I've had really good results with iron phosphate in recent years, I plan to stick to that. I use very scant amounts but treat each bed at least twice, sometimes 3 times, beginning in very early spring when slugs become active, long before I start planting. Slugs used to be a huge issue in spring, but not since I use the iron phosphate.
Slugs apparently become active when soil temp reaches around 40°. I measure soil temp, when it hits 40, I start applying.
They've never been a problem in summer. It's generally too dry for them here in our hot, dry summers.
Karen
