April 2, 2009 Against a green pasture, the yellow flowers are attractive, but only to those who don’t know how much the invasive alien costs. Haleakala and Ulupalakua ranches and other pasture owners have spent thousands of dollars trying to eradicate the pernicious plant that came to these shores from Australia. The state has admitted that seeds from the Senecio madagascariensis Poiret were mixed with carpet grass seeds added to mulch used on roadsides. Each plant can produce 30,000 seeds a year. The seeds get spread by the wind, hiking boots, vehicles and passing animals. In addition to crowding out pasture grass, fireweed is toxic to cattle and horses, causing slow growth, illness, liver malfunction and sometimes death. Eradicating fireweed is difficult. Grasslands can be cleared only to sprout again next year. Spraying involves expensive chemicals that must be applied at least three times. A Makawao resident wrote a letter published Tuesday, accusing animal feed and lack of effort for the fireweed at a horse center. He was wrong. The center has been battling fireweed for at least 10 years and, as mentioned above, feed is not the source. There is one way to get rid of fireweed, bring in some hungry sheep. The animals devour the plants with no ill effects. It’s a tactic that has been used for years on the Big Island and is being used on Maui. Last June, the state announced it was developing another biological control — a moth known as Secusio extensa. The moth’s larvae attacks the leaves, which lead to limited flower and seed production and the eventual death of the plant. Removing fireweed from Maui pasture land will be a long battle and it requires cooperation. A single small patch of land where fireweed is allowed to grow can infect hundreds of acres. Owners of Upcountry land even as small as a backyard should be watchful and willing to root out the fireweed as soon as it shows itself. If it has lacy leaves and yellow daisylike flowers, it has to go. * Editorials reflect the opinion of the publisher.