How to Grow Potatoes

There are reportedly around 5000 different types and varieties of Potatoes around the world. Some of the most common Potatoes in Australia are Desiree, Dutch Cream, Coliban, Nadine, Nicola, Pontiac and Royal Blue. Some have white or cream skin, others have pink or red skin.

Different varieties are also better suited to different types of cooking. For example, waxy Potatoes like Dutch Cream are best for roasting and boiling, and starchy Potatoes like King Edward are ideal for chips and mashing.

There are also interesting coloured Potatoes like Purple Congo (which has purple flesh) and Potatoes like Kipfler which have an elongated shape.

Potato plants also differ in the way they grow and can be separated into two groups including indeterminate and determinate varieties.

Indeterminate Potatoes, such as Sebago, can produce multiple layers of tubers (Potatoes) underground, which is why they do best when the soil (or potting mix) is mounded up around them as they grow.

Determinate Potatoes, like Purple Congo, produce tubers in one layer, so mounding is not important.

Potatoes need at least 3 months of warm, frost-free conditions to grow. In cool areas, it’s important to time the planting of Potatoes so that the foliage emerges after the last chance of frost.

Choose a spot with loose, well-drained soil that receives at least 6 hours of sunshine a day.

Prior to planting seed Potatoes, improve and enrich the soil with Yates Dynamic Lifter Soil Improver & Plant Fertiliser.

Dig holes or a trench 10-15cm deep. Plant seed Potatoes with eyes or shoots facing up and space 35-40 cm apart. Backfill with soil and water in well. If planting several rows, ensure you leave at least 50cm between each row.

Over the coming weeks, shoots will appear.

For indeterminate Potato varieties, cover the shoots with soil from either side of the hole or trench and water well. Alternatively, stems can be covered with layers of sugarcane mulch, lucerne or pea straw. Continue to cover new shoots with soil or mulch as they emerge. This prevents light from reaching the tubers, which stops them from turning green, as well as encouraging more Potatoes to develop up the stem.

For determinate Potato varieties, ongoing coverage of the stems is not required, and the tubers will develop in one layer.

Feed plants fortnightly with Yates Thrive All Purpose Soluble Fertiliser. Continue to mound soil or cover with mulch as the plant grows, watering well each time to keep the soil just moist. Repeat until the mound reaches approximately 60 cm tall.

Potatoes should be ready to harvest when the plants begin to flower or the foliage has yellowed and started to die back. To check whether the Potatoes are ready, you can gently feel under the soil with your hands (called ‘bandicooting’). If the Potatoes are still small (often called chat Potatoes), you can pick some or leave them for a few more weeks to develop.

If you’re short on space, you can grow Potatoes in a large pot (at least 50 cm wide and 50 cm deep) or a special Potato bag. It’s important that the pot or bag has good drainage holes. Place the pot in a position that receives at least 6 hours of sunshine a day.

Choose a good quality potting mix like Yates Premium Potting Mix with Dynamic Lifter. Half-fill the pot with potting mix and place a seed Potato on the surface and cover with 10-15 cm of mix. In a 50 cm diameter pot you can grow three Potato plants, spaced out evenly in the pot.

Over the coming weeks, shoots will appear.

For indeterminate varieties of Potatoes, cover the shoots with fresh potting mix and water well. Alternatively, stems can be covered with layers of sugarcane mulch, lucerne or pea straw. Continue to cover new shoots with potting mix or mulch as they emerge. This prevents light from reaching the tubers, which stops them from turning green, as well as encouraging more Potatoes to develop up the stem.

For determinate varieties of Potatoes, ongoing coverage of the stems is not required, and the tubers will develop in one layer.

Feed plants fortnightly with Yates Thrive All Purpose Soluble Fertiliser. Continue to mound potting mix or cover with mulch as the plant grows, watering well each time to keep the potting mix just moist. Repeat until the potting mix or mulch reaches the top of the pot.

