Wooly nightshade
Solanaceae - Solanum mauritianum
BioSecurity

What does it look like?

Woolly nightshade is a shrub or small tree that can rapidly grow to 10m tall. It has large, grey-green leaves that are up to 25cm long and are covered in felt-like hairs.  The leaves have an unpleasant, pungent (kerosene-like) smell when crushed. It produces purple flowers with yellow centres and bunches of yellow berries when ripened.

Woolly nightshade is adapted to a wide range of habitats. It can invade forest margins, disturbed forest, light gaps within forest, shrublands, riparian margins, estuarine margins, consolidated sand dunes, wetlands and urban areas. It rarely invades intact habitats. Can also be problemtic along roadsides and exotic forest margins.

Why is it a problem?

Woolly nightshade grows very rapidly and can crowd-out or shade-out native plants to form dense stands. It also effectively poisons the soil to inhibit or prevent the establishment of other less hardy species, including native plant seedlings. This has the effect of preventing the regenration/establishment of native forest. 

This plant is moderately shade-tolerant, tolerant to frost and requires medium to high soil fertility. Dense stands can ivade pasture on poor soils, especially in hill country areas and impede livestock movement. All parts of the plant are thought to be toxic to livestock.

Woolly nightshade can flower and fruit at any time of the year, producing large numbers of viable seeds.  Even very young plants can produce seed, for example, seedlings established in summer can bear flowers by the autumn. It also spreads vegetatively when mechanically damaged by cutting or uprooting and pieces of root remaining in the soil will regrow.

Control Methods

Small plants: Pull out and leave on site to rot. This is easiest in winter.

Options for larger plants:

  1. Cut and squirt (all year round): make cuts at regular intervals around the trunk, apply undiluted Tordon Brushkiller (1.5ml per cut).
  2. Cut and paint stumps (all year round): Tordon Brushkiller or triclopyr 600 EC (100ml/L) or Vigilant gel.
  3. Frilling (all year round): Tordon Brushkiller (100ml /L) or triclopyr 600 g/L (100ml/L) or Yates Woody Weedkiller (200ml/L).
  4. Injection method: use either 10 mm wide holes drilled at 45 degree angle down into trunk 50 mm deep spaced at 50 mm around trunk, or a series of 80 mm wide blazes cut to a depth of 15-20 mm, spaced at 20-40 mm. Fill each with Vigilant gel.
  5. Spray: Tordon Brushkiller (25ml/10L) or triclopyr 600 EC (60ml/10L) or triclopyr 300 EC (12ml/L).

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