How to Grow Potatoes from Seed Potatoes

The great British stand-by, potatoes are hugely versatile and are a staple ingredient of many meals in one form or another. Whether they’re boiled, mashed, chipped, roasted or baked, these vegetables are delicious in many different forms and remain a favourite as a result. Freshly dug and lightly boiled with mint, cooled and eaten with salads or mashed with mustard or horseradish, they just can't be beaten.

If you’re eager to learn how to grow your own potatoes, you can get started with our useful guide below. Here, you’ll find plenty of expert advice on each stage of the growing process and many useful tips to maximise your yield.

After unpacking your seed potatoes, put them in a cool, light, well-ventilated and frost-free place away from direct sunlight. Potatoes can be divided into the following four categories and planted from March to May (after any danger of frosts). Earlies are ‘new’, small potatoes that grow faster and take up less space, while maincrops take longer but produce a bigger harvest with larger tubers. These categories of potatoes can be expected to be ready for harvest around the following periods:

First Early Seed Potatoes – Ready for June to July, or earlier in some sheltered areas.

Second Early Seed Potatoes – Ready for July to August.

Maincrop Seed Potatoes – Ready for August.

Whichever variety you choose, it is worth considering crop rotation before planting, as potatoes are susceptible to a wide range of minor pests and one or two major ones. Potato pests have a limited survival time if they cannot get at the potatoes, so the standard three-crop rotation (potatoes being followed by brassica seeds, followed by other vegetable seeds) will help keep pests at bay.

Potatoes thrive in deep, fertile and well-drained soils. Soil conditions prior to planting are more important than precise planting times. So, prepare the soil well before planting. You should break down any clumps, remove any weeds from the area and add a quality fertiliser (such as Orgro fertiliser) or manure. Potatoes will tolerate many different kinds of soil, though they do best in soil that’s slightly acidic.

If you’re wondering when to sow your seed potatoes, you should do so around late March for first earlies, early to mid-April for second earlies and mid-to-late April for maincrops.

Planting too early in cold, wet soils may cause rotting. So, we recommend you delay planting until the soil is both warm and moist to the touch. In most areas, this is in the March to May period.

There are numerous ways of growing potatoes. The traditional way is to dig a narrow trench 10-15cm/4-6in deep. This can be lined with compost or even grass clippings for a better crop. The seed tubers should be spaced 35cm/14in apart, with rows 45cm/18in apart for early varieties. Maincrop varieties should be spaced 38cm/15 inches apart, with rows 75 cm/30 inches apart.

 You should sprinkle slug pellets or other slug control products between the tubers, as slugs can be a problem.

Chitting Potatoes

The chitting process allows strong green shoots (known as chits) to develop on the seed potato tuber before planting. Although not essential, it is particularly beneficial for earlier cropping potatoes because it gives the potato a quick start, thus cropping slightly earlier. Later cropping potatoes are less likely to need chitting as warmer soil temperatures can make a greater difference.

Start chitting (where necessary) by setting the seed potatoes out, side by side, blunt end uppermost, in single layers in seed trays or a wooden box. Place in a light, cool, well-ventilated spot to encourage the development of stocky shoots 2-2.5cm/¾-1in long, when they will then be ready for planting.

For large potatoes, rub off all but the three strongest shoots before planting. For maximum yields, leave all the shoots in place. Alternate potatoes can be rubbed in the row for the best of both worlds: a high yield and larger, individual tubers.

For further advice on chitting potatoes, take a look at our customer FAQs on chitting potatoes, covering a variety of common queries.

Growing Potatoes from Containers

It is possible to grow potatoes in containers, or even black bin liners, if you have limited space or no open ground to grow them in. Line the bottom 15cm/6in of the container with potting compost, and plant the seed tuber just below this. As the new stems start growing, keep adding compost until the container is full.

For further details on using potato grow sacks, take a look at our guide on how to grow potatoes in a container.

First earlies should be ready to lift in June and July, second earlies in July and August, and maincrops from late August through October.

When harvesting potatoes, it can be difficult to tell when they’re ready for harvest with them being underground. So, the best practice is to gently clear some of the soil to check if they’re of a good size and cover them up again if not yet ready. However, the plants’ foliage growth can otherwise be a good indicator.

With earlies, wait until the flowers open or the buds drop; the tubers are ready to harvest when they are the size of hens' eggs. With maincrops for storage, wait until the foliage turns yellow, then cut and remove it. Leave for 10 days before harvesting the tubers, leaving them to dry for a few hours before storing.

When harvesting, you should remove all tubers, however small, to avoid potential problems when growing crops in the same soil.

Once harvested, be sure to store your potatoes in a cool, dry position, avoiding direct sunlight. For maximising the quality and duration of harvested spuds, we strongly recommend the use of hessian sacks. The hessian blocks direct light whilst allowing any moisture to escape.

Potatoes generally are easy to grow, but can face several problems. These are the following problems that are most common when growing potatoes, with advice on how to prevent or deal with them.

• Slugs - Slugs can pose a problem when growing potatoes, especially so when growing these under black plastic sheets. However, this can be managed effectively with pest control products.
  
  
• Blight - During summer, potatoes can be prone to blight, which is a fungal disease that causes the tubers to rot, turning plant leaves yellow with dark spots. 
• Blight rapidly develops from droplets carried on the wind to form a brown or black circular patch called a lesion. The lesions have a soft, wet appearance and, if formed on leaves, will show white fungal threads on the underside. Once more than a third of the foliage is infected, it is best to remove all foliage off-site because the tubers will have stopped growing anyway.
  
  You can plant disease-resistant seed potatoes or Sarpo seed potatoes to prevent this. Additionally, first and second earlies are popular because they largely avoid blight if they’re harvested early enough.
  
  Crops affected by blight can be eaten if they’re harvested at the first sign of infection. However, you will need to use them quickly, and they won’t be suitable for storage.
• Scab - Scab is a soil-borne bacterial infection. Symptoms of scab may include scab-like raised or slightly sunken rough, corky textured patches on tubers or root surfaces. Unfortunately, the growing conditions needed by potatoes are very close to the conditions in which scab thrives.
  
  Before planting, we recommend that tubers are dipped in a diluted solution of D.T. Brown Plant Tonic No.8. to better protect them against scab. Practising crop rotation may also help prevent infection. If scab is a problem in your soil, we sell several scab-resistant varieties which are more tolerant and resilient to the disease.
• Growing in the same area - If you choose to grow potatoes again the following year, problems can arise in the form of diseases and certain pests. This is why crop rotation is important, which is detailed above under the ‘Before Planting…’ section. For additional information on crop rotation, be sure to read our blog on the topic.

At D.T. Brown, you can find a huge range of quality seed potato varieties to get you started on growing. If you’re eager to grow even more produce, you can find much more gardening advice from our experts on our gardening blog, where you can find many more in-depth growing guides.

If you’d like to find out more about our range of vegetable garden seeds and plants, fruit seeds, and fruit plants, don’t hesitate to get in touch and we’ll happily answer any questions you may have.