At a glance
Potatoes are the most widely grown vegetable crop in the UK, and once you have dug your first plant and held a cluster of fresh tubers in your hand you will understand why. The flavour of a homegrown new potato eaten within an hour of lifting is simply not replicable by anything you can buy – the sugars begin converting to starch the moment the tuber is separated from the plant, which means the shops are always selling you a degraded version of what you could be growing yourself. Beyond taste, potatoes are generous, forgiving and remarkably versatile as a crop. They grow on almost any soil type, they tolerate reasonable neglect, and they give back far more than you put in.
This is a complete guide – covering every type, every key technique and every significant problem in one place. It absorbs what would otherwise be separate articles on new potatoes, maincrop potatoes, first and second earlies, chitting, earthing up, harvesting, the no-dig method, blight management and variety selection for both gardens and allotments. Whether you are planting your first row or trying to understand why your maincrops keep getting blight, everything you need is here.
First earlies, second earlies and maincrops explained
The most important thing to understand about growing potatoes is that the three main types are not interchangeable – they operate on different timescales, suit different purposes and face different risks. Choosing the right type for what you actually want from a crop will do more to determine your success than any other single decision.
First earlies are what most people call new potatoes. They are planted earliest, harvested earliest (typically June and July), produce smaller tubers and cannot be stored – they are eaten fresh within days of lifting. Their key advantage beyond flavour is that they are out of the ground before potato blight becomes serious in most UK summers, and they need less space per plant than maincrops. This makes them ideal for smaller plots and for anyone growing on an allotment where blight is a recurring problem. Second earlies follow a few weeks behind first earlies in planting and harvest timing, producing slightly larger tubers suitable for salads, boiling and general kitchen use. They share many of the advantages of first earlies in terms of blight avoidance and are the type many experienced growers regard as the best compromise between earliness, size and flavour. Maincrops are the big storage potatoes – the bakers, the chippers, the roasters. They are in the ground the longest (up to 20 weeks), produce the heaviest yields and store well through winter. They are also the type most at risk from blight and from slug damage in the second half of summer.
All timings above are for average UK mainland conditions. In Scotland, northern England, upland areas and exposed sites, delay all planting by two to three weeks. In the mildest parts of the south-west, first earlies can sometimes go in as early as early March in a sheltered spot. The more useful guide than calendar dates is soil temperature – potatoes should not be planted until the soil is consistently above 7°C. Cold wet soil at the right date will stall them for weeks and risk rotting the tubers before they establish. On an allotment, the combination that most growers settle on is one or two rows of first earlies to eat fresh through June and July, a row of second earlies extending into August, and a row or two of maincrops to store through winter. This gives a rolling harvest over five months from one season’s planting.
Best varieties for UK gardens and allotments
Variety choice is one of the most enjoyable decisions in growing potatoes because there are hundreds to choose from, and many of the best ones are completely unavailable in shops. Always buy certified seed potatoes rather than using old tubers from the kitchen – certified stock is guaranteed free from viruses and the soil-borne diseases that can contaminate your ground for years. Popular varieties sell out early: seed potatoes go on sale from late December and first earlies like Rocket can be difficult to find by February. Buy early and store in a cool, dark place until you are ready to chit.
On an allotment where maximising yield and avoiding disease losses matter most, the combination of one fast first early (Rocket), one reliable second early (Charlotte or Kestrel) and either a proven maincrop (Maris Piper) or a blight-resistant variety (Sarpo Mira) covers all bases and gives a harvest running from June through to October from a single season’s planting.
How to chit seed potatoes
Chitting means encouraging seed potatoes to produce short, sturdy sprouts before planting. You stand them in egg boxes or seed trays with the rose end – the end with the most small indentations or eyes – pointing upward, and leave them somewhere cool, bright and frost-free for four to six weeks until the sprouts are about 2-3cm long. A spare bedroom windowsill, an unheated but light porch or a frost-free garage all work well. Warmth produces long, pale, spindly shoots that snap off at planting; darkness produces the same problem. You want short, dark green or purple, firm sprouts – these are the ones that establish quickly once in the ground.
Whether chitting is worth doing depends on the type. For first earlies, it genuinely brings the harvest forward by two to three weeks compared to unchitted tubers – the difference between new potatoes in early June or late June is meaningful. For first earlies, limit each tuber to two or three of the strongest sprouts and rub off any additional ones; too many shoots splits the plant’s energy across too many small tubers. For second earlies, chitting offers some benefit to harvest timing and is generally worth doing, but shoot thinning is not necessary. For maincrops, chitting makes very little practical difference to final yield because they are in the ground for up to five months regardless. Many growers still chit maincrops as a way of checking the tubers are healthy and viable before planting – if a tuber sits in the egg box for six weeks and fails to produce any sprouts, it is best discarded. Start chitting first and second earlies from late January in mild areas and up to early March in Scotland or exposed upland plots.
