Dandelion (Taraxacum officinale)
Dandelion is one of the most recognisable weeds found in New Zealand lawns. Its bright yellow flowers might look harmless, but once it takes hold, its deep taproot and tough rosette growth make it difficult to remove.
Although dandelion doesn’t cause major problems in pastures, it’s a common nuisance in home lawns, gardens, and roadside verges. It thrives in areas where grass is thin or the soil is compacted or low in fertility. Its long taproot allows it to survive dry periods and quickly regrow even after being mown or partially pulled out.
Dandelions can flower almost year-round in many parts of the country. Once the flowers mature, they form fluffy seed heads that spread easily by wind, helping the weed establish across wide areas of turf.
Identification
Dandelion forms a flat rosette of long, irregularly toothed leaves that radiate from a central crown. Each leaf is hairless and tapers toward the base, with lobes that point back toward the centre of the plant.
The flower stalks are hollow and fleshy, each carrying a single bright yellow flower head about 2–3 cm across. After flowering, the heads turn into familiar white seed puffs that release hundreds of wind-borne seeds.
Dandelion is often confused with similar yellow-flowered weeds such as catsear, hawkbit, and hawksbeard. The easiest ways to tell them apart are:
- Dandelion leaves are smooth (not hairy).
- Its flower stems are unbranched and hollow.
- Catsear and hawksbeard have branched flower stems.
- Hawkbit stems are wiry and solid, not hollow.
Why It’s a Problem in Lawns
Dandelion is an aggressive competitor in lawns, especially in bare or compacted areas. Its wide rosette smothers surrounding grass, while its deep root system allows it to recover from mowing, pulling, and even light herbicide applications.
Once mature, dandelion can drop seed throughout the lawn and surrounding areas. Because the seeds germinate easily on exposed soil, they often appear after soil disturbance, aeration, or during periods of thin grass growth.
Their bright flowers and broad leaves disrupt the even look of a healthy lawn, and they often return unless the full root is removed or treated properly.
Control in Home Lawns
Effective dandelion control requires removing or killing the entire taproot and preventing new seedlings from establishing.
Best control methods:
- Physical removal: Hand-dig individual plants using a narrow weeding tool or knife to remove as much of the taproot as possible. Any fragment left in the ground can regrow, so complete extraction is key.
- Chemical control: Use selective broadleaf herbicides containing MCPA, mecoprop, and dicamba, which are widely available at garden centres. For tougher infestations, products containing triclopyr/picloram (NZLA Gold) or clopyralid (NZLA BWC) offer strong control.
- Timing: Apply herbicides in autumn or spring when plants are actively growing and before they set seed. Avoid mowing for several days before and after treatment.
- Non-selective control: For severe infestations or lawn renovation, glyphosate will kill dandelions effectively, but it also kills grass, so reseeding will be required.
Prevention Tips
- Fertilise regularly to keep the lawn dense and healthy.
- Aerate compacted soil annually to discourage tap-rooted weeds.
- Mow at the correct height to shade soil and reduce weed seed germination.
- Reseed bare areas quickly after weeding or spraying.