From Slips to Supper: A Guide to Growing Sweet Potatoes in the UK. Though a Tropical Plant They Can Be Grown in the UK. Discover How by Following The Advice and Guidance Below.
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For many UK gardeners, sweet potatoes might seem like an exotic crop best left to sun-drenched climates. But with the right approach, these delicious, vitamin-rich tubers can thrive in British gardens, even under our famously unpredictable skies. The secret lies in understanding their tropical nature and adapting your gardening techniques to provide the warmth and care they crave. Here’s your step-by-step guide to a successful harvest.
The photo above is of sweet potatoes growing in Vila Franca do Campo, in the Azores. This is where I first studied how they grow and decided I should try them in the UK. As our climate warms they will become much easier to grow and may become a plant more of us grow was we adapt to new ideas!
Start with the Right Sweet Potato Variety
Success begins with selection. Opt for varieties specifically bred to perform in cooler climates with shorter summers. ‘Beauregard’ and ‘Georgia Jet’ are excellent, reliable choices for UK growers, prized for their faster maturation and better tolerance to our conditions.
Begin with ‘Slips’, Not Spuds
Unlike traditional potatoes, you don’t plant a sweet potato tuber. Instead, they are grown from ‘slips’—these are small, rooted cuttings or sprouts. You can produce your own slips or purchase slips from specialist suppliers in spring. This gives you a healthy, disease-free start.
Master the Timing: Patience is Key .. as with all gardening
Sweet potatoes detest the cold. Wait until late May or even June to plant them out, ensuring all risk of frost has passed and, crucially, that the soil has had a chance to warm up properly. Planting into cold soil will stunt their immediately growth.
Create a Sweet Potato Sun Trap
Heat is the non-negotiable ingredient for success. To maximise the warmth your crop receives:
Lay black polythene or horticultural fleece over the soil a few weeks before planting. This acts as a solar panel, absorbing heat and warming the earth beneath. (This is one of the few times you will see me recommending plastic fro anything in the garden!).
Consider growing in containers or raised beds against a sunny, south-facing wall for extra radiated warmth.
5. Feed for the Roots, Not the Leaves
Once established, your feeding strategy should focus on encouraging plump tubers, not just lush foliage. Use a high-potassium fertiliser, such as a liquid tomato feed, once the vines begin to run. This promotes strong root and tuber development.
6. Know When to Harvest
Your harvest window is in September or October. Watch for the leaves turning yellow as the days shorten. The most critical rule is to dig up your tubers before the first autumn frost, which can damage them. Use a fork to avoid bruising the delicate skins. Be very careful when digging.
7. The Secret Step: Curing for Sweetness
Here’s the step that transforms your homegrown crop from starchy to sublime. Curing is essential to develop the sugars that give sweet potatoes their characteristic flavour and texture.
After digging, gently brush off soil (do not wash).
Place the undamaged tubers in a warm (25-30°C) and humid place for 10-14 days. A greenhouse, propagator, or even an airing cupboard can work.
After curing, store them in a cool, dark, and well-ventilated spot.
Growing sweet potatoes in the UK is a rewarding challenge that brings a taste of the tropics to your plot and plate. By focusing on warmth, timing, and the crucial curing process, you can enjoy the incredible satisfaction of unearthing your own homegrown, sweet and creamy harvest. Why not give it a try this season?
