One of the most satisfying moments in the edible garden is taking a garden fork and gently pushing it under a clump of potatoes. Lift up the fork and, as the soil falls away, you’ll discover a mass of potatoes.

Potatoes are one of the oldest crops dating back to Peru and the Incas, who were the first people known to grow the crop. The humble spud as its commonly known, consists of 80 per cent water and 20 per cent solids.

Variety is the spice of life for the potato, with more than 100 different types. They are packed full of vitamins and minerals, although the variety and the way it’s cooked can affect the nutrient value. By peeling it for mash, the nutrient content is greatly reduced.

Follow our seven easy steps to successful potato harvest including tips along the way.

Woman holding a handful of rich fertile soil

When to plant and location.

When to plant.

Potatoes can be grown in most parts of Australia. Check with garden centres and hardware stores for varieties in your local area.

In warm, frost-free areas potatoes are grown year round but crops are best planted in late winter to late summer.
In subtropical and tropical zones grow potatoes in the dry season.
In cold areas, particularly with late frosts, hold off planting potatoes until spring. A second crop can be planted in summer.

Location.

They grow best in full sun (or with light afternoon shade in hotter climates) in soil that holds moisture well.
Where there’s little space, grow potatoes in a large pot, sack, raised bed or cylinder. Above-ground options also work well in areas with poorly drained soil.
Ensure crop rotation in the garden by growing potatoes in different plots in each year away from previous Solanaceae crops such as tomato.

Soil.

Potatoes grow in most soils but before sowing, dig over the soil to remove stones, clods or old roots along with weeds.
To improve the water-holding capacity of the soil, work in well-rotted organic matter or apply Seasol Liquid Compost.
In heavy soils with poor drainage, work in lots of organic matter to develop a good friable soil for potatoes.
The pH of the soil should be around 5.0 to 6.0. Potatoes will do ok in slightly acidic soil but will not do well in alkaline soil (greater than 7.0) as many of the nutrients required to grow a potato are not available.
Apply Seasol Plant + Soil Booster and mix it into the topsoil.
Water in well and if possible, let the soil rest for a week or so.

Step 1 – Prepare tubers.

Before planting encourage seed potatoes to sprout by ‘chitting’.
Place seed potatoes on a rack or in a cardboard egg box in a warm bright spot.
Small shoots soon form from the eyes and they are ready to plant.
Seed potatoes can also be planted without this step.

Step 2 – Planting preparation.

In the garden, dig trenches about 15cm deep and mound up the dug soil.
Space rows 75cm apart.
In a container or bag, fill the bottom 15cm with good quality potting mix like Seasol Garden Soil Mix.
Fold back the bag to allow the sun and moisture to get to the soil.

Step 3 – Planting tubers.

In the garden, place chitted tubers into the prepared trench about 30-40cm apart.
In the container or bag, space the tubers around the bag ensuring there is enough room for them to grow.
Cover the tubers with soil so just the tips of the sprouted shoots are showing.
Water in well with Seasol to reduce transplant shock and promote healthy growth and strong tuber development. Mix 30mL of Seasol concentrate per 9 litres of water.

Step 4 – Potato plant growth.

As the shoots grow, cover them every two weeks with more soil.
Remove weeds regularly by hand weeding or hoeing between the rows.
Water well and spread mulch around plants to keep moisture in and weeds away.
Apply a liquid fertiliser occasionally that is low in nitrogen (for less leafy growth) and higher in phosphorus and potassium (more tuber development) such as PowerFeed PRO SERIES for Roses & Flowers.

Step 5 – Ongoing potato care

Continue to earth up around the potatoes until the trench is refilled.
If growing in a bag, unfold the sides of the bag to support the soil and potatoes.
Continue earthing up around the stems fortnightly until the plants are tall and leafy.
Keep plants well watered and apply Seasol every two weeks.

Step 6 – Potato tuber formation.

Potatoes form stems of leafy growth above ground while beneath the soil the roots form small tubers.
Potato roots must be in the dark to ensure good tuber formation. Ensure the roots are covered with soil at all times.
Remove weeds and ensure mulch is topped up.
Continue to apply PowerFeed PRO SERIES Roses & Flowers every 2 to 4 weeks for strong, healthy growth.
Potatoes will take 14 to 20 weeks to harvest from planting.

Step 7 – Potato harvest.

When the potato plants start to flower small tubers can be carefully harvested as new potatoes. Leave the plant to grow and the small tubers to develop.
Burrowing under the potato plant to harvest new potatoes is known as ‘bandicooting’.
For large potatoes with a long storage life, wait until the tops start to die back then use a fork to carefully lift the plant from the ground to harvest the crop.

Things to watch for…

Potatoes are subject to pest and disease problems but most can be avoided by planting virus-free tubers known as seed potatoes.

Frost Potato plants are frost sensitive and their leafy growth can be badly damaged by frost. Delay planting until spring to avoid frost damage.
Rats and mice Rodents can burrow into the bed and gnaw on the potatoes before harvest.
Slugs and snailsThese pests may damage the leaves but rarely the tubers. Keep them at bay with an organic, iron-based snail bait.
Potato scab This disease is favoured by overly dry conditions. Avoid with regular watering.
Potato blights There are various fungal diseases that affect potatoes and cause them to rot before harvest. Remove and destroy any affected plants. Avoid disease with good garden hygiene, well-drained soil and removing all the potatoes at harvest.
Greening of potatoes Exposure to light can lead to the skin and flesh becoming green. Keep potatoes well covered with earth to avoid this and store harvested potatoes in the dark. The green parts are toxic and should not be eaten.