Potatoes are one of the easiest substantial crops to grow at home, and lifting the first young tubers from the soil is a good reward for a little spring preparation. Buy certified seed potatoes, plant them in spring, keep developing tubers covered with soil and water during dry weather. Choose an early variety for tender summer potatoes or a maincrop for a larger harvest that can be stored into winter.
You don't need a full allotment. A few potatoes can be grown in a raised bed or a large container. The crucial thing is understanding the difference between the varieties, especially when to plant them and when they are actually ready to lift.
First earlies, second earlies and maincrops
Potato varieties are generally divided into three groups based on when they mature. First earlies are the quickest, producing small new potatoes in early summer. The RHS says some early varieties can be harvested in as little as 12 weeks after planting.
Second earlies take a little longer and often provide useful salad potatoes through the middle of summer. Maincrops are left in the ground longer, producing bigger tubers that are useful for roasting, baking, mashing and winter storage.
The flavour and texture vary considerably. Some waxy varieties hold their shape beautifully when boiled; floury potatoes are more suitable for certain mashes and roast dishes. Choose the variety for how you will cook it rather than assuming that every potato tastes the same.
For a small garden, an early crop is appealing because the plants occupy the bed for less time. You can harvest them and use the cleared space for another suitable summer vegetable.
Why buy certified seed potatoes?
Seed potatoes are small tubers grown and prepared for planting. Reputable planting stocks are inspected and selected to reduce the risk of introducing important potato diseases.
A potato from the supermarket may sprout, but it isn't the same as certified planting stock. It may not be suitable for your growing season and could carry problems into the soil.
Buy named seed potatoes from a gardening supplier. Check whether they're early or maincrop, and look at the expected planting date. You can order popular varieties in advance when garden centres are stocking them in winter.
Inspect tubers when they arrive. Set aside any that are badly damaged or rotting. A little shrivelling of a stored potato may not automatically make it unusable, but soggy, mouldy tubers aren't a good start.
Should you chit potatoes first?
Chitting means allowing the tubers to produce short shoots before planting. It is particularly useful for first and second earlies when an earlier harvest is the goal.
Stand seed potatoes with their eyes uppermost in an egg box or shallow tray, then put them somewhere bright, cool and frost-free. You want firm, relatively short shoots, not long pale threads produced in a dark cupboard.
The RHS suggests starting chitting in late winter, generally from late January in milder areas to early March in colder ones. It often takes four to six weeks.
Chitting is optional. If you don't have a suitable place, you can plant the seed potatoes without doing it. They will still grow; the harvest may simply arrive a little later. There is generally less advantage to chitting maincrops because their season is already long.
When to plant potatoes in Britain
Planting dates depend on the type and your local weather. The RHS gives these approximate outdoor windows: first earlies around late March; second earlies in early to mid-April; and maincrops from mid-April to early May.
These are guides, not strict deadlines. The soil in a sheltered southern garden warms earlier than soil in an exposed Lancashire allotment. Avoid putting tubers into persistently waterlogged ground simply because a date has arrived.
Potato shoots are vulnerable to frost after emerging. Plan how you will protect early growth if a cold snap returns. Earthing up soil around the developing stems is one way to help shield tender shoots.
Potatoes grown in a greenhouse container can be started earlier if protected from frost, but this is a separate method from ordinary outdoor planting.
Preparing the bed
Choose an open, sunny area with reasonably fertile, well-drained soil. Potatoes appreciate organic matter, so adding well-rotted garden compost or manure to the bed ahead of planting can improve growth and moisture retention.
Remove perennial weeds before digging planting trenches. It is far easier to deal with couch grass roots before the potato foliage grows tall and makes the soil difficult to reach.
Where you have enough space, rotate potatoes with other crops rather than planting them in the same bed every year. This helps reduce the build-up of some soil problems.
For a no-dig plot, suitable well-rotted compost can be spread on the surface, with seed potatoes planted through it according to the method you're using. Keep the developing tubers protected from daylight just as you would in a conventionally dug bed.
Planting potatoes in rows
- Mark the rows. For earlies, the RHS recommends about 60cm between rows; for maincrops, allow roughly 75cm.
- Dig a trench approximately 15cm deep, or individual holes of suitable depth.
- Set the seed potatoes into the base. Place them with their strongest emerging shoots upwards, taking care not to break them.
- Allow room within the row. For earlies, use about 30cm between tubers; for maincrops, about 37cm.
- Cover gently with soil. Avoid stamping directly on the seed potatoes.
- Water appropriately if the ground is dry, then label the row with variety and planting date.
- Watch for emerging shoots and be prepared to earth up before tubers can become exposed to light.
For a small plot, two short rows are often easier to maintain and harvest than one enormous planting. You can also choose different maturity groups to spread out the crop.
What does earthing up mean?
