How To: Grow Potatoes

Potatoes are perhaps the nation’s favourite vegetable. They are massively versatile and a staple food in many meals as they can be mashed, boiled, baked or turned into chips. There are two types of potatoes; the early crop which are ‘new’ potatoes and then the main crop varieties which are larger and produce a bigger harvest.

How To: Grow Potatoes

When to sow potatoes

Potatoes are grown from specially prepared “seed” potatoes which are also known as tubers. These seed potatoes can be purchased from January onwards and should be kept in egg cartons for several weeks to allow them to sprout. 

If you would like early potatoes they can be planted from mid-March, while the second batch of earlies should ideally be planted a couple of weeks after. For maincrop potatoes, they are usually planted in April and need to stay in the ground for much longer. In warmer parts of the country, it is possible to plant a second round of maincrops in late summer which will yield a harvest in time for Christmas.

How to plant potatoes

Whilst potatoes are usually grown in the ground, it is possible for them to be grown in large containers. New potatoes can even be grown in baskets or windowsill containers. 

Using certified disease-resistant seed potatoes, cut any large ones into golf ball-sized pieces one to two days before planting. Make sure each section has at least 1-2 ‘eyes’, and any potatoes smaller than a chicken’s egg can be planted whole. 

Ideally, the ground will have been prepared the previous autumn or winter, with garden compost or well-rotted manure added into the soil. 

Traditionally, potatoes are planted in narrow trenches around 12cm (5”) deep. The tubers are spaced out by 30cm (12”) for the earlies and 37cm (15”) for the maincrops. The rows should be 60cm (24”) apart for the earlies and 75cm (30”) apart for the main crops. You can also apply a general-purpose fertiliser at this stage.

How To: Grow Potatoes

How to care for your potatoes

Potato plants require a sunny place in your garden where they can avoid any late frosts in April or May. During the warmer, drier periods it’s important to water regularly and keep the soil free from weeds. 

As the potato plants grow use a spade or hoe to cover the shoots with soil to keep the tubers covered and dark. This will prevent them from becoming green, inedible and toxic. This process is called ‘earthing up or hilling’. Just remember to leave a few centimetres of the plant showing at the top – but as they grow they will need earthing up again. 

In terms of pests and disease, slugs can cause problems, especially if you are growing them under black plastic. Potato blight is a fungal disease which turns the foliage yellow and dark patches and causes the tubers to rot. If you are new to growing potatoes it’s recommended to grow blight-resistant varieties to avoid this problem. You can also cut down an infected plant at the first sign of infection. 

It’s advisable never to grow potatoes in the same patch of soil year after year as this leads to a build-up of pests and diseases, including eelworm which causes stunted growth and poor crops.

When to harvest potatoes

Harvesting potatoes should be done on dry days and dug up gently so as to not cut or bruise the skin. While they can tolerate a light frost it is best to dig them up before any hard frosts as this may damage them.  New potatoes can be harvested 2 to 3 weeks after the plants stop flowering and should be eaten within a few days, as they do not keep long. First earlies are harvested in June or July, whereas second earlies are harvested in July and August.  Mature potatoes can be harvested 2 to 3 weeks after the foliage has died back (around August to October), and can be kept for many months in a cool dark place after being cured. 

Mature potatoes can be stored for several months in a cool, frost-free place such as a cellar or pantry. All light must be excluded so they do not turn green and poisonous; hessian or thick brown paper sacks with a few holes are ideal. Even after being harvested they still require oxygen and give off carbon dioxide, and never store them near apples as this will cause them to spoil. 

Seed potatoes can be purchased from garden centres and nurseries; speak with a member of our team at Holt garden Centre if you would like further advice about how to grow potatoes at home.

Read More

  • White Potted Orchid

    How To: Look After Orchids

    Find out more about Orchids and how to help them thrive indoors.

  • How To: Make Compost at Home

    How To: Make Compost at Home

    Making compost at home is an environmentally friendly way to create nutrient-rich soil for your plants utilising kitchen and garden waste.

  • Bumble bee on Pink Rose

    How To: Save Bees With a Bee Garden

    Bees are a vital part of our ecosystem. Let’s find out how we can protect these important pollinators. 

  • How To: Attract Birds To Your Garden