Soil, site and how to plant
Potatoes want an open, sunny site with at least six hours of direct sunlight daily. They tolerate most soil types but perform best in fertile, well-drained ground with a pH of around 5.5-6.5. Do not lime the soil before growing potatoes – raising the pH encourages common scab, a disease that creates rough patches on tuber skins. Add well-rotted manure or garden compost the previous autumn if possible; fresh manure directly before planting also encourages scab and should be avoided. On heavy clay, working in grit and organic matter improves drainage and reduces the risk of tubers rotting in the ground.
Rotation is non-negotiable. Never grow potatoes – or any other Solanaceae family member including tomatoes – on the same ground within a three-year period. Soil-borne diseases, blight spores and eelworm populations all build up when potatoes are grown repeatedly in the same spot, and these problems become progressively harder to manage. Waiting three years between crops is what most growers aim for; on a small allotment or raised bed, growing in fresh compost in containers or bags each year is the practical alternative that bypasses the soil-borne disease problem entirely.
To plant, draw out a trench 12-15cm deep with a draw hoe or spade. Place seed potatoes along the base with the shoots pointing upward. Handle chitted tubers with care – the shoots are brittle and snap easily. Cover the trench back to ground level with soil and water in well if the ground is dry. Do not mound soil up at planting stage; that comes later when you earth up. On heavy clay, add a layer of garden compost to the base of the trench before planting to improve drainage around the tubers. Soil temperature should be at or above 7°C – planting into cold wet soil in an eager late February on an exposed allotment will see tubers sit dormant for weeks and potentially rot before they establish.
Never plant supermarket potatoes. They may have been treated with sprout suppressants, carry viruses that spread through your soil, and often produce unreliable crops. Certified seed potatoes from a reputable supplier are guaranteed disease-free and specifically selected for the characteristics listed on the label. The difference in germination reliability alone is worth it.
The no-dig method
Traditional potato growing involves digging trenches, planting, earthing up by drawing soil from between rows, and digging the crop out at harvest. The no-dig method replaces all of that with compost or mulch applied on top of undisturbed soil, offering advantages in terms of labour, weed suppression, soil structure and – in some trials – yield. It is particularly relevant for allotment growers working heavy clay soil who want to avoid the physical effort of trenching, or those who have invested time in building good no-dig beds and do not want to undermine the soil structure they have created.
The no-dig method works as follows. Prepare the bed by applying a layer of well-rotted compost or aged manure 5-10cm deep over the surface of the undisturbed soil. Use a trowel to make a small hole or push-slit 5-7cm deep for each tuber, place it sprout-side up, and close the compost back over it. As plants emerge and grow, add more compost around the stems rather than drawing up soil – this replaces earthing up. You are building the loose, dark growing medium upward rather than mounding soil from the sides. At harvest, grasp the stems at the base and pull gently upward. On well-prepared no-dig ground most of the tubers come up with the plant without any digging at all, which eliminates fork damage and makes a clean, quick harvest. Any tubers left behind are easy to spot and remove by hand. The compost that has been built up over the season improves the soil’s organic matter content as it breaks down into the ground below, adding long-term fertility to the plot.
Earthing up, watering and feeding
Earthing up is the regular task through spring and early summer of drawing soil up around the growing stems. It has two purposes: preventing developing tubers from exposure to daylight, which turns them green and produces solanine – a naturally occurring toxin that makes green potatoes dangerous to eat – and giving tubers more depth of loose, workable soil to form in. You start when shoots are around 15-20cm tall, drawing soil from between rows up around the stem bases with a draw hoe or spade, burying the stems to roughly halfway. Repeat every two to three weeks as plants grow, aiming for a final ridge height of 20-30cm. Stop earthing up once the plants come into full flower – by that point the tubers are well covered and the plants do not need further soil added.
