Growth Habit: Rosette-forming whilst young and over winter, becoming erect to around 1m during spring and summer.
Type of Plant: Herbaceous perennial, with large tuberous root system.
Flowers: Tall, erect stems carry hundreds of compact green to red / brown flowers throughout spring and early summer.
Fruit/Seed: Produce masses of 3-valved fruits, released in summer.
Dispersal: Most dock seed falls close to the parent. Soil movement may distribute seeds. Soil cultivation may damage the root and create root fragments, allowing new plants to form from each fragment.
Distribution: Widespread throughout Tasmania, particularly in higher rainfall areas.
Status: R. crispus and R. obtusifolius are declared as Secondary Weeds under the Noxious Weeds Act 1964. Landholders may be required to control these dock species by an Enforcement Notice or to comply with prescribed measures contained in a regulation prepared under the Act.
- Docks can be very competitive in pastures and irrigated production areas, such as orchards. They can form large infestations and drastically reduce grazing capacity. They tend to grow prolifically on dairy properties especially in areas watered by washings from the dairy.
- They proliferate in irrigated orchards and plantation crops such as hops and can become the dominant herbaceous plant present. Seedling docks may compete with establishing crop plants. R. pulcher is far more tolerant of dry conditions than R. crispus and R. obtusifolius. It is not uncommon in lawns and recreational areas where it is an important weed.
Identification & Lifecycle: Dock species tend to be generally similar in appearance and identification in the vegetative stages is difficult. A reliable identification depends on an examination of the fruit.
Docks usually germinate in the autumn, developing as rosette plants through the winter. A flowering stem emerges during spring and the seed matures through summer. The stems usually die back during autumn and the plant over-winters as rosettes. Docks are perennials. They develop a deep tap root and can readily regrow from the root crown or pieces of the root following hoeing or cultivation.
- As with most broad-leaf weeds in pasture or turf, vigorous well managed grass will contribute significantly towards the prevention of dock establishment. Proper attention must be paid to fertiliser programs to maintain pasture vigour. In pasture, over-or under-grazing, especially the latter, should be avoided. Block grazing is strongly recommended. As far as possible, stock should be kept out of wet pasture to avoid pugging and damage to the pasture which opens the area to weed invasion. Attention to drainage of areas which get waterlogged or lie wet for extended periods will reduce dock problems.
- Seedling and young rosette docks can be killed by cultivation. Hoeing or digging can be effective if the whole plant, including the root, can be removed. Old docks, especially those with well developed tap roots will often survive cultivation, especially in autumn or winter. Dock infestations are often the result of poor drainage and waterlogging. Proper attention to drainage will help to control an invasion or reinfestation of these weeds.
- A wide range of herbicides are registered for use on docks in a variety of situations. For specific details please contact the DPIWE.
N.B. Always check the herbicide label before use.