Potatoes are a cool-weather crop, but the leafy tops can’t tolerate more than a light frost. Plant potatoes so they come to harvest when the weather is cool but not cold.
In cold-winter climates, plant seed potatoes in the garden in spring as soon as the soil can be worked—usually about 3 weeks before the last frost– for harvest in summer. In mild-winter climates, plant potatoes in fall for a winter or spring harvest.
Potatoes will begin to grow as soon as the soil temperature reaches 45°F (7°C). Potatoes very nearly stop growing when the daytime temperatures rise to greater than 80°F (26°C).
Potatoes mature in 45 to 80 days depending on the variety. Time the planting so that tubers come to harvest in cool weather.
Potato Sowing and Planting Tips
- Grow potatoes from certified organic, disease-free seed potatoes. Plant small whole seed potatoes or plant large seed potatoes cut into pieces, each with one to two eyes or growing points, attached to part of the fleshy tuber. (Grocery store potatoes are usually treated to inhibit sprouting so they are not a viable choice for planting.) Before planting, cut pieces should be dried overnight to prevent rotting.
- Potatoes will begin to grow as soon as the soil temperature reaches 45°F (7°C). They can be planted 3 to 2 weeks before the last frost—earlier if protected by a plastic tunnel or cold frame. Planting should be timed so that tubers are harvested before daytime temperatures reach 80°F (26°C) or warmer.
- Sow pieces cut side down in a 4-inch-deep (10 cm) trench in heavy soil or a 6-inch-deep (15 cm) trench in light soil then cover with 2 to 4 inches of soil.
- Space seed potatoes 12 inches (30 cm) apart.
- Optimal soil temperature for growing potatoes is 60-65°F (16-18°C).
- Keep the soil just moist; do not overwater.
- Potatoes prefer a soil pH range of 5.0 to 6.5.
- Grow potatoes in full sun for best yield.
- When leafy tops are 12 inches (30 cm) tall, “hill” them by drawing soil up around the plants so that just the top few leaves are visible above the soil. Hilling will keep developing tubers from exposure to light which can turn them green. You can hill potatoes more than once as plants grow.
- Commonly when plants flower tubers have begun to form underground, but some potato plants produce tubers without flowering.
- Fertilize potato plants with an organic fertilizer that has a higher phosphorus and potassium content than nitrogen.
- A common potato pest enemy is the Colorado potato beetle.
Container Growing Potatoes: Grow potatoes in a container at least 30 inches (76 cm) deep and 20 inches (51 cm) across. Place 10 inches (25 cm) of soil at the bottom of the container then place sprouted seed potatoes on top of the soil and cover with 2 inches (5 cm) of soil. Using the “hilling” process, allow the plants to grow 6 inches (15 cm) then cover again with 2 to 3 inches of soil. Continue this process, allowing the plants to grow about 6 inches before covering half of the leaves with soil again.
Potato Planting Calendar
- 8-6 weeks before the last frost in spring: plant seed potatoes under a plastic tunnel or cold frame.
- 3-2 weeks before the last frost in spring: plant seed potatoes in the open garden; minimum soil temperature is 45°
- Every 4 weeks until 12 weeks before the first frost in fall plant succession crops.
For Fall Harvest:
- 14-12 weeks before the first frost in fall: plant seed potatoes.
Types of Potatoes and Recommended Varieties
There are several types of potatoes. Choose types and varieties to grow based on how you plan to use the potato. Here are several potato types:
- Russet, also called baking potatoes or Idaho potatoes: elliptical shape, 4 to 6 inches long; use for boiling, baking or deep frying.
- Fingerlings: thumb-sized can be baked, boiled, steamed, fried, and roasted. Varieties include ‘Ruby’, ‘Russian Banana’, and ‘Long White.’
- Yellow: round to slightly oblong with thin, yellowish skins, and buttery yellow flesh; they can be boiled, steamed, mashed, roasted, and grilled. Varieties include ‘Yukon Gold’, ‘Yellow Finn’, and ‘German Butterball.’
- Round white: medium-sized with light tan to freckled brown skin and waxy to creamy textured flesh; they can be boiled, roasted, fried, and mashed. Varieties include ‘Kennebec’, ‘Superior’, and ‘Atlantic.’
- Round red also called boiling potatoes: medium-sized, dense, crisp white flesh; use for boiling, roasting, grilled. Varieties include ‘Norland’ and ‘Pontiac.’
Botanical Name: Solanum tuberosum
Potatoes are a member of the Solanaceae family; other members of this family are tomatoes, eggplants, and peppers.
