Arum lily

Scientific name: Zantedeschia aethiopica
Other names: Death lily

Shrub

About Arum lily

What does Arum Lily look like?

Arum Lily is a dark green shrub that grows up to 1.5 m with new tubers arising from shoots on the rootstock. It is evergreen with large, leathery, arrow-shaped leaves that produces large white flowers with yellow spikes and yellow-green berries (10 mm). It looks similar to the Italian arum (Arum italicum), which is also a weed, but it has distinctive white veins on the tops of the the leaves. The Arum Lily persists under regenerating canopy, forming dense patches that exclude all other plantlife. You can find them in swamps, open damp areas with low cover, and regenerating ex-pasture, especially downstream or adjacent to infested areas. Its adaptable to the wind, wet, salt, hot, cold and most soil times. It requires moderate shade and is drought-resistent once it's established. It will smother the ground preventing other native plant seedlings to grow. It's poisonous to animals, and can eventually dominate grazing sites.

How does it spread?

The parent plant drops seeds that are occasional spread by birds and water. Once seeds are dropped, clumps expand slowly by growing new shoots. Tubers and seeds are often spread by dumped vegetation and soil movement, which is why it's important to be careful when getting rid of garden waste or integrating plants from the store or other gardens.

How do I get rid of it?

Mowing will not get rid of the Arum Lily. Digging usually leaves root fragments and dropped tuber pieces that can resprout. Make sure to follow-up with the site every 3 months to prevent small infestations that can regenerate into a dense forest if left unattended. 

Start clearance at the top of the catchment by slashing the tops off, leaving the rest of the plant on site to rot down. You should dig out the tubers, dry and burn them, or bury them deep in the ground. After you've slashed the tops off, cut them down and paint the stumps with 1 g metsulfuron-methyl 600 g/kg mixed with 100 mL glyphosate plus 10 mL penetrant/L water. Leave the rest of the stems and leaves on site to rot down. You can also use weed wipe which is 1 g metsufuron-methyl 600 g/kg mixed with 150 mL glyphosate plus 10 mL penetrant/L water. Or you can spray it with 3g metsulfuron-methyl 600g/kg mixed with 150 mL glyphsate plus 10mL penetrant/ 10 mL water.

What can I plant instead?

Try growing NZ Daphne (Pimelea prostrata) or Mingimingi (Coprosma propinqua) instead. What other native plant would you recommend?