Page 33 - ALG Issue 3 2020

Grow sweet potatoes
If you want to contribute to reducing veg air miles and reduce the weight
of your shopping bag, why not grow sweet potatoes? They are easy to grow, virtually pest and disease free, and store for months.
I have been growing them in the same place and from the same stock for fifteen years. I garden in Hythe, Kent, half a mile from the sea. We don't get much more than 50cm a year rainfall, but it is sunny and while the closeness of the sea cools us in summer we do get a long growing season. However, I’m sure sweet potatoes would be worth growing much more widely.
I grow in a DIY garden frame where I’ve built up the soil level to give 2’ depth.
I have also been successful with half plastic compost bags sunk into the soil and then filled to double the soil depth.
I was given a small tuber of Tainung 65 one April by a fellow allotmenteer. I put it in damp compost in a warm place where the root end grows shoots. When these were six inches long, I cut them off and put each into a 9cm pot on a north- facing but warm kitchen windowsill. At the end of May, the rooted slips were planted deeply and at an angle in the garden frame, about 20cm apart and kept covered with glass (with ventilation on sunny days) until they were growing strongly, and night-time temperatures were over 10 degrees. The soil had had a good amount of compost dug in and was given a bit of Growmore.
In dry Kent, I watered them well in dry spells with sun-warmed water, trimmed back some vines that were trying to explore the rest of the
allotment, but no other care was given until temperatures started dropping below 10 degrees – probably late October. The tubers were carefully dug up – they grow vertically and are easily damaged. I kept them for a week in a warm cupboard (over 30 degrees) for the skins to cure. They were then put in a frost-free utility room until eaten with a few inch-thick ones kept for starting the next year’s crop. Some were well over a kilo in weight. There’s plenty of advice on the web about growing sweet potatoes. You do need to get the right variety bred to yield in cooler climates – supermarket purchases are unlikely to work. A fellow allotmenteer hailing
There’s plenty of advice on the web about growing sweet potatoes. You do need to get the right variety bred to yield in cooler climates
from Sierra Leone grows them purely for the leaves (taste like spinach?) but I’ve always got plenty of spinach beet or chard, so I have never tried.
The key points are:
• Growaswarmaspossible.
• •
•
Plant slips deeply as storage roots grow from the stem.
Grow as long as possible – they bulk up late. Can wait till first frost kills top growth, but not worth keeping in the soil if temperatures go below 10 degrees for any length of time. Curing for a week at a high enough temperature seems to be essential to storage success, but then storage is very easy, and flavour improves with keeping.
Our allotments have a real problem with wood pigeons, but they don't bother with sweet potatoes. I never protect against slugs but get only slight damage to a few tubers. The only occasional problem my fellow growers and I had which raises our blood pressure somewhat,
is what we think are short-tailed voles who have been known to nibble the tops of some tubers where they appear very near the surface.
If you like eating sweet potatoes and can give them the right conditions, do have a go.
John Lewis, Hythe
Allotment and Leisure Gardener 33