How to Grow Potatoes: A Detailed Guide

Potatoes are one of our diet staple foods and growing potatoes by yourself can save a lot of money. The UK loves chips, roast potatoes and mash, and healthier options using sweet potatoes too. Potatoes are easy to grow and are quite resilient.  

Here at Allotment Online we will guide you on growing potatoes indoors from start to finish. Learn all the tips and tricks on the best way to grow potatoes in our detailed guide.

Growing Potatoes: When and Where

Potatoes come in differing colours, shapes and sizes. They are classified into early crop, second earlies and main crop as per the length of their growing times.

There are many varieties within the 'early crop' and 'main crop' types, as well as getting down to first and second earlies. Your planting may depend on location and weather, but generally first earlies (new potatoes) are planted out in late March, second earlies go in early to mid-April and your main crop is towards the end of April. Be cautious about late frosts that can damage young plants. 

How Do You Plant Potatoes

Before your planting begins, there is some preparation you need to be working on. It is a good idea to chit your early potatoes to give them a head start. Chitting potatoes means to allow the potatoes to grow shoots to get a bigger crop. We talk about this in more detail on our page for chitting potatoes. 

Ensure you properly check the seed potatoes before buying. Check for firmness and avoid ones with very long roots or with signs of mould.

You will need to prepare your soil beds too by giving them a digging over with a good mix of compost or well-rotted manure, that works as a great fertiliser for potatoes. 

How to Grow Potatoes at Home

You don’t need a huge garden, as potatoes can also be grown in large containers and pots. Add good quality soil and compost and plant one or two potato seeds in approximately 6 inches and then when the plant starts to grow above the soil, keep covering with soil as they grow until you are near the top of the container. The foliage will grow, and your potato plants will produce flowers. Once the foliage starts to die off, this is an indication that your new potatoes are ready. You can always have a rummage and see what you find! 

For planting out your potato tubers, you will need to dig a trench of approximately 5 inches deep in rows about a foot apart with the rows being approximately 2 feet apart for earlies and double these measurements for main crops. As the plants grow, you will need to 'earth up', which means to mound up the earth to protect your potato plants against frosts, and light, which can turn your growing potatoes green and poisonous.

Some growers use black polythene with slits to plant and grow to avoid the need for earthing up and digging. Your crops will require good watering during dry spells. A nitrogen-rich soil or fertiliser for your potatoes is beneficial, particularly for main crop varieties once the tubers have formed. 

When to Pick Potatoes

Depending on when you plant and harvest your potatoes, there are three main types, namely first earlies, second earlies and main crop potatoes. 

Your early crops should be ready during June and July once the flowers have opened and dropped, carefully removing the plant and digging for your potatoes. Harvesting times will depend on your planting times. Earlies do not last as long as the main crop in storage and should be used sooner rather than later; so it is best to eat them fresh. 

When you have harvested your earlies, allow them to dry out and store them in a cool place in a Hessian, brown paper sack/s or cardboard box/es. Inspect your crop for any damage to ensure that you do not contaminate the remaining crop with infected potatoes. Some problems can be cut or scrubbed away and still be used such as bruising, whilst others, such as blight, rot or scab, it is much safer to discard. If growing potatoes under black plastic, slugs can cause problems to your crop.

Second earlies will be ready around July and August and main crop potatoes from late August through until October. dependent on your planting times. Unlike earlier, the main crop can last a lot longer in storage, just follow the same guidelines as for the early crops. 

Main crop potatoes are ready when the plants begin to yellow and die. Suitable for baking, roasting and mashing, main-crop potatoes take the longest to mature. 

A word of caution: never eat potatoes raw. Raw or green potatoes have a chemical called solanine that develops during light exposure. Having raw potatoes can lead to severe stomach upsets.

Common Problems with Growing Potatoes

Unfortunately, if your crop suffers from any potato-related diseases such as rot, blight, and scab there is very little you can do to salvage your harvest. These infected potatoes should be discarded. You might be able to rescue some healthy ones if you know what to look for. 

Some potatoes produce green fruits as well as flowers. It is important to note that these are NOT edible and are poisonous. These toxic, hard, green balls however are full of seeds and can be harvested for seeds at least 6 weeks after formation. Some will drop and rot and sometimes germination can take place. There is no requirement to remove these green fruits that appear with good weather and pollination, however, that's down to the choice of the grower. 

No matter how thoroughly you think you have cleared your potato growing area, potatoes are renowned for reappearing around the plot, whether in the same bed or elsewhere due to pollination and dispersal. Self-sown plants do not usually produce very good quality potatoes, these tend to be dug up when they are spotted. Also, growing potatoes in the same soil can cause pests like potato eelworms and diseases to build up. Potato eelworms can stunt the growth and result in poor potato crops.