Page last updated 1st May 2015
How easy are potatoes to grow? What’s the yield?
Potatoes (sometimes called Irish potatoes to distinguish them from sweet potatoes) are easy to grow in containers or the ground and nothing beats freshly dug spuds.
As with most veg, potatoes (Solanum tuberosum) need well-drained fertile soils in open, not shaded, sites. In dry spells, remember to water, to ensure a good yield. Frost is a problem because the leaves will be killed, so don’t plant too early, although you can always cover up new shoots with soil or fleece if a cold snap is forecast.
Expect a yield of about 2kg per metre (4 1/2 lbs per 3ft) row for earlies; double that for maincrop. See Which variety to grow? Earlies? Second earlies? Maincrop? for definitions.
Potato planting/harvesting times
To grow your own, you’ll need so-called seed potatoes (actually egg-sized tubers), which can be ordered in advance for delivery at the appropriate planting time. Earlies and second earlies are also known as ‘new’ potatoes ie having a new and very thin skin that can be rubbed off easily. These are set in the ground as early as you dare, and can be harvested around 10-12 weeks later.
To give potatoes a head start while the weather remains unsuitable for planting, then sprout (chit) them indoors. Place the tubers, rose-end upwards, in a single layer in a tray in daylight. Which is the rose end? Look for the indentation at one end of the tuber that shows where it was once attached to the plant. The rose end is the opposite end. Plant chitted potatoes in the ground carefully to avoid damaging the young shoots, from March onwards, depending on your area.
Spacing seed potatoes
Dig a trench and heap the soil either side. Use this to cover the tubers and earth up the shoots during the growing season. Place tubers about 15cm (6in) deep, and 38cm (15in) apart. Rows should be about 60cm (24in) apart.
Be vigilant about earthing up as the shoots emerge, since the soil covering will protect them from any frost. Eventually you will have high ridges of earth that are easy to fork through at harvest time.
Protecting potato plants and crops from pests and diseases
If slugs are a problem in your garden, choose a potato variety that is relatively resistant, so the tubers are usable. Slug resistance is usually mentioned in the description.
Wireworm can also damage tubers if potatoes are grown on ground that was recently grassy, so it’s best to wait 3 years after clearing such ground before trying potato growing. Alternatively, grow some earlies in a container of compost.
Potato blight, a disease caused by a fungus, damages potato leaves so reduces the yield, and if there is a lot of blight, the spores will wash down to the soil where they will rot the tubers. So if many leaves become blighted during the summer, cut them off and burn them to protect your crop, and be sure to harvest soon after.
Blight is worse in warm humid weather and commercial growers access alerts so they know when to spray. You could check these blightwatch alerts to find out the risks in your area, and then use a copper-based fungicide spray (such as Bordeaux mixture) to keep the worst at bay, although pesticides for amateurs are not as effective as those available for farmers.