Seed Potatoes: When to Plant for a Successful Potato Harvest

Planting seed potatoes at the right time is essential for achieving a productive and healthy crop. Seed potatoes, which are specially grown and certified disease-free tubers, need to be planted based on their variety, the growing season, and your local climate. Proper timing ensures optimal growth, reduces the risk of frost damage, and maximizes your potato yield.

This guide provides a detailed overview of when to plant seed potatoes, including tips for first earlies, second earlies, maincrop, and salad potatoes.

When to Plant Seed Potatoes by Variety

1. First Early Potatoes

• Planting Time: Late February to early March.
• Harvest Time: 10–12 weeks after planting (typically late May to June).
• Best For: Early harvests and new potatoes.
• Examples: Rocket, Swift, Arran Pilot.

2. Second Early Potatoes

• Planting Time: Mid-to-late March.
• Harvest Time: 13–15 weeks after planting (typically late June to early July).
• Best For: Mid-season crops and salads.
• Examples: Charlotte, Kestrel, Maris Peer.

3. Maincrop Potatoes

• Planting Time: Late March to early April.
• Harvest Time: 18–20 weeks after planting (typically late August to September).
• Best For: Large harvests and long-term storage.
• Examples: Maris Piper, King Edward, Desiree.

4. Salad Potatoes

• Planting Time: Mid-March.
• Harvest Time: 12–14 weeks after planting (typically June to July).
• Best For: Waxy-textured potatoes for salads and cooking.
• Examples: Pink Fir Apple, Nicola, Ratte.

Factors to Consider for Planting Seed Potatoes

1. Local Climate

• Mild regions can start planting earlier in February or March, while colder areas may need to wait until late March or April.
• Use fleece or cloches to protect young plants from late frosts.

2. Frost Risk

• Avoid planting seed potatoes outdoors until the risk of frost has passed. For most areas, this is late March to early April.

3. Soil Conditions

• Potatoes thrive in well-drained, fertile soil with a pH of 5.5–6.5.
• Ensure the soil is workable and not waterlogged before planting.

How to Prepare Seed Potatoes for Planting

1. Chitting Seed Potatoes

• When to Start Chitting: 4–6 weeks before planting (typically in January or February).
• How to Chit:
  1. Place seed potatoes in a cool, bright location with the eyes (sprouts) facing upward.
  2. Allow sprouts to grow to 2–3 cm before planting.

2. Soil Preparation

• Enrich the soil with compost or well-rotted manure to improve fertility.
• Clear weeds and loosen the soil for better aeration and drainage.

Planting Seed Potatoes: A Step-by-Step Guide

1. Planting in the Ground

1. Dig trenches or individual holes about 10 cm deep.
2. Place chitted seed potatoes with the sprouted eyes facing up.
3. Cover with soil, leaving a slight mound to protect against frost.
4. Space seed potatoes as follows:
   • First and second earlies: 30 cm apart with rows 60 cm apart.
   • Maincrop potatoes: 40 cm apart with rows 75 cm apart.

2. Planting in Containers or Bags

1. Fill the container or potato bag with 10 cm of soil or compost.
2. Place 3–5 seed potatoes evenly spaced on the surface.
3. Cover with another 10 cm of soil and water lightly.
4. Add more soil as the plants grow, leaving the top leaves exposed.

Caring for Seed Potatoes After Planting

1. Watering

• Keep the soil consistently moist, especially during dry spells.
• Avoid overwatering to prevent tuber rot.

2. Earthing Up

• As plants grow, mound soil or compost around the stems to protect developing tubers from sunlight and prevent greening.

3. Fertilizing

• Use a balanced fertilizer at planting and during early growth to encourage healthy plants.

4. Frost Protection

• Cover young plants with fleece or cloches if frost is forecast.

Harvesting Seed Potatoes

First and Second Earlies

• Harvest when plants flower or the foliage begins to yellow, typically 10–15 weeks after planting.

Maincrop Potatoes

• Wait until the foliage dies back completely, around 18–20 weeks after planting.
• Use a garden fork to lift the tubers gently to avoid damage.

Tips for Planting Seed Potatoes Successfully

1. Start Chitting Early: Begin chitting in late winter to prepare seed potatoes for early planting.
2. Monitor Frost Dates: Pay attention to local frost dates and protect young plants as needed.
3. Rotate Crops Annually: Avoid planting potatoes in the same spot each year to reduce the risk of soil-borne diseases.
4. Choose the Right Variety: Match your seed potatoes to your desired harvest time and culinary needs.
5. Use Quality Seed Potatoes: Always select certified disease-free seed potatoes for the best results.

Top 10 Questions About Planting Seed Potatoes

1. When should I plant first early potatoes?

Plant first earlies in late February to early March for an early harvest.

2. When is the best time to plant maincrop potatoes?

Plant maincrop potatoes in late March to early April.

3. How do I prepare seed potatoes for planting?

Chit seed potatoes 4–6 weeks before planting by allowing them to sprout in a cool, bright spot.

4. Can I plant seed potatoes in containers?

Yes, seed potatoes grow well in containers or potato bags with proper soil depth.

5. How do I protect seed potatoes from frost?

Cover young plants with fleece, cloches, or a layer of soil if frost is forecast.

6. How far apart should I plant seed potatoes?

Space first and second earlies 30 cm apart and maincrop potatoes 40 cm apart.

7. Can I grow potatoes in small spaces?

Yes, seed potatoes can be grown in containers, making them suitable for patios or small gardens.

8. What happens if I plant seed potatoes too early?

Planting too early increases the risk of frost damage and poor growth.

9. When should I start chitting seed potatoes?

Start chitting in January or February, 4–6 weeks before planting.

10. How long do potatoes take to grow?

Potatoes take 10–20 weeks to grow, depending on the variety.

Conclusion

Planting seed potatoes at the right time ensures a healthy and productive crop. By considering your local climate, the type of potatoes, and the frost risk, you can time your planting perfectly for a successful harvest. Whether you’re growing first earlies for new potatoes or maincrop varieties for storage, proper planning and care will lead to a rewarding gardening experience.