The Enemy: Puncturevine (Tribulus terrestris)
Strategy: This is an annual weed that grows flat on the ground and can form dense mats up to 15 feet across. This invader from Europe produces yellow flowers every four days. From this flower, eight pointed triangular seeds are formed that give this seed head the nick-name of goathead. It starts growing in June and remains viable until the first frost if not controlled.
Attack: This plant does not like competition, so we always find it in sandy, dry and gravely sites. We find it in along bike paths, railroad tracks, baseball fields and on the borders of farm fields. It has probably single-handedly supported many bike tire and car tire repair shops, as it will puncture bicycle and car tires.
Defense: Prevention is the best way to control it. Competitive plants (such as desirable grasses) are the best way to reduce its impact. Digging up these plants is effective, but keep in mind you must get to the root of the plant as it will grow back if you just scrape them off the surface. Just roll it in front of you with your shovel, and when you find the root, dig down to the taproot a couple inches, pick the plant up by this root and place it into your container for disposal. Residual herbicides (Krovar I DF, Piper, Esplanade, etc) applied in late fall or early winter can prevent the weed from growing. In sensitive sites such as alleyways Telar XP at 1.5 ounce is effective. Also effective is 2,4-D, but you must treat often.