Seed tubers of potatoes should be planted around late March for first earlies, early to mid-April for second earlies and mid- to late April for maincrops. This varies slightly depending on where you are in the country.
The traditional way is to dig a narrow trench 12.5cm (5in) deep. This can be lined with compost or even grass clippings for a better crop. The seed tubers are spaced 30cm (12in) apart for earlies and 37.5cm (15in) for maincrop varieties in rows 24in (60cm) apart for earlies and 75cm (30in) apart for maincrop. Sprinkle slug pellets or other slug deterrents between the tubers as keel slugs can be a problem.
Potatoes need a sunny site away from frost pockets.
It's important to keep light away from the developing new potatoes as light turns them green and green potatoes are poisonous.
There are numerous ways of growing potatoes.
It's vital with earlies and a good idea with maincrops to chit the seed tubers first before planting; this means allowing them to produce sturdy shoots. Buy your seed potatoes in late January/February and stand them rose end up (the rose end has the most eyes) in egg boxes or similar in a light, frost-free place. The tubers are ready to plant when the shoots are about 2.5cm (1in) long.
Once planted, when the stems are about 23cm (9in) high, start earthing up by carefully drawing soil up to the stems and covering to produce a flat-topped ridge about 15cm (6in) high. This can be done little and often or in one go.
Newly emerging foliage is susceptible to frost damage. You can prevent this by earthing up the soil around the shoots or by covering them with fleece.
The other method is to grow the potatoes under black polythene. The tubers are planted through the black polythene. The advantage of this method is that there is no need to earth up and the new potatoes form just below soil level which means there's no digging to harvest them.
It's also possible to grow them in large containers - or even black bin liners. 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.
Keep crops well watered in dry weather; the vital time is once the tubers start to form. A liquid feed of a balanced general fertiliser every fortnight can help increase yields.
First early potatoes should be ready to lift in June and July, second earlies in July and August, maincrops from late August through October.
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 it and remove it. Leave for 10 days before harvesting the tubers, leaving them to dry for a few hours before storing.
‘Accent’ AGM: A first early with creamy waxy flesh and good scab resistance. It’s a very tasty new potato.
‘Charlotte’ AGM: This is a salad potato, with yellow-skinned waxy tubers. Treat as an early potato.
‘Desiree’: A firm favourite with rosy skin and pale yellow flesh. This is a versatile maincrop potato.
‘Picasso’ AGM: A heavy-cropping maincrop potato with creamy skin and pink eyes. It has good disease resistance to scab.
Potato blight: This is a common disease in wet, warm summers. The initial symptoms are a rapidly spreading brown watery rot, affecting leaves, and stems. Tubers can be affected too, and have a reddish-brown decay below the skin, firm at first but soon developing into a soft rot.
Remedy: Unfortunately once blight starts, it is very difficult to stop. You can remove blight-affected leaves, but removing too many leaves will damage the plant’s ability to grow. Earthing up potatoes provides some protection to tubers. There is no chemical control to stop blight, but you can spray with a protectant spray in June if it looks like it will be a wet one.
More information on potato blight
Potato blackleg: Potato blackleg is a common bacterial disease which causes black rotting at the stem base. Initial infections cause stunted growth and yellowing stems. If tubers form, the flesh may be grey or brown and rotten.
Remedy: Remove and destroy infected plants. Rotate crops. Buy resistant varieties such as 'Charlotte', 'Pixie' and 'Saxon'.
More information on potato blackleg
Potato scab: This disease causes raised scab-like lesions on the potato surface. It does not affect the taste of the potato, and is easily removed on peeling.
Remedy: There is no control for scab, and you usually won’t know anything is wrong until harvest time. Scab can be worse in dry weather, so keep potatoes well watered. Don’t store any potatoes with scab.
More advice on potato scab
Potato rot: Potato tuber rots are a frequent cause of losses prior to, or after, lifting. Significant problems often follow a wet growing season, particularly if the tubers are then lifted from wet soil.
Remedy: Use good quality, resistant certified seed tubers when planting and harvest when the soil is neither wet nor very hard and dry. Store in cool, dry conditions.
More information on potato rot
Slugs: Slugs are a nuisance, as not only can they eat holes in the leaves, they also eat and burrow into the tubers. You’ll see the tell-tale slime trail of slugs on the soil around your crop, as well as on the leaves.
Remedy: There are many ways to control slugs, including beer traps, sawdust or eggshell barriers and copper tape. Experiment, as you may find some more successful than others. Slug pellets of powders based on aluminium sulphate or ferric phosphate are less toxic on other wildlife.
More information on slugs