Planting and Growing Sweet Potatoes

[MarkHackwell]

Soobit seems that I have ordered 33 Sweet Pottao Plants (Mistakingly ordered the second lot of 18 as didn’t realise I had ordered 15 ) so as this has been quite costly would now like to get a crop.

My allotment is on clay and I do have a big Polytunnel so should be alright in that sense. My thinking is they like free draining soil so should I mix some compost and sand into the soil before planting them? And any other advice on growing sweet potatoes successfully (I have looked on the forum at a few articles and appears with mixed success)

Thanks in advance!

[ameno]

In theory, you should probably improve the soil, but I grew some on my allotment last year, which is clay, and they did very well. Got 5kg from three plants (and this is outside, and they were planted late). It seems in heavier soils the tubers become longer and thinner, but are overall the same weight. So you get lots of fat sausages rather than the typical more oval shaped ones.

The main thing they need is plenty of warmth and sun. They also need plenty of water once the tubers start swelling, but that's not really until about mid-August onwards. The plants themselves are actually pretty drought-tolerant.
They're also very heat-tolerant. It got up to 40c in my conservatory a few times last year, and the sweet potatoes were completely unfazed (unlike the poor cucumbers, which really didn't like it).

Also, when you come to dig them out, the tubers go further than you might think. I thought I got all of mine last year, but when I came to dig the patch this year, I found a rotten one some 50cm or more from where the nearest plant had been.

Oh, and don't listen to the articles which tell you sweet potatoes don't keep for long. Those are just written by people who don't know how to store tropical crops. If you store them properly, they keep for months. Mine where still good and firm when I used the last at the beginning of March this year.
The reason they go bad on people is because they try to store them cold. The tubers are still alive, and sweet potatoes are a tropical crop. They don't like the cold. They should be stored somewhere warm-ish (low 20s is ideal) and humid. I keep mine on a high shelf in the kitchen. The small ones tend to shrivel up, so need eating up first, but the larger ones keep for months.