As potato plants grow, new tubers develop underground around their stems. If those tubers are exposed to light, they can turn green and accumulate potentially harmful glycoalkaloids.
Earthing up means drawing loose soil around the stems as they grow, forming a ridge that helps keep the developing potatoes covered. Begin once the shoots are visible and continue as necessary while the plants gain height.
In a container, the equivalent is adding more compost around the lower stems over time. You don't have to bury every leaf or cover the entire plant in one go. Allow sufficient healthy foliage to keep growing.
Earthing up can also provide some protection to low shoots during a late frost. If a hard frost is forecast, check that the tender growth isn't completely exposed.
Growing potatoes in bags or containers
A large growing bag or tub is a practical choice when you don't have room for a bed. Use a robust container with drainage holes and enough volume for a few plants to develop their root systems.
Start with compost in the bottom, set your seed potatoes with appropriate spacing and cover them. As shoots grow, add compost in stages until the container is appropriately filled, leaving useful foliage above the surface.
The RHS school-gardening guidance recommends spacing seed potatoes about 30cm apart in suitable large containers. Don't put a whole packet into one narrow bag and expect a worthwhile harvest.
Water regularly when the compost begins to dry. Bags on sunny paving can dry out quickly, but you must also prevent waterlogging. The aim is a moist, well-aerated root area.
When ready to harvest, you can empty the container carefully onto a suitable surface, collect the potatoes and inspect the crop. This is often easier than searching through a deep bed with a fork.
Watering and feeding potatoes
Established potato plants need water to support their growing foliage and swelling tubers, particularly once flowers begin and during extended dry spells. A thorough watering is more useful than frequent little splashes that never reach the deeper roots.
Container potatoes generally need more frequent checks than bed-grown plants. Lift or feel the bag if practical and check below the top layer of compost before watering.
Where soil was properly prepared with organic matter, additional feeding may not be necessary. In poor soil, a suitable general-purpose fertiliser can be useful, following its label.
Avoid overfeeding simply to produce taller stems. The valuable crop develops underground, and a huge leafy plant isn't proof that you've produced large, healthy potatoes.
When are potatoes ready to harvest?
Earlies can often be lifted while the plants are still green and healthy, when the tubers are large enough for your intended meal. A first early doesn't need to develop into a huge storage potato before it's worth eating.
To check, gently loosen soil at the side of a plant or lift one plant carefully. If the tubers are still tiny, give the remaining plants longer.
Maincrops are usually left longer, until the foliage starts to yellow and die back naturally. Follow the variety's expected maturity and allow the skins to develop if you intend to store them.
Use a fork carefully, digging away from the main stems to avoid spearing or cutting tubers. Damaged potatoes are best used promptly rather than put into long-term storage.
Storing and protecting your harvest
Keep sound maincrop potatoes somewhere cool, dark, dry and ventilated. A breathable paper or hessian sack is more suitable than leaving damp tubers in an airtight plastic bag.
Don't wash potatoes before long storage if doing so will leave them wet. Brush away loose soil when appropriate and allow the skins to dry naturally.
Discard green potatoes rather than cutting off a little green patch and assuming the rest is safe. Exposure to light can raise levels of harmful compounds. Similarly, don't eat the small green, tomato-like fruits that some potato plants produce above ground.
Check stored potatoes occasionally for rot or damage and remove any deteriorating tubers promptly. One spoiled potato can affect its neighbours if left buried in a sack.
Problems to watch for
Brown, rapidly spreading lesions on leaves: Potato blight may be present, particularly in warm, humid weather. Follow current RHS disease advice, and avoid spreading affected material around the garden.
Few tubers after months of growing: Check the variety, planting spacing, sunlight and moisture. Some crops take longer than expected in a cool season.
Green tubers near the surface: The developing potatoes were exposed to light. Earth up earlier next time and discard green tubers from the harvest.
Holes in harvested potatoes: Slugs or wireworms may be responsible. Look at the pattern of damage and improve future pest management.
Shoots blackened after a cold night: Late frost can damage tender foliage. Protect early growth with suitable soil cover or fleece when cold weather returns.
Common questions
Can you grow potatoes from supermarket potatoes?
They may sprout, but certified seed potatoes are the better choice to reduce disease risk and ensure a suitable named variety.
Do potatoes need full sun?
They prefer an open, sunny site for productive growth, though some shade may be tolerated. Deep shade generally produces a poorer crop.
Can potatoes grow in a small garden?
Yes. Early varieties are particularly convenient in large containers or a few short rows, provided roots have enough room and developing tubers remain covered.
Sources and further reading
- Royal Horticultural Society — How to grow potatoes. Chitting, planting dates, spacings, earthing up and harvest.
- Royal Horticultural Society — Growing potatoes in containers. Container planting and harvesting.