Invasive climbers & grasses (Mikania, Chromolaena, Imperata, Borreria)
Four aggressive weeds of young coconut and tea plantations that need ongoing manual control until the canopy closes over.
- Type
- Mixed weeds (climbing vine, shrub, grass, ground cover)
- Life cycle
- Perennial; some spread very fast and are hard to eradicate once established
- Spreads by
- Stem fragments, wind-borne seed, and deep underground stems
- Main harm
- Smother or choke young plants; compete strongly before the canopy closes
Overview
Young or newly replanted coconut and tea plantations face four aggressive weeds on their open ground, margins and slopes. Mikania (mile-a-minute weed) is a fast-growing climbing vine with light green, arrow-shaped leaves that grows over and completely covers young plants if left unchecked. Chromolaena (Siam weed) is a dense, woody shrub that forms thick, tangled patches and can block movement between rows. Imperata (cogon grass) is a tall, tough grass with sharp-edged leaves and deep underground stems (rhizomes), often found on slopes and open margins, and dries out to become a fire risk in the dry season. Borreria (buttonweed) is a smaller, low broadleaf weed with tiny white flowers clustered like small buttons, mainly a ground-cover competitor rather than a smotherer.
All four establish fastest on open, uncovered ground, so they need ongoing manual control rather than the routine basin weeding used for smaller weeds. Once the canopy closes — tea bushes meet across the row, or coconut palms mature and shade the ground — most of these weeds are naturally shaded out, so the real risk window is the young plantation stage.
How to identify it
- Mikania (mile-a-minute weed): a fast-growing climbing vine with light green, arrow-shaped leaves that grows over and completely covers young plants if left unchecked.
- Chromolaena (Siam weed): a dense, woody shrub that forms thick, tangled patches and can block access between rows.
- Imperata (cogon grass): a tall, tough grass with sharp-edged leaves and deep underground stems (rhizomes), often found on slopes and open margins; dries out to become a fire risk in the dry season.
- Borreria (buttonweed): a smaller, low broadleaf weed with tiny white flowers clustered like small buttons, mainly a ground-cover competitor rather than a smotherer.
Why it is a problem
- Mikania is a serious threat to young palms and tea bushes, since it can grow over and completely cover a small plant within weeks in the wet season.
- Chromolaena forms dense thickets that block movement and compete strongly with young plants for light and nutrients.
- Cogon grass has deep underground stems that make it very hard to dig out fully, and dry stands are a fire hazard.
- All four establish fastest on open, uncovered ground — young or newly replanted plantations, and the edges/slopes of established ones, are most at risk.
Cultural & preventive control
- Slash or cut climbers and shrubs regularly, especially before they smother a young plant or set seed.
- Where feasible, dig out cogon grass rhizomes (underground stems); persistent repeated slashing also exhausts the plant over time if digging is not practical.
- Grow a cover crop or intercrop (such as legumes or a managed cover in the open inter-row space) to occupy bare ground before these weeds do.
- Once the canopy closes, most of these weeds are naturally shaded out, so the real risk window is the young plantation stage.
Herbicide control
- Blanket herbicide spraying is usually impractical and costly over a whole plantation, so spot application on regrowth or cut stumps of climbers and shrubs is the common approach.
- Keep herbicide off young palms, tea bushes and any intercrops.
- A repeat spot-treatment is often needed for regrowth, since these are aggressive, persistent weeds.
- Confirm the current recommended herbicide and safe method for spot use in your crop with your local KVK.
Integrated management
- Combine regular manual slashing of climbers and shrubs, rhizome removal or repeated slashing for cogon grass, spot herbicide on regrowth, and a cover crop on open ground.
- Prioritise young and newly replanted areas, since that is where these weeds do the most damage before the canopy closes.
- Watch field margins and slopes closely, since that is usually where these aggressive weeds first establish before spreading inward.
Crops most at risk
Where this problem is called out in our crop guides — open a crop for the full package of practices.
Frequently asked questions
What are these different weeds taking over parts of my coconut/tea plantation?
A fast-growing vine with light green, arrow-shaped leaves that grows over and covers young plants is Mikania (mile-a-minute weed). A dense, woody, tangled shrub is Chromolaena (Siam weed). A tall, tough grass with sharp leaves and deep underground stems is Imperata (cogon grass). A smaller ground weed with tiny white button-like flower clusters is Borreria. All four are aggressive weeds that establish fastest on open ground in young plantations and need regular manual control rather than routine basin weeding alone.
Why do these weeds mostly show up in young plantations and not older ones?
All four need open, sunlit ground to establish and spread quickly. In a mature plantation, tea bushes meeting across the row or coconut palms with a full canopy shade the ground enough to naturally suppress most of this growth. Young or newly replanted areas, where the ground is still open, are at the highest risk — so the extra weeding effort is most worth investing there, tapering off as the canopy closes.
Is it worth digging out cogon grass, or is cutting enough?
Digging out the underground stems (rhizomes) gives the most complete control where it is practical, since cogon grass regrows readily from any rhizome left behind. Where digging the whole area is not practical, persistent, repeated slashing before the grass can build up its rhizome reserves will gradually weaken and exhaust the stand over a season or two, though it takes longer than removing the rhizomes directly.
Symptoms and control measures follow ICAR, KVK and state agricultural-university package-of-practices; any named chemical is a registered use. Always read the product label and confirm the dose for your crop and zone. editorial policy.