At a glance
Ease of culture: Moderate
Where: All regions
Best climate: Cool to warm conditions
When: Spring, summer, autumn in cool areas, winter in warm to hot areas
Harvest: 3-5 months
• Potatoes prefer cool mild conditions with daytime temperatures between 15-20° C
• They grow best in cooler areas, planted in spring (after last frost) and late summer/early autumn.
• If living in hot climates, grow through the cooler months – plant autumn-winter
• Find a spot with full sun (at least 6 hours per day) and protection from strong winds
Box: Seed Potatoes
Start your crop with the very best planting material. Don’t plant spuds bought from the supermarket or green grocer. Instead, plant 'seed potatoes" that are certified virus-free. This avoids the potential of introducing a nasty virus to your soil and assures you the best potential harvest. Certified seed potatoes are available from nurseries and produce stores or try mail-order companies, where you’ll find the greatest range of varieties.
Preparing planting stock
• Expose seed potatoes to light (not direct sun) before planting to encourage them to shoot
• Large seed potatoes can be can be sliced to create more planting stock – just be sure each section has at least one shoot. Let them sit for a few days to allow the cut surfaces to dry before planting or they may rot.
The traditional way to grow potatoes is in the soil, but you can also grow them in containers or a no-dig garden.
In the soil
• Use a garden fork to loosen the soil to a spade’s depth, and then dig in plenty of compost or well-rotted manure – at least 2 bucketfuls per square metre.
• To improve drainage, mound the soil in planting rows with centres 40-50cm apart
• Dig narrow trenches along the centre of the mounds 10-20cm deep
• Place seed potatoes along the trenches 25-30cm apart, shoots facing upwards
• Cover the seed potatoes with a 10cm layer of soil and water in well.
Box: Hilling for better returns
As the potato shoots begin to grow above the soil surface, gradually cover them with soil. This process, known as hilling, encourages the plants to form more roots along the buried stems on which more potatoes will form, increasing overall yield.
• Find a spot in the garden where the ground is well drained
• Mark out a growing area – 1.2m x 1.2m is a good size to start, or go bigger
• Cover the area with 6-7 sheets of newspaper, overlapping the edges to smother the weeds and grass. Wet it to stop it blowing away.
• Place your seed potatoes on the surface, 25-30cm apart.
• Cover the potatoes with thin layers of compost, and other organic materials like well-rotted manure, sawdust, old grass clippings, and dry leaves – whatever you’ve got. Water each layer as you build it up to a final depth of 20cm.
• Add more layers as the potatoes grow and the materials break down. After a month or so, add a final layer of straw 10-15cm thick.
• Choose a big container – at least 30cm wide and deep – the bigger, the better.
• Plastic pots are good, old laundry tubs, wheel barrows or even old hessian bags – whatever you choose, ensure it has adequate drainage holes.
• Prepare your growing medium. Potting mix is okay, but a 50/50 blend of potting mix and compost is better.
• Tip a 10cm layer of growing medium into your container, then lay your seed potatoes on the surface, 25-30cm apart, with the shoots pointing upwards.
• Cover the seed potatoes with another 10cm layer of growing medium and water the mix well.
• As the shoots develop, gradually cover the stem with more mix – up to an additional 40cm deep.
• Finally, cover the mix with a mulch of straw to help hold in moisture
Watering and fertilising
• Attention to watering is critical. Lack of adequate moisture with result in a poor crop whereas too much water will cause tubers to rot. Maintain a regular soil moisture level – it should feel slightly damp to touch, not soggy.
• Fertilising your potato crop will provide better returns. Give plants a light application of an all-purpose organic fertiliser after planting. Follow up with another application after six weeks.
• You can start to harvest potatoes any time after about 8 weeks, by digging around plants while they’re still growing and grabbing a few new or small potatoes.
• The longer the plants are left to grow, the bigger the potatoes will grow.
• The best time to complete harvesting is when the tops have died down – and no more tubers will develop.
• Use a garden fork to gently loosen the soil to reveal the potatoes – be careful not to stab them
• Let them dry on the ground before brushing off excess soil ready for storing (do not wash them – this shortens storage time)
• Store in a dark airy space
• Eat damaged spuds first.