by St. Gabriel
Milky Spore begins working as soon as it is applied as long as grubs are feeding. Once grubs are infected they will multiply the spore by several billion times and spread it further. In warm climates good control can occur in one to three years, and in colder areas like New England, three to five years. Once established in a lawn, Milky Spore has been known to last 15 to 20 years.