Mignonette vine

Mignonette vine, a garden escape, thrives in warm, moist climates and on fertile soils. It can rapidly climb over and smother desirable plants, killing them by blocking out light and toppling smaller trees with its thick, heavy blanket of growth. It can also grow over fences and hedges, blanketing them with its vines.

Although it doesn’t produce any seed in New Zealand, mignonette vine can readily grow from even small fragments of its aerial tubers or rhizomes (roots). It spreads mainly via these fragments in illegal or inappropriately dumped garden waste.  

Physical control

• Remove all underground and stem tubers and burn, or take the whole plant to a refuse transfer station. Home composting will not kill mignonette vine.
• Remove every scrap of vine from affected trees and shrubs. Any stems or tubers touching the ground will regrow, so be careful not to drop any when moving them. 

Photo credit: Forest & Kim Starr

Herbicide control

Stem scraping

• Use a sharp knife to carve away the outside of a stem, removing about a third of its diameter.
• Apply herbicide immediately.
• Gouge tubers carefully and apply herbicide.
• Do not remove the roots from the soil or the treated vine until the stems are quite dry (6-12 weeks, depending on weather).

Cut vine treatment

• Slash vines at ground level and immediately paint herbicide* on both stem sections. Use a squeeze bottle to apply herbicide to avoid splashes.
• Swab hanging ends of the vine and use a dye to keep track of stumps.
• Pull out and rake up all aerial tubers, then burn.

*Note: If picloram gel is used, best results are achieved during periods of active growth (November to April). Cut the stem 50-100mm above the ground before applying, instead of at ground level.

Spray application

Best results are achieved between January and April.

• Control large infestations by cutting back the top growth to 2m and spraying all leaf surfaces on remaining stems.
• Protect surrounding plants by cutting back any growth covering the vine before spraying.
• Dispose of cut growth at a refuse transfer station.
• Monitor closely and repeat spray as regrowth appears.

Safety when using herbicides

• Follow the instructions on the manufacturer’s label.
• Always wear protective clothing.
• Always minimise the risk to your other plants.
• Contact the supplier for further advice.

Summary of herbicides and application methods for control