Pineapple weed, Matricaria matricarioides
, relishes the challenge of rooting into a well-trodden path or other seemingly unhospitable soils. When walked on the plant's leaves release a pleasant pineapple-like scent, but a single plant will flower and produce thousands of plants in its short lifetime, quickly spreading through the garden.
Pineapple weed will spread and root in any open ground - even in compacted earth and paths - competing with plants for nutrients and space.
Hand weed or hoe out seedlings as they appear, or smother them with a good layer of compost or mulch. Try to remove plants before they flower and seed to slow its spread.
Use a total weedkiller, such as glyphosate. Avoid spraying on a windy day and near other desirable plants.