Watering becomes critical from the moment plants come into flower, which is when tubers begin to form and swell actively. Inconsistent watering at this stage – dry periods followed by heavy rain or irrigation – causes tubers to grow unevenly, cracking the skin or producing hollow hearts. Aim for consistent, steady moisture rather than occasional deep soakings followed by drought. Water at the base of plants rather than over the foliage; wetting the leaves in warm humid conditions increases blight risk significantly. In dry summers, deep watering twice a week is about right for established plants. Feeding is only necessary on genuinely poor ground – on average garden soil or allotment ground with compost dug in, potatoes are moderate feeders and a balanced granular fertiliser worked in at planting is sufficient. Avoid high-nitrogen feeds once plants are in active growth, as nitrogen promotes leafy top growth at the expense of tubers.
Harvesting new potatoes and maincrops
The harvest approach differs significantly between early potatoes and maincrops, and getting it right makes a real difference to eating quality and keeping ability.
First earlies are ready when the plants come into flower – typically 10-12 weeks after planting. Scrape back a little soil at the edge of a ridge to check tuber size rather than waiting for a clear visual signal from the plant. If the tubers are the size of an egg or larger, they are ready. First and second earlies do not need to be lifted all at once – you can dig one or two plants at a time as needed and leave the rest in the ground to continue swelling slightly, as long as you use them within a week or two. Eat new potatoes the same day they come out of the ground if at all possible – the sugars begin converting to starch almost immediately after lifting, and the flavour deteriorates noticeably even within 24 hours of harvest.
Maincrops are ready once the foliage (called the haulm) has yellowed naturally and died back completely, usually from late August onwards. For any maincrop variety you intend to store through winter, cut the haulm down to ground level two weeks before lifting. This hardens and thickens the skins during that two-week period, which dramatically improves keeping quality. Lift on a dry day using a flat-tined garden fork, pushing it into the ground well away from the plant to avoid piercing tubers. Lay the lifted potatoes on the soil surface for a few hours in dry sunny weather to let the skins firm up before bringing them in. Any tuber you have accidentally speared or that shows damage should be set aside for immediate use – damaged potatoes rot quickly and contaminate anything stored alongside them.
Never eat green potatoes. Exposure to daylight causes potato tubers to produce solanine, a naturally occurring toxin. Any tuber that has turned green on the skin or internally must be discarded entirely – cutting around the green area is not sufficient. Consistent earthing up throughout the season is the best prevention.
Storing your crop through winter
First earlies and most second earlies do not store well and should be eaten fresh within days of lifting. Maincrops, once properly hardened by cutting the haulm and leaving in the ground for two weeks before lifting, will keep for four to six months under the right conditions. The ideal storage environment is cool (4-7°C), completely dark and well-ventilated. A garage, shed, cellar, outbuilding or unheated spare room is far better than anywhere in a centrally heated house where warmth will cause rapid sprouting and deterioration.
Store different varieties in separate labelled hessian or paper sacks – keeping qualities vary between varieties and mixing them makes it impossible to use the shortest-keeping ones first. Avoid storing potatoes near apples, which produce ethylene gas that can cause premature sprouting. Under good conditions, maincrops like Maris Piper and Desiree will keep reliably from October through to February or March. Late maincrops and blight-resistant varieties like Sarpo Mira generally store even longer.
Potato blight – identification and control
Potato blight (Phytophthora infestans) is the most serious disease affecting UK potato growers, particularly those growing maincrops in wet summers. It is the same pathogen responsible for the Irish potato famine of the 1840s and it remains widespread in the UK, with spores circulating in the air across the country once conditions become favourable – typically warm, humid weather in July and August. Once established in a crop it can destroy all the foliage within days and spread down into the tubers, rendering the entire crop inedible. Early identification and fast response are the only effective tools available to home growers.
The signs of blight are distinctive: dark brown patches appear on leaves, usually starting at the tips and edges, with a pale yellow or green halo at the margin. In humid conditions, a white fungal growth is visible on the undersides of affected leaves. Stems turn dark brown or black at the base. If the disease reaches the tubers, they develop brown, dry or wet rot inside that progresses even in storage. The conditions that trigger blight are well-documented – warm nights above 10°C combined with relative humidity above 75% for two or more consecutive days are the classic blight weather conditions. In a wet UK summer this can occur from late June onwards, though July and August are the most common months.
There is no chemical treatment available to home growers that effectively controls blight once established – all previous fungicides permitted for home use have been withdrawn. The only meaningful long-term strategies are variety selection (Sarpo varieties have genuine resistance, not just tolerance), cultural controls (good spacing, watering at the base, fast action on first symptoms), and rotation. First and second early varieties largely sidestep the blight problem because they are out of the ground before the peak blight window in most UK years.
Other common problems
Beyond blight, several other problems commonly affect UK potato crops. Most are manageable with the right response.
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