Potatoes are easy to grow and fun to harvest. Grow certified seed potatoes in soil high in organic material, water lightly, and avoid eating any that are green.
- Modified stem (tuber)
- Cool season perennial grown as an annual
- Native to the Andes region of South America
WHEN TO PLANT
- Plant potatoes as early as February and as late as May.
- Tuber production occurs underground until soil temperatures reach 80 degrees.
- Plant only certified seed potatoes to avoid disease.
- Cut large tubers into chunks about 1½ inches in size with at least two eyes. Spread the chunks on newspapers in a warm well-ventilated place to callus for a few days before planting. Small potatoes the size of an egg can be planted whole.
- Plant 3 inches deep and 6 to 12 inches apart.
- When the plant is 6 inches tall, cover with another 3 inches of soil. This is called hilling and can be done again after 6 more inches of plant growth. Hilling increases production and prevents greening.
- Potatoes are easily grown in containers.
- Plant in loose, light, well-drained soil high in organic matter such as aged manure or compost.
- Unlike most vegetables, potatoes prefer slightly acidic soil. (pH 6.0 to 6.5).
- Water lightly once or twice a week, just enough to keep the soil from cracking and to avoid rot.
- Stop watering when the plant turns yellow and begins to die back.
- If organic matter is inadequate, use fertilizer with more phosphorus and potassium than nitrogen.
- Excess nitrogen promotes leaf growth at the expense of potatoes.
- Potatoes mature in 90 to 120 days.
- Harvest can be spread out over several weeks.
- “New” (young) potatoes can be harvested soon after the plant starts flowering, but be careful when you peek to not damage the plants.
- When 20% to 100% of leaves have yellowed, harvest potatoes by digging well back from the plant stem. Discard green potatoes as they contain a high level of toxic alkaloid solanine.
- Alternatively, cut off the plants at ground level and leave the crop in the ground for another couple weeks without watering to harden off the skin.
- Store potatoes in a cool, well-ventilated place. Exclude light to prevent greening.
- Use within six weeks for best flavor and texture.
GOOD VARIETIES FOR MARIN
- ‘Buffalo,’ ‘Bison,’ ‘Carola,’ ‘Carlotta,’ ‘White Rose,’ ‘Kennebec,’ ‘Chieftain,’ ‘Nargold,’ ‘Russet,’ ‘Red Lasoda,’ and ‘Yukon Gold’
- Plant only certified seed potatoes.
- Practice 4-year crop rotation.
- Avoid heavy, wet soil.
- Scab, a fungus, may cause blemishes on the surface. Simply peel off.
- Early and late blight, two fungal diseases, cause plants to collapse and make potatoes inedible. Use certified seed potatoes and avoid overhead watering.
PEST, DISEASE, AND MORE