How to Grow Potatoes – The Ultimate UK Guide to Soil Prep, Planting, and Care
Growing your own potatoes is one of the most rewarding projects you can take on in the garden. There is nothing quite like the taste of freshly dug spuds lifted straight from the soil. Whether you have a sprawling allotment or just a few patio potato bags, this comprehensive guide will take you from bare soil to a bumper harvest.
What You'll Need
- Certified virus-free seed potatoes
- A Wooden Potato Chitting Tray
- A heavy-duty garden spade and garden fork
- High-quality multi-purpose compost or well-rotted manure
- Organic potato fertiliser
- Sharp garden secateurs
Phase 1: Preparing the Planting Area
Potatoes are hungry crops that love loose, deeply dug, nutrient-rich soil. If your soil is compacted, your potatoes will end up small and misshapen.
1. Deep Digging
Before planting, dig over your chosen plot to a depth of at least one spade blade (about 30cm). Remove all perennial weeds, large stones, and old roots. This gives the expanding tubers plenty of room to push through the soil without resistance.
2. Adding Organic Matter
Potatoes need soil that retains moisture but does not get waterlogged. Incorporate a generous amount of organic matter as you dig. Well-rotted garden compost or farmyard manure will improve soil structure and help retain moisture through the growing season.
3. Adding Fertiliser at Planting Time
Potatoes are heavy feeders that need plenty of fuel. When you dig your planting trenches (about 10–12cm deep), sprinkle a dedicated slow-release organic potato fertiliser along the bottom before placing your seed potatoes. Look for a fertiliser high in potassium (potash), which directly fuels tuber development.
Phase 2: Chitting and Planting Out
Before your potatoes go into the ground, give them a head start through a process called chitting ,encouraging the potatoes to sprout strong, healthy shoots before planting.
How to Chit: Stand your seed potatoes upright in a Wooden Potato Chitting Tray, with the end containing the most "eyes" (small dimples) facing upwards. Place the tray in a cool, bright, frost-free spot such as a greenhouse or porch. Within a few weeks, strong green shoots will appear. Once these shoots are around 2cm long, your potatoes are ready to plant.
Why use a proper chitting tray? Old cardboard alternatives easily become soggy and tip over. A sturdy Wooden Potato Chitting Tray keeps your seed potatoes perfectly upright, allows light to reach all sides, and can be moved around without damaging the delicate new sprouts.
Planting: Place the chitted seed potatoes in your fertilised trench, spaced 30cm apart, with the sprouts pointing upward. Gently cover them with your loose, enriched soil.
Phase 3: The Crucial Step – Earthing Up
As your potato plants grow and the green stems reach about 10–15cm above the ground, you must earth up. This involves using a spade or hoe to draw the loose soil from between the rows up around the stems, creating a long ridge-like mound. Repeat this two or three times over the growing season as the plants grow taller.
Why Do We Earth Up?
- More potatoes: Potatoes grow from underground stems. By mounding soil higher around the main stem, you create more underground growing space, meaning significantly more potatoes per plant.
- Protection: It keeps the developing potatoes in complete darkness, which leads us to our most important safety point.
⚠️ Why Green Means Stop
When a potato is exposed to sunlight, it produces green chlorophyll and triggers a natural compound called solanine, the potato's built-in defence mechanism. Because the potato senses it is exposed, it makes itself bitter to deter insects and birds.
The golden rule: If you see green, do not eat it. Never eat any potato showing green colouring, no matter how small the patch. Solanine can cause a severe stomach upset, and unfortunately neither boiling nor roasting will neutralise it. If a spud has turned green, put it straight on the compost heap.
Phase 4: Watering and Blight Prevention
Potatoes are mostly water, so consistent moisture is essential, particularly once the plants begin to flower, which signals that tubers are forming underground. Always water at the base of the mounds to deliver moisture directly to the roots.
Outsmarting Potato Blight
Potato blight is a fungal disease that thrives in the warm, damp conditions of mid-to-late summer. It causes dark brown patches on the leaves and can devastate a harvest. Protect your crop with these steps:
- Water the soil, not the leaves: Blight spores need moisture on the leaf surface to take hold. Keep the foliage dry.
- Give them space: Leave 30cm between plants and 60cm between rows to ensure good airflow.
- The cut-and-drop method: If you spot blight spreading across the leaves, use a pair of sharp secateurs to cut all the green foliage down to ground level immediately. Dispose of the leaves, do not compost them. Leave the potatoes underground for a further two weeks to allow the skins to harden before lifting.
Phase 5: Troubleshooting Common Pests
Keep an eye out for these three common visitors in UK gardens:
- Slugs: These underground nibblers drill neat holes into developing potatoes. The fix: Keep the soil well-aerated with a garden fork, or use wildlife-safe organic slug pellets around the base of your plants.
- Common Scab: Causes rough, corky patches on the skin. The fix: Scab is completely harmless and does not affect the flavour, simply peel before cooking. It tends to occur when soil is too dry, so keep plants well watered.
- Wireworms: Golden-yellow larvae that tunnel through spuds, common in plots converted from old lawns. The fix: Turn the soil thoroughly during spring preparation and let robins and blackbirds do the rest.