Thinking about growing sweet potatoes? Top tips for perfect roots
If you’ve never tried growing sweet potatoes, we urge you to give them a go. They taste great. They are packed full of vitamins and minerals, fiber and nutrients. They also have attractive foliage and flowers that make a pretty feature in your garden.
The benefits of growing sweet potatoes don’t end there. They are versatile.
Grow them in your garden, in containers, on a patio, up a trellis or even as a trailing houseplant. They also make excellent temporary groundcover plants.
They are as useful in the kitchen as they are in the garden. You can boil, fry or bake sweet potatoes and use them in casseroles, soups and salads. You get a bigger hit of vitamin C from sweet potatoes than your standard potato too.
Remember that sweet potatoes are a warm-weather crop: they like a sunny garden with plenty of heat. If you live in the north, think about making space for your sweet potatoes in a conservatory or indoors until the warm weather arrives.
There are so many plusses to growing sweet potatoes – why not give it a go? We’ve got everything you need to get started here.
How to grow sweet potatoes
Sweet potatoes need temperatures of 20-25 ֯C to produce the best crop.
If you live in a warm climate, you’ll be planting out your sweet potatoes as soon as the weather warms up in spring.
In colder climates, you can grow sweet potatoes in a conservatory or indoors on a windowsill until they are ready to plant out in the summer, in late May and early June.
Here are some step-by-step instructions for growing sweet potatoes.
Growing sweet potatoes from cuttings
Sweet potatoes are grown by planting the sprouts (known as ‘slips’) that grow out of the potato (known as a tuber). You can either buy slips ready to go or encourage tubers to sprout, cut the shoots off and plant them.
Buy your slips from a reputable nursery or mail-order supplier.
Store-bought sweet potatoes are usually treated to stop them from sprouting on the shelves – so you may have less luck trying to grow from them. The store-bought varieties are not always suited to the conditions of a home garden either.
That said, if you want to try growing sprouts from a sweet potato tuber, use this method:
- Prepare your tubers about 6 weeks before you want to plant the sprouts.
- Put tubers in a tray of moist sand, perlite, sawdust or leaves and keep them in a warm place to encourage sprouts to grow.
- Once the shoots are 6-9 inches long, cut them cleanly off the potato with a sharp knife.
- Cut off the bottom inch of each slip to prevent disease.
- If you are growing indoors, plant your slips in pots of compost and keep warm and well-watered while they take root. Re-pot as they grow bigger. If you are planting outdoors, read on for more tips.
Growing sweet potatoes in the garden
Deciding when to plant out your sweet potato sprouts will depend on local conditions.
In the north, you’ll need to start preparing the ground in late March and encourage the soil to warm up by covering your sweet potato patch with black polythene.
By warming the earth and keeping weeds down, you’ll give your indoor-grown plants the best chance when you plant them out in late May and early June.
If you live somewhere hot, you shouldn’t have trouble encouraging your sweet potatoes to grow outdoors.
Here’s a perfect setup for growing sweet potatoes in the garden:
- Choose a sunny warm spot with well-draining soil that retains moisture.
- Dig in some compost but avoid too much nitrogen-rich material, it will encourage foliage rather than roots.
- Make 10-inch high x 10ft long ridges of soil, with about 3ft between rows. A 10ft row produces about 10lbs of potatoes.
- For cold climates, cover your growing area in black polythene to keep warmth in. To plant, make slits in the plastic. You can also add fleece to keep heat in.
- If you’re wondering how deep to plant potatoes: they should be about 4-6 inches deep with just the top leaves showing. Allow about a foot between each plant.
- Firm the soil around each plant and water well.
How to care for sweet potatoes
Once your plants are in, you’ll want to keep an eye on them to see how they develop.
Add a mulch two weeks after planting (if you are not using black plastic) to help keep weeds down and retain moisture in the soil.
If you have a dry spell of weather, be sure to water the plants once a week. But be careful not to overwater. Sweet potatoes can survive dry periods well, and the last thing you want is soggy rotten roots.
To make a nice feature, think about training your sweet potato vines up canes or a trellis. Growing this way can give plants more space and light too.
Growing sweet potatoes in containers
You can grow sweet potatoes in containers or grow bags and have them in your conservatory or on a warm sunny patio.
They make a beautiful feature because you can train them up a trellis and the leaves and flowers are attractive.
Enjoy the foliage through the warm months and then harvest your potatoes in the autumn – it’s a win-win!
- Use a peat-free mix in containers and make sure there are plenty of drainage holes.
- Keep your containers moist.
- Use a feed rich in potassium.
- Avoid fertilizers full of nitrogen – you will get loads of leaves, but stunted roots.
How long does it take to grow potatoes?
Sweet potatoes take about 4 to 5 months to grow. You will know they are ready when the leaves start to turn yellow and die back. This is the best time to harvest them.
Be careful as you dig them up: you don’t want to damage the skin if you are planning on storing them.
Growing sweet potatoes: top varieties for the backyard
We’ve picked out 3 of our favorite sweet potatoes for gardens and containers here, taking into account both hot and cold climates.
- Georgia Jet – deep orange, great for northern climates
- O’Henry – a compact sweet potato which is excellent for patio containers
- Beauregard Improved – a reliable root with beautiful pink-orange flesh
Now you’ve got all the info you need, what’s stopping you? Start on your sweet potato patch today and see what works best for your local conditions.
Remember, if you don’t have much room, there is always space for a container or two.
You can even try growing sweet potatoes on a sunny, warm windowsill indoors. Don’t forget to water!