I get questions every year about when to use talc in planters, when to use graphite, and when to use a blend of talc and graphite. Understand what each product answers and it’s easier to understand which to use, and where.
Talc attracts moisture. When mixed with seed, especially seed with sticky seed treatments, the talc helps keep the seeds from clumping. A vacuum planter or a central fill planter that plants great one day but suddenly starts planting inaccurately the next morning may simply be due to higher humidity in the morning air clumping the seeds. A dose of talc can work magic in those situations.
Graphite is a dry lubricant, and recommended for planters that use finger-style seed meters. There’s lots of metal-to-metal contact in those seed meters, so talc reduces wear and lubricates movement without the gummy residue of oily lubricants.
Blended talc and graphite is popular because it not only combines the drying of talc with the lubrication of graphite, but helps central fill planters that use plastic hoses to deliver seed from the tanks to individual row units. In dry weather all those seeds tumbling through the tubes can create static electricity. Just as static electricity can make your hair stand on end, it encourage seeds to clump together or cling to the sides of the seed transfer tubes enough to increase problems with plugged tubes. Graphite is a great conductor of electricity, so using a blend of graphite and talc not only dry-lubricates the insides of the tubes, but also reduces problems with static electricity by lining the inside of the tubes with a conductive layer of graphite.
