It’s been a decent sweet potato year. I tested yield differences between ones left to creep and crawl and ones given climbing options.
Both varieties gave noticeably higher yields under trellis, the purple Japanese variety really pulling out all the stops in a combined test of second year growth (volunteer list from last year) and shared trellis with a melon. I got maybe 30 lbs from that one spot.
I am not sure between Vardaman and Yellow Jewel how yields were, as they got eaten quickly and I hadn’t labeled the spots, mistakenly thinking I’d be able to tell them apart upon harvest. Both were creamy and tasty, and much less floral than the purple ones (the only way I can think to describe it, it’s not a bad thing.)
The purple ones are also more starchy and fibrous, but the yields on them are impressive in the second year. In the first year they mostly vine and send down a web of roots, seemingly to prepare for next year. No wonder I’ve yet to see slips for them for sale. (These I started in my pantry from organic ones from the grocery store.)
I imagine future sowings will depend heavily on future location climate more so than preference. If I were staying put another year, I wouldn’t add any more purple ones, as I’m sure I left some in the ground already, but would likely triple my creamier varieties to 36 plants, all trellised, and see if I couldn’t get a proper scale.