Why should I avoid planting store-bought potatoes?
Written by
Olivia Mitchell
Reviewed by
Prof. Samuel Fitzgerald, Ph.D.Planting grocery store potatoes can doom your crop and inflict devastating disease problems on your garden soil. That's the lesson I learned many vintages ago when everything rotted. Infected commercial tubers often harbor parasites that can persist in the soil for 4-7 years and on equipment. There are sprout inhibitors that reduce germination by 60 percent, as well as late blight (up to 40 percent of PC), among other benefits.
Disease Transmission
- Grocery potatoes: 60-80% carry latent blight spores
- Certified seeds: Lab-tested for 0% disease presence
- Soil contamination lasts 7 years affecting future crops
Growth Performance
- Grocery potatoes: 30-50% lower germination rates
- Certified seeds: 95%+ sprouting success
- Yield difference: 1-3 lbs vs 8-15 lbs per plant
Sprout inhibitors on supermarket potatoes prevent them from sprouting. The chemicals used remain active for months, and I've had potatoes that I forgot about not grow even once. Certified seeds receive rigorous field inspections and laboratory testing and offer guarantees for clean starts to healthy plants.
Be sure to ask for the certification tag when buying seed potatoes; reputable dealers will provide them. Cut them into egg-sized pieces having 2 or 3 eyes each. Curing the cuts for 48 hours before planting will induce vigorous sprouting.
Plant Rotation Schedule - Change your planting location every year! Never plant tomatoes or peppers after planting potatoes; they share several diseases with potatoes. Store any leftover certified seed potatoes in a dark, cool area at 40°F (4°C); the seeds will remain viable for the next planting season, but store-bought potatoes are no longer feasible.
Read the full article: How to Grow Potatoes: Essential Gardening Guide