Potatoes should be ready to harvest when the plants begin to flower or the foliage has yellowed and has started to die back. To check whether the Potatoes are ready, you can gently feel under the potting mix with your hands (called ‘bandicooting’). If the Potatoes are still small (often called chat Potatoes), you can carefully pick some or leave them for a few more weeks to develop. If the Potatoes are well-sized, you can also tip over the entire pot to reveal and harvest all the tubers at once.

Seed Potatoes aren’t traditional ‘seeds’, but rather small to medium-sized Potatoes that are grown specially for planting. Seed Potatoes from garden centres and online suppliers are certified disease-free. This is important as some serious Potato diseases, such as Blight, can be transmitted on Potato tubers and infect your soil and other susceptible plants for many years. If you start your Potatoes from supermarket Potatoes, these could carry a disease, and which is why you will usually see on bags of supermarket Potatoes a warning that says ‘not for planting’. You could be fortunate not to get a diseased Potato and you’ll get a great crop, but you can’t be sure, hence the advice to plant certified seed Potatoes.

Growing potatoes from store or supermarket potatoes is not recommended. They may carry plant diseases, which could infect your soil and other susceptible plants for many years. It is why you will usually see on bags of supermarket Potatoes a warning that says ‘not for planting’. It is best to start Potato plants from seed Potatoes, which are small to medium-sized Potatoes that are grown specially for planting. Seed Potatoes from garden centres and online suppliers are certified to be disease free.

The process of ‘chitting’ involves allowing the seed Potatoes to start developing small shoots prior to planting. Potatoes will still grow if you don’t chit them, but it does help give them a head start. And particularly in cool areas, it allows you to start the growing process indoors during mid to late winter, while you wait for the weather to warm up.

To chit Potatoes, put the seed Potatoes in a single layer in an open egg carton, with an ‘eye’ (spot on the Potato where a shoot will develop) facing up. Large seed Potatoes can be cut into medium-sized chunks, as long as they have at least one eye. Place the egg carton in a dry, brightly lit spot, out of direct sunlight. After 2-4 weeks, shoots will start to grow. When the shoots are 2-3 cm long, the seed Potatoes are ready for planting.

Potatoes are commonly planted in late winter and spring and grow during spring and summer. If you live in a frosty area, wait until after the last frost to plant Potatoes. In warm frost-free areas, Potatoes can also be planted in autumn.

It takes three to four months for Potatoes to be ready to harvest. Look for the plants beginning to flower or the foliage yellowing and dying back. To check whether the Potatoes are ready, you can gently feel under the soil or potting mix with your hands (called ‘bandicooting’). If the Potatoes are still small, you can carefully pick some or leave them for a few more weeks to develop. If the Potatoes are well-sized, you can pick what you need or store excess in a dry, dark spot inside. You don’t need to harvest all your Potatoes at once. Choose the largest ones first and leave the remainder in the soil or pot until they’re needed.

There are various pests and diseases that can be present in the soil after growing Potatoes. This is why practicing crop rotation is important. Try not to grow anything from the Potato family (Solanaceae) in the same garden bed for at least three to four years. Plants in the Potato family include Tomatoes, Eggplant, Capsicum and Chilli.

After Potatoes you could plant a green manure crop, leafy vegetables like Lettuce, Silverbeet and Spinach, Brassica vegetables like Broccoli and Cauliflower, or a vegetable from the Onion family like Onions, Garlic and Spring Onions.

Yes, green Potatoes can be poisonous. Potatoes will turn green if they’re exposed to light. The green colour can indicate the presence of a toxin called solanine, and if ingested can lead to symptoms including diarrhea, fever and nausea. Green potatoes can also be bitter. So, to prevent Potatoes from turning green, it’s important to mound the soil while the plants are growing and store mature Potatoes in the dark.

A complete and balanced fertiliser is best for Potatoes and will encourage healthy green leaf growth as well as lots of tubers. Yates Thrive All Purpose Soluble Fertiliser is ideal for fertilising Potatoes. Apply fortnightly up until harvest to keep Potato plants well-fed.

