{Sigh} I was so excited this morning to dig ‘em up and witness my bountiful yield. This is my 1st time doing sweet potatoes and it’s a bust. About 8 slips over four 15 gallon grow bags. Just to get about 1 potato each or a few little ones.
Looks like 1-2 servings of fries and maybe 2 baked potatoes. Smh. This is 4 month’s investment of time and money. The big ones came from 3 Japanese Purple Sweet Potatoes slips I bought on Amazon for like $15. Me and that seller have beef now. Where’s the purple?! Any tips for a bigger yield so this doesn’t happen next time or is this actually the norm?
by Global_State8539
9 Comments
Yup same feeling with harvesting sweet potato.
Two separate issues. First, about the varieties, I have not grown Japanese Purple and cannot comment on that. But, like you, I would expect them to be purple.
I do grow sweet potatoes in grow bags, usually 15-gallons, like yours. If I plant more than 3 slips per bag, they do come out skinny and small. So crowding them does not pay off. The other factor that has an even greater influence, in my experience, is how long I let them grow. I have found that letting them keep growing way beyond their official “date of maturity” results in much nicer looking tubers. I pay no attention to the recommended “120 days” or whatever. I just leave them in place until the first frost of the year has been forecast.
For me, in NE Texas, that means I plant them towards the end of April and dig them up towards the end of October. I also try to select “bush” varieties instead of ones that are known to have long, rambling vines. My favorite, year after year, is Vardaman, from Mississippi. I buy the slips from Steele.
[https://sweetpotatoplant.com/](https://sweetpotatoplant.com/)
Footnote, I harvest and eat some of the young, tender leaves all spring and summer. Usually make them as a stir-fry. That way, even if my plants don’t form nice tubers, it won’t have been a complete fail.
https://preview.redd.it/v0esb159fwph1.jpeg?width=1538&format=pjpg&auto=webp&s=827ad54864d92c6cd31c2999fb2722861eb7262c
I’ve got 4 slips in a 30g grow bag. They are bulging out of the soil right now. Can’t wait.
I think next year perhaps either wait until the last possible date to dig them up, or dig up one grow bag, see how they are and make a decision from there. This is my first year growing them too and I dug one of mine up at the prescribed grow date from the label(100 days I think) and my harvest was similar to yours. I asked my family, who always have huge sweet potatoes and they said leave them in the ground until the last possible day you can. The sweet potatoes at some point stop putting energy into the leaves and there is a several week period where they then focus on making the roots bigger. So like everything in the garden, it has its own schedule.
The three large potatoes look like murasaki sweet potatoes, which have purple skin and yellow inside. Its confusing because murasaki loterally means purple in japanese. Theres another variety entirely that has the purple flesh. And the murasaki sweet potatoes you grew take a long time to mature, so possible you harvested too early.
Well growing sweet potatoes in containers is tricky. I only grow in the ground and have them decently spaced out – maybe one every 2ft as they like space and they like to ramble, rooting as they go. I can’t comment on the variety but I do leave mine in the ground until early November, tempting as it is to take some now.
How did you feed them? I think they don’t like too many nutrients, especially nitrogen, if you want more roots
It looks like you could have let them go longer, the plant didn’t look deadish. Also, 4 months is not very long for sweet potatoes. And in a bag, they will be restricted in size.
I did containers a few ways: I found the less tall containers didn’t provide enough depth for the roots and resulted In a limited harvest.
The deeper containers had no issues and got larger harvests.
I agree with others that they likely need more time than suggested, and is also weather dependent. Cooler and darker days/weeks will mean you need to make that up by extending the time until harvest.
I also let mine go as long as possible in my limited Northern climate, usually until frost.
I built a 50cm tall, open-bottomed raised bed specifically for sweet potatoes. Because the soil will heat up sooner (for earlier planting) and remain warmer for longer (more active root zone + extended season with higher soil temps relative to ground temp).
I’ve also found they’re super thirsty when in containers so, the raised bed is also less work, because the larger soil volume has a higher water capacity.