Puncturevine (Tribulus terrestris) is a low-growing annual weed whose fruit breaks into hard, viciously spined burrs -- goatheads. The burr is not an incidental annoyance: it is the plant's seed-dispersal system, hitching rides on feet, paws, tires, and machinery.

A single plant can spread into a flat mat several feet across and produce hundreds to thousands of seeds in one season. The real enemy is therefore the seed bank, not just the plant you can currently see.

How to remove/control it

• Remember the lifecycle. Puncturevine is a warm-season annual. It germinates, spreads flat, flowers, makes burrs, and dies when freezing weather arrives.
• Get it before seed production. UC IPM says plants can begin flowering within about 3 weeks of germination, so small plants are worth removing early.
• Pull or hoe seedlings. Hand pulling and shallow hoeing/tilling can work well on seedlings and small plants; cut older plants at the taproot before or around flowering.
• Do not rely on mowing. Puncturevine grows too close to the ground for mowing to control it reliably.
• Collect dropped burrs. Sweep or rake them up; UC IPM even recommends pressing old carpet against the ground to pick up burrs.
• Repeat for years. Seeds can remain viable in soil for up to about 5 years, so control means preventing each new generation from replenishing the seed bank.
• Mulch can help. Around 3 inches of light-blocking organic mulch can suppress seedlings in beds and ornamental plantings where mulch makes sense.
• Avoid deep tilling. Deep tilling can bury viable seed and preserve future germination problems.

Recognition

Look for a prostrate mat radiating from a central taproot, paired leaflets, small yellow flowers, and -- most unmistakably -- the woody multi-spined fruit.