Montbretia

montbretia-Crocosmia-x-crocosmiiflora.jpg

Crocosmia x crocosmiiflora

Origin: South Africa
Size:  60cm to 90cm H
Flowers: December to April
Fruits: December to April
Best time to remove: October to April

What it does

Montbretia invades gardens, bushland, roadside areas and stream sides. It tolerates all conditions and can take over and displace indigenous grasses, groundcovers and over-storey regeneration.

Montbretia is a perennial herb which dies back annually. It is grass-like in appearance and often mistaken for Watsonia. Montbretia features strap-like flat leaves around 30 – 80 cm long and 1 - 2 cm wide. It was a popular garden plant due to its bright orange trumpet-shaped flowers, which form in two rows along each stem.

New growth is produced in early spring and small bulbils can be produced from the flower base. The fruit is a 3-lobed brown capsule that produces few seeds.

How it spreads

  • natural regeneration is usually next to the parent plant from corms that spread rapidly underground to produce new plants.
  • as a result of ground disturbance, dumping of garden waste and by attaching to machinery.
  • it is often sold in nurseries, fetes or market stalls.

Removal

The most effective time to remove Montbretia is just before full flowering occurs around spring and summer and/or digging out bulbs when the soil is wet.

Remove by hand

Hand removal is only practical for small clumps of the weed. Use a garden fork to dig all corms and underground stems to ensure complete removal. Cut stems first if the plant is in seed.

Spray with herbicide

Use a registered product and ensure you check the label and follow instructions.  Ring the Department of Energy, Environment and Climate Action on 136 186 for full details.

Montbretia leaves can also be swiped with a glyphosate-based product.  The most effective time is just before full flowering which occurs in summer to autumn. 

Dig out

Dig out patches of Montbretia weed carefully when soil in moist as corms break off easily; corms often form linked chains.

Indigenous alternatives to plant

Many clumping alternatives indigenous to the Yarra Ranges region are available and would make great substitutes for Montbretia. Some alternatives include:

Tasman Flax-lily, Dianella tasmanica

Pale Flax-lily, Dianella longifolia

How to dispose of weeds

By disposing of environmental weeds correctly you can prevent re-infestation on your property and elsewhere.

  • Landfill (Weed Wipeout Tip vouchers available for some species).
  • Green waste bins ensure that weeds are not able to spread.
  • Woody weed stems can be bundled for green collection twice per annum.
  • Composting (excluding seed heads or species with vegetative reproduction, e.g. Wandering Trad).
  • Burning in accordance with Council and the Country Fire Authority (CFA) prescribed burning periods and regulations.
  • Recovery and transfer stations available for weed tipping are Healesville, Wesburn, Coldstream, Lysterfield and Montrose.

Using chemicals

Non-chemical treatment is often the most effective and safe option especially on smaller scale infestations.

Where chemical use is undertaken:

  • Always follow the manufacturer’s guidelines when using chemicals.
  • Wear protective clothing and eyewear.
  • When purchasing your herbicide, always ask for a Materials Safety Data Sheet (MSDS) or refer to the manufacturer’s website for specific safety guidelines and information.
  • Some herbicides will kill other plants and not just the target species.
  • When used near waterways herbicides can be very poisonous to aquatic life.
  • Use chemicals sparingly and be sure that you are using the right chemical and application technique.
  • Ensure the weather conditions are suitable (e.g. minimal wind and no rain expected).
  • Apply herbicides at the correct time during the plant’s growth cycle so you get the best results.