Friday, September 19, 2014

Sweet Potatoes

Half dug up, half for later
Usually I dig up my sweet potatoes at the end of September, but with the temperatures getting cooler I wondered how much they were actually growing. You can't store sweet potatoes at temperatures under 55F. How could they grow when the air temperatures get down to the 40Fs every night? And tonight it is supposed to be in the 30Fs. I'm guessing the potatoes might be better if harvested earlier. So I dug up half of the sweet potatoes. I'll dig up the other half at the usual time. I'll find out if there is any appreciable difference between the two.


I have three types of sweet potatoes. The first contender is Beauregard. It is a typical sweet potato you find in American markets. I should have dug up three plants. I found one. The other two had died. The problem was this spring. I planted one week earlier than before and we got a cold snap (usually I plant on June 1st). It got down into the 30Fs. There wasn't a frost, but the Beauregard potatoes did not like it. I think it made them too weak to compete with their neighbors. The one plant that did survive produced very small tubers for a total of 8.9 oz. Pretty pitiful for the space of three plants.


Garnet had five plants and they mostly produced. I have a range of decent, but not big tubers and tiny little ones. The tiny ones were made by vines that had rooted as they grew, so not the original plant. Typically in our climate these won't produce anything at all. Extension services in New England usually tell us to put down black plastic and plant them a foot apart. In the south you can plant them three feet apart and they will spread into the whole area. The vines will root and produce decent tubers from that. This year I placed them a bit farther apart than normal to see how they would grow. Well Garnet obviously used the extra space to root. They produced a total of 9.14lbs. For 1.8lbs per plant which is decent but not stellar.


Next on the contender list is Purple. I got these a few years ago from Norma and have kept growing them every year as they do so well here. In other years they have made long snaky tubers that are a little hard to use, but this year they made huge monstrous tubers.

The biggest was 1lb 7.4oz. Purple did not root like the Garnets did. They just produced a lot in the area they were planted. I pulled three Purple plants. They produced 9.76 lbs for 3.25 lbs per plant. Wow that is a lot of poundage.

I had 21 plants total in the bed if they were all this productive I would have a harvest of almost 70 pounds in a 32sqft area. Of course I don't want to plant all Purple sweet potatoes. I like about half purple and half orange.

In the past I've had extensive insect damage that makes the skins inedible. I had to peel to eat them. The flesh was fine, but it meant I couldn't just roast a sweet potato to eat it. The Beauregard are the worst affected with the Garnet being the least. This year there is very little damage. A couple will have to be peeled, but most can be eaten anyway I like them. Whoohoo! I wish I knew why it was so much better this year. I haven't a clue what eats them. Maybe the sow bugs? But I'm sure I'll have bad years again. I was thinking of dumping Beauregard anyway and now that I've found it can't handle cold snaps in the spring, it has sealed its fate. I'll probably split the bed between Garnet and Purple from now on. Though if I can get my hand on some Covington slips I would love to try that one as they are supposed to grow well here.

The total harvest from this half of the bed was 19lbs 7.2oz. Since half the bed is about 16sqft this was a pretty good harvest even with Beauregard not pulling its weight. Last year I grew them in the wooden raised beds. This year they are in the brick raised beds which are warmer. Last year half a bed produced 15 pounds, so I'm happy with the added production and will keep them rotating every other year in the two brick beds. I can't wait to see what the rest of the harvests brings. It might be more. It might be less.

After they were harvested I put them out on the brick path to dry out for a bit. Then turned them over and let the other side dry. After wiping the dirt off with a dry rag I packed them up into a clear plastic box. Farmers here use greenhouses to cure their sweet potatoes, and my clear plastic box is like a mini greenhouse. I spread the potatoes in multiple layers separated by a couple of grates.

The reason for the greenhouse is that sweet potatoes are supposed to be cured at 80F-85F and 90%-95% humidity for 4-7 days. I don't have those conditions. So I do it in a plastic box in the sun. I don't close the lid all the way though as that would get mold to form. And I'll cure them for a longer period than a week as they only get warm enough for a short time during the day. It isn't perfect, but it works. My sweet potatoes always last until basement starts warming up in the summer. If I have any leftover then I cook them up and freeze them.

Now the long wait before eating them begins. I hate waiting. But they won't develop their sugars until after they are cured and stored for a few weeks. I might break into them earlier as they are still good starchy and not sweet, but not quite as good.


  1. WOW! That is one HUGE tuber! Never tried planting those varieties so might do that next year. I took one tuber from store and made slips but only one actually grew after transplant, so not sure what I'll find when I dig them.

  2. Ditto Jenny - that one in your hand is huge! And if the 2nd half of the bed is like the first, it will be one impressive haul as well.

  3. Those look amazing! You have totally inspired me to give them another try this year after a complete failure last year. The purple ones look like our regular kumara here in New Zealand.

  4. Great sweet potato harvests, Daphne! I love growing sweet potatoes, because they seem so easy. (at least down here in South Alabama.) And they sure do taste great!

  5. We tried growing these last year with no success at all.

  6. A very interesting post Daphne. I didn't know about the need to cure the Sweet Potatoes, nor about storing them for a while to let the sugars develop. I know that many people here in the UK have had poor results with growing them (like Sue), mainly because our weather conditions are not suitable. I think if I were to try them I would grow them in a big tub, so that I could adjust soil composition, temperature and moisture more easily.

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  8. Maybe I'll get it right this time... Too bad the Beauregard didn't handle the cold snap. I generally plant mine out by June 1st but I can't remember it ever getting down in the 30s. That purple one is a beauty! Norma kindly shared one of the purple tubers with me, and I have 5 planted this year. I can only hope they are that productive here!

  9. Those are awesome. I have ours growing in our containers, I wasn't sure when it was time to harvest, or how long to leave them in before disturbing them. I think once all this rain has gone and the containers have dried out a bit, I'll dump them out and see what happened.

    Nice job, but then again, you always do a nice job on your harvests. :-)

  10. Wonderful harvest of sweet potatoes. I have never grown them and didn't know you should wait to eat them. It is suppose to get in the 40's one night here but so far no 30's yet. Hoping it will be awhile! Nancy

  11. I saw you on someone's blog list and when I read the post title I couldn't resist a visit. I love sweet potatoes, but haven't harvested ours yet. We got a late start due to a problem making slips so I'll hold off as long as possible to harvest.

    Your grates between layers is a wonderfully clever idea. Looks like oven racks(?) or could be! I'll have to keep my eyes peeled for something similar and give your idea a try.