How to grow potatoes for a generous harvest in beds, bags and barrels

Potatoes are one of the most satisfying crops a home grower can try. A few seed tubers can turn into a bucket of food, and the process is surprisingly straightforward once you understand their needs.

This guide walks through choosing seed potatoes, preparing soil, planting, earthing up and harvesting, with options for both open ground and confined spaces like bags or barrels.

Choosing the right seed potatoes

For reliable results, start with certified seed potatoes rather than supermarket tubers. Certified seed is checked for common diseases and usually gives stronger growth and better yields. Supermarket potatoes often carry viruses or are treated to prevent sprouting.

Potato varieties are usually grouped by cropping time. Early types are harvested young for waxy new potatoes, second earlies follow a few weeks later, and maincrop varieties are left to bulk up for storage. Choose at least one early and one maincrop so you can enjoy both fresh meals and a longer keeping harvest.

Chitting and timing your planting

Many growers like to “chit” seed potatoes: placing them in a bright, cool spot so they develop short, sturdy sprouts before planting. Set the tubers in egg boxes or shallow trays, eyes facing up, and keep them at around 7–10 °C. In 4–6 weeks you should see compact shoots.

Planting time depends on your climate. In cooler regions, planting often starts in early to mid spring once the soil is workable and not waterlogged. In milder climates, you may be able to plant a little earlier. Avoid very cold, saturated soil, which slows growth and encourages rot.

Soil preparation for healthy roots

Potatoes thrive in loose, moisture retentive but well drained soil. Heavy clay can lead to misshapen tubers, while very sandy ground dries out too quickly. Aim for a crumbly structure that you can dig through easily with a hand fork.

Before planting, remove perennial weeds and incorporate well rotted compost or aged manure. Fresh manure can cause scab and forked roots, so apply it in the previous season if possible. Potatoes prefer slightly acidic conditions, so avoid liming the area just before planting.

Planting in open ground

For beds, a simple trench method works well. Mark out rows about 60–75 cm apart for maincrops and a little closer for earlies. Dig a shallow trench about 10–15 cm deep and lightly fork in compost if the soil is poor.

Place seed potatoes in the trench with the sprouts facing upward. Space early varieties about 25–30 cm apart, and maincrops 30–40 cm apart. Cover gently with soil, then water if the soil is dry. As shoots emerge, you will gradually build the sides of the row into a low ridge.

Growing in bags, barrels and boxes

Where space is limited, potatoes adapt well to deep containers, fabric grow bags or bottomless barrels. Choose a sturdy vessel at least 35–40 cm deep with drainage holes. Fill the bottom with 10–15 cm of a mix of compost and garden soil or compost and sharp sand.

Set three to five seed potatoes on the surface, then cover with another 10–15 cm of mix. As the foliage grows, keep adding material around the stems, leaving the top leaves exposed. This creates more space for tubers to form while also shading them from light.

Watering, feeding and earthing up

Consistent moisture is essential while tubers are forming. Water deeply once or twice a week in dry periods, aiming to keep the soil evenly damp but not soggy. Irregular watering can lead to cracked tubers or hollow centers.

When the shoots reach about 15–20 cm, start earthing up. Pull loose soil (or your container mix) around the stems to bury the lower leaves, forming a ridge. Repeat every couple of weeks until the ridge is 20–30 cm high. This protects developing tubers from light, which turns them green and bitter, and helps control weeds.

If your soil is reasonably fertile and you added organic matter, extra feeding is often unnecessary. In poor soils, a balanced, slow release fertilizer applied at planting can support growth. Avoid high nitrogen products, which encourage leafy growth at the expense of tubers.

Managing pests and common problems

Slugs and snails can damage tubers and foliage, especially in damp conditions. Encouraging natural predators like beetles and birds, using physical barriers, and keeping the area weeded all help to reduce hiding places. Lifting crops promptly once mature also limits slug damage underground.

Potato blight is a serious fungal-like disease that appears in humid weather, causing dark patches on leaves and stems. Good airflow, adequate spacing and removing lower leaves that touch the soil can slow its spread. If blight strikes hard on maincrops, cut off and remove the haulms (tops) to ground level, then wait two weeks before lifting tubers so the skins can set.

When and how to harvest

Earlies are usually ready when plants begin to flower and the tubers reach egg size, often about 10–12 weeks after planting. Loosen the soil carefully by hand or with a fork, feeling for usable potatoes while leaving tiny ones to grow for another week if needed.

Maincrops are usually lifted once the tops yellow and die back. For storage, wait until the foliage has completely withered, then dig on a dry day. Let the tubers dry briefly on the surface, protected from direct sun, and brush off loose soil without washing.

Storing your crop

Only sound, undamaged tubers store well. Allow them to cure in a cool, dark, airy place for a week or two. Then transfer them to breathable sacks or crates and keep them somewhere cold but frost free, such as an unheated room, cellar or insulated shed.

Check stored potatoes regularly and remove any that soften or sprout heavily. With the right variety and storage conditions, a modest patch or a few bags can supply meals for many weeks after harvest.