Broad-leaved Plantain (Plantago major)
Broad-leaved plantain is one of the most common flat weeds found in New Zealand lawns. It’s a low-growing perennial with broad, spoon-shaped leaves that form a dense rosette close to the ground. While it’s not particularly aggressive, it spoils the look of fine lawns and thrives in compacted or poorly drained soil—especially in areas where grass has thinned out.
This weed is extremely hardy. It tolerates mowing, treading, and even waterlogging, making it a frequent visitor in drive-on lawns, pathways, and around the edges of driveways. In short, if your lawn is compacted or neglected, broad-leaved plantain will move in and stay.
Identification
Broad-leaved plantain forms flat, oval leaves that spread outward in a rosette. The leaves have smooth edges and very prominent parallel veins that run the full length of the leaf—a key feature that separates it from most other flat weeds like dandelion.
In summer, it produces tall, narrow flower spikes that rise above the foliage and carry small, brownish seed heads. Unlike narrow-leaved plantain, the leaves of this species are wider and shorter, and the seed spikes extend further down the stem rather than clustering near the tip.
The plant has a fibrous root system with a central crown just below the soil surface, rather than a single deep taproot. This makes it resilient and able to regrow if not completely removed.
Why It’s a Problem in Lawns
Although broad-leaved plantain doesn’t spread rapidly, it thrives in the exact conditions that weaken grass—compaction, low fertility, and poor drainage. It creates unsightly patches that resist mowing and disrupt the even texture of a well-kept lawn. Because it sits so flat, it often avoids mower blades entirely, staying green while surrounding grass struggles.
Control in Home Lawns
Broad-leaved plantain is one of the easier broadleaf weeds to control chemically, but a single herbicide spray won’t solve the underlying soil issue that allows it to thrive.
Best control methods:
- Physical removal: For small infestations, dig out the entire rosette with a narrow spade or weed knife, ensuring the crown is removed.
- Chemical control: Use a selective broadleaf herbicide containing actives such as MCPA, mecoprop, or 2,4-D. These are highly effective against plantain when the weed is actively growing.
- Avoid dicamba alone: It gives poor results on established plantain. Clopyralid (e.g., NZLA BWC) can also work but requires higher rates.
- Cultural improvement: Aerate compacted areas, apply balanced fertiliser, and overseed thin patches. Improving lawn health and drainage makes it harder for plantain to re-establish.
Prevention Tips
- Aerate heavy or compacted soils once or twice a year.
- Keep the lawn thick and well-fed to reduce bare areas.
- Reseed quickly after weed removal to prevent reinvasion.
- Avoid overwatering or allowing puddling, as plantain thrives in damp, compacted zones.