Growing Potatoes from Planting to Harvest

8 March 2019, written by Benedict Vanheems

Potatoes are one of the most satisfying vegetables to grow. And harvesting time is what makes the potato really special, when those delicious tubers are finally lifted up from the soil like buried nuggets of gold. Garden-grown potatoes are really something else! So if you’ve never tried growing them before, make this the year you do.

Here, then, is our planting to harvest guide to potatoes...

Types of Potato

Before you plant you need to decide what type of potato you need. There are two main types of potato: maincrops and earlies.

Maincrop varieties are usually bulkier and give a bigger harvest, and many can be stored for winter use. Maincrops are typically harvested in late summer or autumn.

Early varieties are ready from early to midsummer and are further divided into first earlies and second earlies. First early varieties are first to crop, while second earlies follow on a few weeks later. Early potatoes tend to be smaller than maincrop types, but they have arguably the best flavor and often have a smoother, waxier texture that makes them perfect in salads. They’re also sublime when served steaming hot, finished with a drizzle of olive oil and a scattering of herbs.

Check variety descriptions for potatoes suited to different uses, whether baked, boiled, sautéed or cut up into wedges – or even a combination of these. Some varieties offer good resistance to common diseases including blight, which can ruin a crop in warm, wet summers. Or grow first earlies, which are usually harvested before the main blight risk.

Preparing and Chitting Potatoes

To plant a crop of potatoes you’ll need to get hold of some seed or sprouting potatoes, also sold as simply ‘tubers’. Large seed potatoes can be cut into smaller pieces to make them go further. Make sure each piece has at least two ‘eyes’ and allow the cut to air dry for a day before planting.

In regions where spring’s arrival is a little slower to arrive it’s worth sprouting or ‘chitting’ your seed potatoes. Do this up to six weeks ahead of planting, to give your crop a head start. Lay them out in a single layer, so the ends with most eyes – that’s the dimples where the shoots will sprout from – face up. Place them into trays or old egg cartons, which hold the potatoes steady. Keep them in a cool, bright place to sprout thick, sturdy shoots.

Planting Potatoes

Potatoes love rich, moist soil that’s been gradually improved with organic matter such as well-rotted compost or manure. Avoid poorly draining soil to prevent tubers from rotting. A sunny spot on the plot will encourage the strong growth you’re after.

Plant first earlies once the soil has begun to warm up in early spring. Second earlies are planted a few weeks later, while maincrops follow on a couple of weeks later still, in mid-spring. You can use our Garden Planner to check the best times to plant in your area, based on data from your local nearest weather station. The Planner’s also a great resource for browsing variety descriptions and, of course, to lay out potatoes on your plan so you’ll know exactly how many seed potatoes you’ll need to fill the area you have.

Plant seed potatoes into dug trenches or individual planting holes. Plant your tubers around six inches (15cm) deep, and space them a foot (30cm) apart along the row. Additional rows of early varieties should be spaced at least 18 inches (45cm) apart, while maincrops need a minimum of 30 inches (75cm) left between rows.

“Hilling — Hilling soil around potatoes increases yields and prevents tubers going green

Growing Potatoes

Shoots should poke above ground within about two to three weeks. They’ll tolerate very light frosts but are best covered over with row cover if something colder is forecast.

Once they reach six inches (15cm) tall begin hilling up your potatoes. Hilling mounds up the soil along the row to encourage more tubers to grow and to reduce the risk of light exposure, which turns them green. Use a hoe to draw up the surrounding soil around the shoots, leaving the very tops exposed. Hill in stages like this each time the foliage reaches a similar height above soil level, and continue till the mounds are either a foot tall or the foliage above has closed over.

Remove weeds early on, but fast-growing potatoes soon crowd out any competition. Potatoes need ample moisture for all that growth though. Water thoroughly in dry weather to enable tubers to grow to their full potential, free of any cracks or hollows.

Harvesting Potatoes

You can harvest tubers small as ‘new’ potatoes as soon as the plants begin to flower a couple of months after planting. Continue harvesting early varieties in stages from this point on, leaving the remaining plants to grow on until needed. This staggered approach to harvesting allows you to enjoy potatoes at their freshest and tastiest.

Maincrop potatoes are usually harvested towards the end of summer or in early autumn once the foliage has died back. Leave the tubers underground for a further two weeks then, on a dry day, lift them up with a fork, taking care not to accidentally pierce any of the tubers. Brush off excess soil, let the potatoes air dry for a few hours then store out of the light in a cool but frost-free place.