How to plant and grow Potatoes

People get very obsessive about how they plant potatoes, as though there was a right or wrong way. There are those that swear by holes rather than drills and others who only grow under black plastic, hay or straw. Each to their own. I use two methods. In open ground I cultivate the soil so I can draw a mattock easily through it and make V-shaped drills about 23cm (9in) deep and 90cm (36in) apart. I then place the seed potatoes along the bottom of these drills about 45cm (18in) apart. The wider they are (up to 30–60cm/12–24in), the bigger the crop from each plant and the bigger the individual potatoes. It follows that maincrop baking potatoes should be planted at a wider spacing than new potatoes grown for eating small and boiled whole. I then use the mattock to draw the soil back over the drills so that the soil forms a distinct ridge. 

The other method, that I use for raised beds is simply to make holes with a trowel or dibber into which I pop the seed potatoes in a grid about 45cm (18in) apart. This is very much easier and produces just as good results – especially for first earlies. 

However you plant potatoes, the top-growth is likely to appear before the last frosts and frost can blacken the leaves exactly as though a blowtorch has been at them. You can avoid this scorching by earthing them up as soon as all the leaves have appeared and the plants are about 15cm (6in) tall. This is done on open ground by drawing soil up with a draw hoe or mattock from between the rows and covering all but the very tops of the green leaves. On raised beds I use either a layer of compost or straw but compost is preferable because damp straw is slug heaven. Earthing up also ensures that any growing tubers remain covered from light and so stop turning green and poisonous. It also supports the haulms when they are at their floppiest. And lastly, but by no means least, the increased thickness of the soil covering works as a protective layer against blight spores being washed from the leaves down into the potatoes. 

Seed potatoes, especially of early varieties, grow faster if they are ‘chitted’. This means exposing them to light with most of the eyes upright so that they develop strong, knobbly buds. Chitting is really just the start of the growth of the potato – effectively like germinating and growing seedlings in a propagator before planting out. 

They will take about a month if they are placed on a cool (but frost-free) windowsill. If you have them, egg boxes or trays are ideal for this but I use seed trays, which work very well. 

Potatoes will grow unchitted too – in fact you cannot stop them growing – but if you chit them they have a head start once they are planted. This can be important in cold areas because potatoes are not hardy. A late frost can scorch the foliage or even kill the potatoes. Chitting is also important in areas prone to blight, as the tubers have maximum chance to develop before blight strikes – which is rarely before July.

Family	Solanaceae
Growing zones	N/A
Growing season(s)	cool weather: spring
Spacing	12 inches
Start indoors or direct sow	direct sow “seed” potatoes
Indoor sowing date	N/A
Earliest outdoor planting	4 to 6 weeks before average last frost
Soil temperature	50° to 80°
Fall planting	12 to 14 weeks before average first frost
Sun needs	6+ hours
Water needs	moderate
Harvest category	one harvest
Troubleshooting Tip	Although potato leaves are frost tolerant, they will die in a hard freeze. If a freeze is imminent and stems have already emerged, cover the plants with a light temporary mulch or cover. If leaves experience freeze damage, clip affected leaves off; often the plant will rebound with new growth.

 

Snapshot	Potatoes can be one of the most fun vegetables to grow and harvest. In cold-season areas, the plants grow all season for a late-summer harvest. In warm-season areas, tubers  are  harvested  in  early  summer, leaving space for a succession crop. Some varieties (such as red potatoes) harvest as early as 60 days from planting; other varieties (such as White Russet) may take four months.
Starting	Purchase “seed” potatoes from a local farmers’ co-op, a feed store, or a reputable online seed supplier. These are small potatoes produced in a certified disease-free environment. When the soil is able to be worked in the spring, dig trenches 4 inches deep with a hoe, and set the seed potatoes in the trenches 12 inches apart. Return the soil to the trench, covering the seed potatoes completely, and mark your rows. Depending on the weather and soil temperature, look for tough, dark green, rosette-like stems to emerge in about 3 weeks.
Growing	When plants are about 6 inches tall, take a hoe and pull the surrounding soil up to make “hills” around the plants. Repeat this process about 3 weeks later. Potato tubers begin growing at soil level, but if exposed to light, they develop green skin, which is toxic in large amounts. “Hilling” provides space for tubers to grow without sunlight. Keep the ground evenly watered but not saturated.
Harvesting and Storing	Watch for the vines to begin losing their deep green color and vigor. This is called “dying back.” Wait about 3 weeks. Then take a shovel and dig about 12 inches away from the main plant, loosening the soil around it. Tubers should be most evident right at soil level. Be careful handling the tubers because they bruise easily. At harvest they are ready to eat, but if you want to store them longer, place unwashed tubers in a cool, dark location for 1 or 2 weeks before moving them to the coolest spot in your home or a root cellar (50° is ideal).
Common Problem	Early blight, which affects tomatoes, also causes yellowing spots on potato leaves. Do not plant potatoes where tomatoes have grown in the past three to four years. Mulch using organic hay or straw.