Metaldehyde is a lot more effective than iron phosphate. We use a metaldehyde bait twice a year here, once in the spring and again in the fall, then spot treat any bad spots in the summer, and we have very little slug damage.

You also need very little metaldehyde to do a good job - about 5 or 6 pellets per square foot - so it goes a very long way. Never pile it up, never ring a plant, and never put it out in a dish. That's how animals get sick because there is too much of it available for them to eat that way.

There are a lot of myths out there about metaldehyde bait, but it really can be safe, especially when you use only the small amount needed. Some will say it kills worms, but I can tell you we have no shortage of worms here, and in fact, too many worms can do extensive damage to gardens.

Yes, they work the same way. The slug will ingest the metaldehyde and die quickly, turning into a pile of slime very fast.