Watsonia

Watsonia meriana var. bulbillifera

Family: Iridaceae

Type of weed:

Flowering Months: , , , ,

Description

A long-lived, upright, herbaceous plant emerging each year from underground corms and growing up to 2m tall. Upright flowering stems are often reddish.

It has very large strap-like leaves. Most of the leaves arise from the base of the plant.

Tubular flowers are widely spaced along the flower spike. Flowers orange, red or salmon pink with six fused ‘petals’, in spring and early summer.

Fruit and seeds are generally not produced in Australia. Instead, clusters of small reproductive structures (bulbils) are produced at the upper stem joints.

Don’t confuse with…

Watsonia can be confused with native Dianella spp. and the weed Montbretia. (Under the ground Montbretia has long strings of corms which break away when the parent plant is disturbed and begin to shoot.)

Dispersal

It spreads vigorously by underground ‘bulbs’ (corms) and smaller ‘bulbs’ (bulbils). Corms are washed downstream. It is dispersed by the movement of soil containing corms and in dumped garden waste.

Impact on bushland

Watsonia displaces native understorey plants. Concentrations of the plant create a fire hazard in summer.

Distribution

, . Particularly Upper Mountains.

Alternative planting

Native plants

  • Native Water Ferns (Blechnum spp.)
  • Dianella spp.
  • Native Saw Sedges (Gahnia spp.)

Council provides a tool, on its Mountain Landscapes website, to help you choose native alternative plantings. Choose your village, soil, vegetation community and the purpose of your planting, and the tool will give you suggestions.

There are native nurseries in several Blue Mountains villages, including Glenbrook, Lawson and Katoomba. Please also ask at your favourite local nursery.

Control

  • Dig out corms and remove flowering stems which carry bulbils (spring to summer).
  • Bag and remove all corms and bulbils, or bag and remove all stems with bulbils.
  • Wipe leaves with herbicide between flowering & fruiting (summer). In open areas away from tree roots and swamp vegetation, spot spray with herbicide.

For more info

For key points on these techniques:
  • Gloved hand using adapted tongs with sponge to wipe herbicide onto leaves

    Montbretia wiping