Potatoes are one of the most satisfying crops to grow because the harvest stays hidden until you dig it up. You plant a small tuber in spring, keep the leafy growth healthy through the season and eventually uncover potatoes that have developed underground.
The method isn't difficult, but a little planning helps. Buy proper seed potatoes, give the plants enough space, protect them from frost and stop developing tubers from being exposed to sunlight. If you only have a patio, a large container can work just as well for a modest crop.
Start with certified seed potatoes
Seed potatoes are specially prepared tubers intended for planting, not botanical seeds in a packet. Buy certified disease-free seed potatoes from a reputable garden retailer.
The Royal Horticultural Society recommends certified stock because it reduces the risk of introducing certain viruses and diseases into your growing area.
Supermarket eating potatoes can sprout, but their health status, variety and suitability for planting may be uncertain. Starting with proper planting stock is a worthwhile precaution.
Choose the right type of potato
First earlies are grown for relatively early tender new potatoes. Second earlies mature later, and maincrop types generally need a longer season and can produce larger storage potatoes.
Check the variety's growing period, likely size and suitability for your space. A small patio container is often a good home for an early type, while a large maincrop can need more room.
Some varieties resist particular problems better than others. If blight is common in your area, consider varieties with documented resistance and adjust expectations for wet summers.
Know when to plant in Britain
For much of Britain, start with the earliest varieties near the end of March. Plant the next group during April, leaving the later maincrop varieties until the middle of that month or the beginning of May, subject to local frost and soil conditions.
Those are useful broad UK windows, not fixed deadlines for every garden. In colder northern areas and frost-prone spots, conditions may call for later planting or extra protection.
The objective is to avoid damaging new shoots with hard frost and give the growing crop a suitable season. Check local weather and soil condition before committing.
Chit early potatoes if you want
Chitting means encouraging short sprouts before planting. Stand seed potatoes in a tray or egg box with their eyes facing upwards, in a cool bright frost-free place.
The RHS notes that chitting can bring an early harvest forward, particularly for first and second earlies, but it isn't essential. Unchitted potatoes can still grow successfully.
Handle sprouting tubers carefully. Long fragile shoots snap more readily than short sturdy ones, so don't leave them in a dark warm cupboard until they grow spindly.
Prepare the planting site
Potatoes generally perform well in an open sunny position with fertile soil that doesn't remain waterlogged. Remove persistent weeds before planting.
Incorporate suitable organic matter if the soil needs improvement, following RHS guidance. Avoid burying a thick layer of fresh unrotted manure against the seed tubers.
If a patch has grown potatoes or related crops recently, consider crop rotation to help manage soil-borne problems. Small gardens can use containers when there isn't room to rotate beds properly.
Dig trenches or planting holes
For traditional planting, the RHS recommends a trench around 15cm deep. Place the seed potatoes along the bottom with any shoots pointing upward, cover with soil and water.
You can use individual holes instead if you only have a few tubers. Mark the position so you don't accidentally dig through the row while weeding.
Don't plant a bag of seed potatoes all in one small hole. Crowded plants compete for resources and make earthing up difficult.
Leave enough space between plants
The RHS suggests roughly 30cm between early potatoes in rows around 60cm apart. Maincrops need more room, around 37cm between plants in rows 75cm apart.
Exact spacing can vary by variety, soil and growing method. Follow the seed pack when its recommendations differ for a particular cultivar.
Leave space for the crop to spread and for you to access the row. A perfectly straight line is less important than adequate growing room.
Plant potatoes in large pots
Use a container with drainage holes, ideally at least around 30cm wide and deep for a modest early-potato crop. Half-fill it with suitable peat-free compost as the RHS describes.
Place an appropriate number of seed potatoes near the surface, cover with compost and water. Add more compost gradually as shoots develop.
Don't seal drainage holes or leave the container standing permanently in deep water. Roots need moisture but also oxygen.
Earth up the plants as they grow
Earthing up means drawing soil over the lower stems to cover developing tubers. The RHS recommends doing this once shoots reach around 23cm, leaving the upper part of the plant visible.
This protects new potatoes from sunlight, which can make them green and unsuitable to eat. It can also offer some protection to young growth from late frost.
Repeat as necessary without completely burying a mature plant. In containers, add compost in stages until near the rim.
Water sensibly
Potatoes need moisture for healthy growth, especially during tuber development. In dry spells, water the soil thoroughly rather than just wetting the surface.
Container-grown potatoes dry more quickly than those in open ground. Check the compost below the surface and adjust watering to the weather.
Avoid waterlogging. Yellowing leaves can have several causes, including disease, lack of nutrients or excessive moisture, so don't automatically pour on more water when something looks wrong.
Manage frost and weeds
New potato shoots are vulnerable to frost. Use suitable horticultural fleece, a cloche or additional earthing up if a late cold snap threatens.
Weed carefully, especially before the potato canopy has grown large enough to shade the soil. Try not to damage shallow roots or developing tubers with a hoe.
Mulching and sensible spacing can reduce weeding later. Don't bury young plants under a thick mass of unsuitable material.
Watch for blight and pests
Potato blight can spread quickly in damp, mild weather. Learn to recognise suspicious dark lesions on leaves and follow local horticultural advice if infection is suspected.
Slugs, wireworms and other pests may also damage tubers. Check your growing area and use appropriate management methods rather than applying chemical treatments by default.
Healthy certified planting stock, crop rotation and suitable spacing help reduce several problems, but no method guarantees a pest-free harvest.
Know when they're ready
First earlies are typically lifted for small new potatoes, often once plants have flowered or reached their expected maturity period. Maincrops are commonly allowed to develop longer.
Check one plant carefully rather than harvesting the entire row too soon. Tubers should be appropriately sized and their skins suited to how you intend to use them.
After the foliage has died back for mature storage crops, harvest during suitable dry conditions and avoid damaging tubers with your fork.
Keep green potatoes out of the kitchen
Light exposure can make developing tubers green and increase certain natural toxins, particularly glycoalkaloids. Do not eat obviously green or bitter potatoes.
Earthing up prevents sunlight from reaching the tubers. Store harvested potatoes in a cool, dark, suitable place and inspect before cooking.
The RHS explicitly warns that green tubers are poisonous. Do not treat a green surface as merely a cosmetic issue.
An easy first planting
For a first attempt, buy a small pack of certified early seed potatoes, choose a large pot with drainage and follow the RHS container method.
Keep adding compost as the stems grow, water in dry weather and protect the foliage from frost. Harvest a test plant when the variety should be ready.
Growing potatoes is rewarding because you can see the result of simple, consistent care when you finally tip out the container. Start small and learn what works in your own garden.