What month is best for planting potatoes?
Written by
Michael Sullivan
Reviewed by
Prof. Charles Hartman, Ph.D.Timing plant potatoes involving soil temperature rather than solely a date on the calendar. I learned this lesson the hard way when I lost a crop to frost in April. Soil probes are better than guesswork. Zones 3-5 should plant potatoes after the danger of frost past. Coastal zones 7-9 can be planted earlier. Be aware of the patterns of your microclimate.
Soil Preparation
- Test pH 5.0-6.5 with digital meter
- Mix 3" compost into clay soils
- Add sulfur if pH exceeds 7.0
Water Management
- 1-1.5" water weekly until flowering
- Reduce to 0.5" during tuber growth
- Drip irrigation prevents leaf diseases
Regional Timelines
- Zones 3-5: Mid-April to May 10
- Zones 6-7: March 25-April 15
- Zones 8-10: August 1-September 5
Soil temperature determines the success of your garden. I always plant when soil thermometer probes indicate 45°F at 6" depth. Cold temperatures do not allow seeds to sprout above ground or germinate below ground. Black plastic warms the soil in my Zone 6b garden. Southern growers use shade cloth to prevent soil temperatures from becoming too warm. Balance is the key.
Fall planting alters customary routines. For example, in Arizona, I plant Red Pontiac potatoes in September so I can harvest before frost in December. Gardens on the coast, in California, utilize the patterns of the fog. Use wireless sensors to help track rainfall. This will assist you in modifying watering protocols during the monsoon seasons.
Read the full article: When Plant Potatoes: Expert Timing Guide
