How to Plant Potatoes in Greenhouses

Planting potatoes in a greenhouse is an excellent way to grow very early potatoes in the UK. A greenhouse warms up quickly in late winter and early spring, allowing you to plant weeks before outdoor conditions are suitable and enjoy fresh new potatoes much earlier.

⭐ Recommended Products — Seed Potatoes & Planting Essentials

• Seed Potato Collection (Early, First & Second Earlies)
A mixed pack of quality seed potatoes to plant for a steady harvest from early summer through to autumn. Ideal if you want variety in size and maturity times.
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• Certified Seed Potatoes (Single Variety Packs)
Choose popular individual varieties (e.g., Maris Piper, Charlotte, King Edward) to suit your taste and growing goals — consistent results from true seed stock.
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• Potato Grow Bags / Containers
Reusable, breathable bags designed specifically for growing potatoes — great for patios, small gardens, or increasing yield in limited space.
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• Potato Fertiliser / Soil Booster
Specially formulated feed to support healthy tuber development and improve yields — apply at planting or as a top-dress during the season.
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• Potato Planting Guides & Markers
Helpful tools and guides that take you through planting depth, spacing, and care — plus reusable markers to keep track of different varieties.
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Why Grow Potatoes in a Greenhouse?

Greenhouse potato growing:

• Allows much earlier planting
• Produces earlier harvests
• Protects plants from frost, wind, and heavy rain
• Gives better control over watering and temperature
• Works well for small, intensive crops

Greenhouses are best used for early potatoes, not large maincrop harvests.

Best Potatoes to Grow in a Greenhouse

Greenhouses are ideal for:

• First early potatoes
• Second early potatoes
• Salad potato varieties

Maincrop potatoes take too long and use too much valuable greenhouse space.

Good choices include fast-growing and compact varieties.

When to Plant Potatoes in a Greenhouse

In the UK, greenhouse potatoes can be planted:

• Late January to February (first earlies)
• February to early March (second earlies)

This is typically 4–8 weeks earlier than outdoor planting, depending on weather and greenhouse insulation.

Step 1: Choose Containers or Beds

Potatoes in greenhouses are best grown in:

• Large pots
• Grow bags
• Buckets
• Raised greenhouse beds

Containers should be:

• At least 40–45 cm deep
• Have excellent drainage

Growing in containers makes temperature and moisture control easier.

Step 2: Prepare the Compost or Soil

Use a light, fertile growing medium:

• Peat-free multipurpose compost
• Optional: mix in well-rotted garden compost

Avoid heavy garden soil on its own, as drainage is crucial in a greenhouse.

Step 3: Chit Seed Potatoes

Chitting is strongly recommended for greenhouse growing:

• Start chitting 4–6 weeks before planting
• Aim for short, sturdy shoots (1–2 cm)

Chitted potatoes take full advantage of the warmer conditions.

Step 4: Plant at the Correct Depth

• Add 10–15 cm of compost to the container base
• Place seed potatoes on top
• Shoots (chits) facing upwards
• Cover with another 10–15 cm of compost

Do not fill containers to the top at planting time.

Step 5: Space the Potatoes Correctly

• Containers: 1 potato per 10–15 litres of compost
• Beds: 30 cm apart for early varieties

Avoid overcrowding, as this reduces yield and airflow.

Step 6: Water Lightly After Planting

• Water gently if compost is dry
• Do not overwater
• Cold, wet compost can cause seed potatoes to rot

Greenhouses dry out quickly later, but early on moisture should be controlled.

Step 7: Frost Protection Inside the Greenhouse

Even in a greenhouse, frost can occur.

• Use fleece over containers on cold nights
• Bubble-wrap the greenhouse if needed
• Keep doors closed during frosts

Young potato shoots are very frost-sensitive.

Step 8: Earth Up as Plants Grow

When shoots reach 10–15 cm tall:

• Add more compost around stems
• Leave the top leaves exposed
• Repeat until containers are nearly full

This prevents greening and increases yields.

Step 9: Ventilation and Temperature Control

As days warm up:

• Open vents and doors on sunny days
• Avoid overheating
• Good airflow reduces disease risk

Potatoes prefer cool to mild conditions rather than high heat.

Step 10: Watering and Feeding

• Water little and often
• Never allow compost to fully dry out
• Feed lightly once flowering begins with a balanced fertiliser

Avoid high-nitrogen feeds, which cause leafy growth at the expense of tubers.

Step 11: Harvesting Greenhouse Potatoes

• First earlies: Harvest when flowering begins
• Second earlies: Harvest just after flowering

Greenhouse potatoes can be ready:

• As early as April or May, depending on planting time

To harvest:

• Tip out containers
• Gently collect potatoes by hand

Common Mistakes to Avoid

• Planting too early without frost protection
• Overwatering in cool conditions
• Poor ventilation on warm days
• Growing maincrop potatoes in limited greenhouse space

Greenhouse vs Polytunnel Potatoes

• Greenhouse: Earlier harvests, smaller crops
• Polytunnel: Slightly later but larger yields

Both are excellent for early potatoes.

Quick Summary

• Plant January–February
• Use first or second early varieties
• Grow mainly in containers
• Plant 10–15 cm deep
• Earth up regularly
• Ventilate well
• Harvest weeks earlier than outdoors

Final Tip

If you want the earliest possible potatoes in the UK, greenhouse growing is hard to beat. Focus on early varieties, protect from frost, and manage temperature carefully for delicious new potatoes long before outdoor crops are ready.