Looking for the next best thing to grow in your outdoor space? Sweet potatoes may just be the crop for you. They offer a starchy and sweet flavour when cooked and have found their way into many
delicious recipes like vegetarian curries and roast dinners.
You'll find hundreds of varieties of sweet potato around the world, but the one we Brits are most familiar with is the Beauregard. This is because it performs well in the temperate weather conditions found in the UK. Sweet potatoes usually prefer more humid conditions during the growing process.
If you're looking to add sweet potatoes to your ever-growing garden of wonderful fruit and vegetables, you'll also be pleased to learn of their many health benefits:
- Their high vitamin A content can help keep your eyes healthy, boost your immune system, and aid the function of your heart and kidneys.
- Your risk of cancer could be reduced thanks to the carotenoids in sweet potatoes.
- They can also lower your "bad" cholesterol – otherwise known as LDL – and therefore knock down your odds of suffering heart disease.
Get started on your new growing adventure with the sweet potato today. They're relatively straightforward to grow – even if you're a novice! Read on to find out how to grow, plant, care for and harvest sweet potatoes in our comprehensive guide below.
How to grow sweet potato
Before learning how to grow a sweet potato, you'll first need to know when to start growing them. You'll want to begin the growing phase in February, March or April so they're ready to be harvested in August, September or October.
Sweet potatoes don't fare well in cold temperatures – especially when they're in their early stages of growth. This crop thrives in temperatures of 21 to 26°C, which is why you want to start growing your sweet potato plant indoors or in a polytunnel.
Unlike many other vegetables which are grown from seeds, sweet potatoes are grown from cuttings referred to as 'slips'.
To give them the best chance of growing, we recommend popping the sweet potato slips in water for a few days to perk them up a bit. You'll then place the sweet potato slip in small pots filled with multi-purpose compost. Try to bury as much of the stem as possible because this will allow the root to develop properly. Once potted, cover the sweet potato plants with a plastic bag or place them in an unheated propagator.
Your sweet potato vine will remain indoors until temperatures are warmer, usually in May or early June, when they typically root or show signs of growth. While you wait, you can prepare the ground for planting them out.
How to plant sweet potatoes
Choose a spot that will get plenty of sun but will also remain sheltered. If this isn't available in your garden, a
polytunnel would be a wise investment.
Once you've found your spot, remove all weeds from the immediate area and add plenty of organic matter like garden compost. Next, cover the area with black polythene. This will warm the soil and stifle weed growth in the build-up to your sweet potato being planted out.
Your sweet potato plants will need plenty of space to grow, with some stems reaching up to 1.5m long. Therefore, we recommend planting your sweet potato slips by cutting through the polythene at roughly 30cm intervals. Once they're in, water well and add a
cloche or fleece to keep them warm enough.
Caring for your sweet potato plant while it grows
Your sweet potato vines will grow for several months until it's time to harvest, which means they'll need a bit of TLC occasionally to keep them healthy.
Start by watering them regularly to encourage them to grow larger and provide them with a high-potassium liquid feed every two weeks. This will help them resist pests and common plant diseases as well as increase their ability to withstand colder weather conditions.
Sweet potatoes can grow without support but as the vine grows larger, your garden will look neater if you find ways to support them. You can do this by pinching out the tips of longer stems. This should encourage bushier growth, which will leave them better supported.
Common problems your sweet potato plant may face
As with most vegetables, growing sweet potatoes isn’t without a spot of bother now and again. Look out for the following and deal with them efficiently to prevent damage to your crop.
Glasshouse red spider or two spotted mites
These can be easily spotted as you'll see your leaves become marked with spots and they may be covered in webbing. The leaves will drop off prematurely, so you must act fast to keep your plant safe.
These pests thrive in warm and dry conditions, so frequently mist your leaves to prevent them from appearing. Should you still discover them, remove them with a high-pressure water spray.
Whitefly
Another pest that may invade your sweet potato plant is the small white fly. They will suck sap and excrete honeydew all over the plant. This may lead to mould forming. The best way to get rid of these pests is to use sticky traps.
Harvesting sweet potatoes
If you were wondering how long sweet potatoes take to grow, the answer is around 100 days. But you can also tell when they're ready to harvest because the leaves will have turned yellow and fallen off. They must be harvested then and there to avoid the inbound frost killing the plant.
Harvesting sweet potatoes is easy! Simply grab a garden fork or spade and lift the tubers out of the soil. It's recommended that you then use them immediately, but find a cool and dry area that gets plenty of ventilation should you wish to store them in your home. Be sure to also keep an eye on any signs of rot and dispose of the potato if this appears.
To get the most out of your harvest, consider propagating your sweet potato. This will give you fresh sweet potato cuttings to grow the following year. To do this, take cuttings from the plants in summer and root them in water. After this, pot them the same way you did before and leave them in a frost-free spot until next spring.
Get in touch with us today to find out more
Sweet potatoes are a fun and straightforward vegetable to grow in your outdoor space – so long as you've got the correct growing conditions for them. That's why we recommend growing them in a polytunnel to provide them with the necessary light, shelter and humidity to thrive. We have
a range of polytunnels available in an array of sizes, so you can find the right fit for your space.
Got a question about growing sweet potatoes in a polytunnel? Simply call us on 01282 811250 or email
info@premierpolytunnels.co.uk and we'll be happy to help!
Plus, don't forget to check out our
blog for other fruit and vegetable growing guides too.