I'm putting down Sevin Insect Killer on my lawn with a Speedy-Green spreader and the setting doesn't seem right to me. The bag shows Sta-Green settings (not Speedy-Green) so I'm converting. To apply the desired 4 lbs. per 1,000 sft the bag says the Sta-Green setting should be 9. I believe converting Sta-Green to Speedy-Green requires a factor of 1.33, resulting in a Speedy-Green setting of 12 (9 x 1.33), which seems very high to me. Thoughts, please.

 

All of those spreader settings are just wild suggestions at best. How much actually comes out can vary greatly depending on the age of the product and how it was stored. Humidity can have a big impact on many products by affecting how quickly it flows out of the hopper.

The only way to know for sure is to measure. Mark out a 100' x 100' area on your lawn. Weigh how much product you put in the hopper. Then go spread on your measured area, come back and weigh how much is left in the hopper. Then you'll know your actual application rate. But... nobody actually does that so your stuck with using your best judgement.

I intentionally use a low setting. I shoot for having to make 3-4 passes to dispense all the product. This mitigates a lot of the inaccuracy in the hopper metering and if you run a different pattern with each pass you greatly minimize the chances of under applying one area or over applying on another. If the hopper runs out before you finish the lawn you've already made 3 passes over the area so it's gotten close to a full does. If you try to do the lawn in only one pass and come up short you'll have over applied to most of the lawn while part receives nothing.