do to get rid of it?

Dig up roots and rhizomes
Dispose of roots/rhizomes in a container of water with a lid or in a heavy-duty weed bag to rot down over several months, dry them out, or burn them
Cut down stems and foliage and leave on site to mulch down.
The cut stems can be pasted with Metgel (Metsulfuron gel if they are NOT close to valued plants or water, otherwise use Bamboo Buster (double strength glyphosate)*, which may be less effective
Return and retreat any regrowth after 1 or 2 months, or dig up remaining clusters.
Talk to your friends, family and neighbours about how bad agapanthus is and encourage them to take action too

See all our pest plant disposal information on our website.

*Always read the label before using any herbicides. Other herbicide treatments are possible.

If you have a significant area of agapanthus threatening an area of bush or a reserve, get in touch and we’ll see how we can help.