Even if we’ve done it every year for decades, it never hurts to have a primer to jog our memories about basic planter maintenance measurements.
- Most brands of planter disk openers measure 15” when new. Mechanics recommend changing when openers are worn to 14-1/2”.
- When disk openers are changed, it’s best to also change the cast iron inner scraper (aka, “frog”) that dangles vertically between the disk openers. Compare the width of a new scraper to a worn scraper to identify wear and justify the extra expense.
- New disk openers should contact each other at their lower leader edges for 2” to 2-1/2”. Less than 2” of contact allows dirt to fall into the seed furrow and disrupt consistent seed depth. More than 2-1/2” of contact puts excess side-pressure on the disk openers’ bearings.
- Gauge wheel tires in the raised, planting position should have no more than 1/16” clearance between their lipped edge and their disk opener. Faint contact between tire and opener is preferred. Wider gaps encourage dirt to fall in the seed furrow and reduce the ability of the tire’s edge to “squeegee” damp dirt from the opener.
More planter prep help:
Spring Planter Prep: 5 Common Problems, Uncommon Causes and Solutions
Your 19-Point Planter Checklist to Ensure Smooth Spring Planting


