Weed of the Week: Mayweed Anthemis cotula
Weed of the Week: Mayweed Anthemis cotula
By Laurence Gale
What is a weed? By definition a weed is a plant that is growing in the wrong place. Weeds take valuable space, water, sunlight and nutrients that may otherwise be accessible to important crops, in our case turf grasses. Weeds not only compete for these resources they can disfigure and cause problems to playing surfaces.
Weeds are very good competitors and take advantage of any opportunities to colonise turf situations, particularly when the sward is under stress and weak, leaving bare soil areas for weeds to populate. Weeds have many mechanisms and characteristics that enable them to do this, having thick waxy cuticle leaves that can be resistant to some chemicals, fast reproduction methods, the ability to reseed in 6 week cycles and deep tap roots enabling the weed to survive in compacted dry ground conditions.
Weeds have one of three life cycles: annual; biennial or perennial.
- Annual weeds: Live for a single season. These weeds germinate from seed in the spring or summer, flower and then die.
- Biennial weeds: Live for two seasons. During the first growing season, these weeds remain in a vegetative stage and, in the following year, produce flowers, set seed and die.
- Perennial weeds: Live for multiple seasons and flower more than once. Perennial structures (rhizomes, stolons, crowns, entire plants or roots) survive from year to year.
Some weeds may be harmful to the environment or noxious to your regional ecology. For example Japanese Knotweed (Fallopia Japonica) is fast becoming a major weed problem on road side verges and urban landscape areas, a very difficult weed to eradicate. It is very important to recognise weeds and seek effective controls methods to eradicate them from our facilities.
Weeds can also be used as an indicator of soil conditions. For example, knotweed and plantains both indicate soil compaction because they can maintain adequate root respiration at lower oxygen diffusion levels than other plants. Different weeds tolerate different soil conditions, some are alkaline loving and others acid loving. Getting to understand and recognise the physiology of these plants will help you become better turfgrass managers.
This week's weed is: Mayweed Anthemis cotula
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Scientific name
Family Life cycle |
Anthemis cotula
Asteraceae Annual |
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| Form / Appearance | Mayweed's flower resembles that of a daisy, but the foliage differs sharply, and actually resembles that of the Chamomile plant. Mayweed foliage is quite noxious and can cause skin irritations. The leaves are finely dissected, fern-like, with an unpleasant odour and acrid taste. Height: 30-60 cm. |
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| Roots | Taproot and fibrous root system. | |
| Flowers |
Flowers occur on solitary heads at the ends of branches. Flowers are approximately 8-12mm in diameter and are white ray flowers with yellow centres and usually flower from June-October. |
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| Leaves |
Leaves are alternate, finely dissected and formed on erect branching stems. Leaves are approximately 18-60mm inches long and 25mm wide. Leaves emit an unpleasant odour when crushed.
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| Reproductive method | By seed. | |
| Habitat |
Waste places and roadsides. |
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| Miscellaneous info |
This plant is also known as Stinking Chamomile and Dog-fennel and is a common weed found in most countries.
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| Cultural Control | Hand weeding or flaying off with a hoe or spade. | |
| Chemical Control |
Apply Non-selective herbicides when plant growth is active. There are a number of products available for controlling broad leaf weeds.
These chemicals are best used when the weeds are actively growing, usually between April-October.
These herbicides are usually applied as a liquid using watering cans, knapsack sprayers and vehicle mounted sprayers. Ensure you follow manufacturer's directions, health & safety and product data sheets, and comply with COSHH regulations, when using these chemicals. Herbicides are an effective tool where high quality turf is desired. However, they must be applied with care and accuracy and in the context of a good overall turf management program. Before using any herbicide, carefully review the label for conditions of use including rates, methods of application, and precautions. Never use an herbicide in any manner contrary to its label and be sure that the herbicide will not injure the turfgrass species |