Yes, you can reuse the potting mix from potted Potatoes. It is best to use that potting mix to grow plants that are not related to Potatoes, for example, Lettuce, Silverbeet, Spinach and Spring Onions.

Before planting new plants, improve and enrich the old potting mix by adding a rich organic fertiliser like Yates Dynamic Lifter Soil Improver & Plant Fertiliser.

It is common for people to grow Potatoes in old car tyres, stacking more tyres on top of each other as the plants grow. However, tyres contain a range of chemicals and it is unclear whether they may leach out of the tyre and be absorbed by plants. So, we recommend not growing edible plants, like Potatoes, in car tyres.

Aphids and Whiteflies are small sap-sucking insects that can cause Potato plant foliage to yellow or distort. These insects can also transmit damaging plant viruses.

As soon as Aphids or Whiteflies are noticed, spray plants thoroughly every 5-7 days with Yates Nature's Way Vegie & Herb Spray. It's important to spray both sides of the foliage, as Aphids and Whiteflies commonly hide on the undersides of leaves.

Various leaf-chewing pests eat big holes in Potato leaves including Caterpillars, Beetles, Weevils, Snails and Slugs.

There are several types of Caterpillars that attack Potatoes, including Potato Moth Caterpillars which chew through leaves and stems and also into Potato tubers. As soon as Caterpillars (or their damage and droppings) are noticed, spray plants every 5-7 days with Yates Nature's Way Caterpillar Killer - Dipel.

Various Weevils and Beetles, including the 28-Spotted Ladybird, attack Potato plants.

The 28-Spotted Ladybirds are orange Beetles (with 28 black spots). Unlike beneficial Ladybirds which we encourage into our gardens, the 28-Spotted Ladybird chew plant leaves. Both adults and larvae of this species rapidly defoliate Potato leaves.

To help keep Weevils and Beetles under control, simply pick pests off the plant as you see them, then squish them underfoot.

As soon as Snails and Slugs are noticed, sprinkle Yates Snails & Slug Bait around plants.

There are various nematodes that attack the roots and tubers of Potatoes such as the Root-Knot Nematode, Pale Potato Cyst Nematode, and Golden Potato Cyst Nematode. These worm-like microscopic pests infect the roots and tubers of Potatoes. Symptoms may appear as cysts, nodules, lumps or bumps on roots and tubers, as well as brown spots inside tubers.

There is no chemical control for nematodes. The best thing to do is rotate crops (see What Can I Plant After Potatoes), and use garden soil and fertilisers from reputable suppliers.

Early Blight is a slow-spreading disease caused by the fungus Alternaria spp. Symptoms are first seen in the old leaves, generally near the base of the plant. Leaves develop spots that are tan-brown in concentric rings, like a ripple. Edges of spots are yellow. As the disease worsens, the spots get bigger, and the leaf becomes almost completely yellow and comes together. The disease is favoured in warm and wet weather.

Late Blight is caused by a fungus-like (oomycetes) disease known as Phytophthora sp. Symptoms start on young leaves and then spreads inwards to older leaves. Small green spots develop into large brown to purple-black water-soaked sections. In high humidity, and cool and wet weather, mould may be seen on the edge and underside of leaves. Leaves eventually shrivel up and die.

Blight diseases can cause tubers to develop black sunken areas on the surface that eventually rots the entire tuber. To help reduce Blight diseases, start growing Potatoes from certified disease-free seed Potatoes and don't plant in the same spot each year. Spray plants with Yates Mancozeb Plus Garden Fungicide & Miticide every 7-10 days.

There are many viral diseases that affect Potatoes. These cause the plant to look deformed and stunted, and may have a yellow or mottled pattern that is seen across most of the leaf and leaves.

There is no chemical control for viruses. The best thing to do is always start with disease-free seed Potatoes, practice crop rotation, control sap-sucking insect pests like Aphids and Whiteflies (which can carry and transmit viruses) and always get soil and fertiliser from reputable suppliers.