(Arctotheca calendula)
What is capeweed?
Capeweed is a troublesome pasture, crop and garden weed in Tasmania.
How to identify capeweed
- Capeweed is an autumn-germinating annual plant, with seedlings appearing from late February through to late April. As plants mature they develop into a rosette, or whorl of leaves close to the ground.
- Capeweed rosettes are similar to storksbill, crowsfoot, bittercress, and mustards, but can be identified by the undersides of the leaves which are whitish and covered by a thick mat of short hairs.
- Flowering occurs in late spring and early summer; the masses of yellow, daisy-like flowers with dark, almost black centres are conspicuous from a considerable distance. Capeweed dies off in late summer.
- For help in identifying capeweed, search the
Dennis Morris Weeds and Endemic Flora database for capeweed illustrations. If you are still in doubt about the weed you are dealing with, contact Biosecurity Tasmania on 03 6165 3777 for help.
Image top: Capeweed, © K. Fenner.
Images above, L-R: Capeweed rosette, © M. Baker; Capeweed rosette and flowers,
©
K Fenner.
Capeweed in Tasmania
- Capeweed is not declared in Tasmania.
- Capeweed is distributed throughout Tasmania, particularly on light sandy soils.
- Capeweed competes with pasture grass and clover, and in the home garden with herbaceous and lawn plants. Capeweed is nutritious to stock and is valued by some graziers. However, capeweed does not provide continuous ground cover over summer and leaves the ground open to erosion during this period.
- Capeweed can accumulate toxic levels of nitrate on high fertility sites (such as stock camps and stock yards), while milk from dairy cattle may also become tainted when stock eat capeweed.
Detailed management and control guidelines for capeweed can be found in the Capeweed Control Guide. Refer also to
Herbicides for Capeweed Control.
See also:
Herbicides for Capeweed Control
Weed Links and Resources
Other useful links:
Pest Genie
APVMA
Capeweed Control Guide
Do
- Plan your control program, this will save time and money in the long-run;
- Consider the impact of your control methods on off-target species, especially if herbicides are used;
- Ensure machinery and equipment is washed down between sites or prior to contractors leaving site;
- Get in early - for new infestations, eradicate before the plants reach the flowering stage: once plants begin seeding, control becomes more difficult and expensive;
- Carefully time your use of herbicide for best results (see
Herbicides for capeweed control for more information);
- Coordinate your control program with neighbouring landholders where your weed problem crosses property boundaries;
- Revisit and regularly inspect the site and ensure follow-up is undertaken;
- Avoid bare soil patches in late summer and autumn as these can be colonised by capeweed;
- Maintain a healthy unbroken pasture - this is the best way to avoid capeweed infestations;
- Hand-pull small patches; use cultivation and sowing to pasture or crops to eradicate large infestations.
Don't
- Don't introduce capeweed to capeweed-free areas (e.g. by failing to wash down machinery and equipment between sites);
- Don't start your control program without first planning your approach;
- Don't allow capeweed to flower and set seed before treatment;
- Don't rely on one attempt at removal - follow-up is essential;
- Don't heavily graze capeweed-infested pasture in late summer and autumn as this can lead to bare patches of soil and re-colonisation by the weed;
- Don't rely just on herbicide control, establish vigorous pasture after removal to reduce re-infestation.
Avoiding the establishment of capeweed
- Capeweed is spread by seed. Seeds are spread by birds and animals, and as a contaminant in soils on vehicles and machinery.
- See the
Washdown Guidelines for Weed and Disease Control for detailed information on how to wash-down equipment and personnel to reduce the chance of spreading capeweed.
Physical removal
- Pulling or grubbing can remove capeweed where infestations are small.
- Use a fork as capeweed can be difficult to pull by hand. First loosen the soil around the plant then lift, taking care to remove as much of the root system as possible.
- Chipping is generally unsuitable as regrowth from the portion of root left in the ground is likely.
Cultivation
- Cultivation can be used to remove established infestations. Cultivate to expose the root systems with minimal breakage and leave the plants to dry out and die.
- Cultivation can be combined with cropping or pasture establishment to control large and well established infestations.
Grazing
- Grazing management should aim at maintaining a continuous and vigorous pasture.
- Heavy grazing during late winter or early spring can control capeweed.
- Heavy grazing during late summer or early autumn has the opposite effect, as the bare patches of soil left behind are readily colonised by capeweed seedlings.
- Under-grazing can also favour capeweed as pasture grasses and clover are grazed preferentially, leaving the capeweed to mature and produce seed.
Chemical control
- A number of herbicides are registered for use on capeweed. See
Herbicides for Capeweed Control for more information.
- Herbicide control is only a short term solution; unless a vigorous sward is established to compete with the capeweed, the weed is likely to re-establish.
- Application of 2,4-D (and possibly MCPA) can increase nitrate levels in some plants. Where capeweed growing on stock camps or other high fertility areas is treated with these herbicides, stock should be removed from the area until the plants are dead.
Herbicides for Capeweed Control