Marigolds
It’s the time of year again when stinknet (Oncosiphon piluliferum, also called globe chamomile) is growing fast here in Phoenix from the winter rains. This non-native, invasive weed is spreading rapidly across Maricopa County and is a fire hazard, in addition to being damaging to our native ecology by outcompeting our native plants. There are no natural predators in the Sonoran Desert for this South African plant, and none of our pollinators use it either.
Stinknet info from the U of A Cooperative Extension: What to Do: Eliminate it as soon as possible after it emerges; do not let it flower. Pull by hand or use a hula hoe or weed whacker (plants cut with string trimmer may grow back). Brush off clothing and shoes at the trailhead after hiking in stinknet areas. Clean tarps, tents, and other gear after camping near the weed. Do not allow pets to run through patches of dry stinknet. Clean them off if they do. Remove dead stinknet carefully—it will shed thousands of seeds, which can live in soil up to five years. Be sure to look annually for young plants, and remove them before they can go to seed.