Sweet potato harvest

ClareBroommaker's picture

Due to rain, rain, rain in late spring, our sweet potatoes were late to go in to our little city garden. Then the vines grew like gang busters and I was afraid maybe there was too much nitrogen in the soil which might make for some stringy potatoes. And--- yah, I accidentally planted moonvines in among the sweet potatoes. They look an awful lot alike. I did not realize it until the white flowered moonvines bloomed! Then there were also pink morning glories (weeds) galore in the same area. Sweet potato flowers are purple. So what a tangled, green, blooming, viney jungle that area was!

Well, my husband hand dug this afternoon. Literally he used only his hands. Tomorrow I'll go over it with a spading fork to find any he missed. He dug two milk crates of potatoes. Yes, some of them were stringy, but not as bad as I feared. And even the stringy ones just looked immature, not over-nitrogen'd.

Here's a glimpse,

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alice's picture

Wow, brilliant, well done. There's nothing like a good harvest to encourage the gardener. =D

Blueberry's picture

Sweet potatoes, cracklin corn bread, and ham, so what time is supper?

ClareBroommaker's picture

Supper will be in about two weeks. I've got to get those sweet potatoes cured first! Late as they were dug, I will have to use my usual method of laying them out on the lawn with a plastic sheet over them to retain humidity from the ground and heat from the sun. This works, but I have to go out 3-4 times a day to turn the potatoes so the warmth makes its way well through the entire mass. When cured, they go to the basement.

BTW, there will be heavily salted greens on the menu, too. Hope it doesn't shock the timid, but there will be some fat trimmings from the ham cooked down into the greens. Did I ever mention I grew up in Tennessee? Can you hear my accent?

I'm hoping Sweet Tater Man will be able to show us his mountain of potatoes....

Blueberry's picture

So Collards, Mustard, or Turnip Greens looking forward to supper!!!!!!!!!

Sweet Tatorman's picture

In the Spring I had posted a photo of hilled ridges in preparation for planting. Part of the rational of ridges is that it facilitates digging without damage. Typically I only nick or cut 1 or 2 out of a 100. This year I planted in blocks of 4 rows each 10 ft long. The first photo shows vines cut and pulled out of the way for one variety out of 5 grown. The second photo is post digging. Typically I let dry on the ground a few hours before gathering to facilitate brushing off the soil. Sorry if upside down. No matter how I rotate the photo in editing it does it's own thing when uploaded.

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Sweet Tatorman's picture

Photo attached

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mountainmoma's picture

I am about to plant some in a few weeks

Sweet Tatorman's picture

Having retired from a career as a test engineer I am a very data driven gardener. My garden record book is in my lap as I type. That photo was taken last Fall. That year was the lowest yielding year out of 13 years of data. Averaged over the 5 varieties grown, yield was 0.45 lbs/ft^2 covered by foliage and 1.57 lbs/plant. Long term averages are on the order of 0.60 lbs/ft^2 covered by foliage and 2.0 lbs/plant. From some of your past posting I have the impression that you do not have a hot climate. Sweet potatoes require a lot of hot weather to yield well. If you are familiar with the growing degree day [GDD] metric, you need at least 1800 GDD with a base temperature of 60F to get any reasonable yield.

mountainmoma's picture

I live at 2400ft, it is very hot here in the summer, too hot for many things, I dispair of ever being able to get a second crop of short season potatoes, but will try this year.

I tried sweet potatoes once before, I think I did not have the density I should have, I did not keep records but recall decent amount per plant, although not as large as I would have liked.

I have been working on slip production for months, and they cannot be planted yet. I have the japanese type, purple outside, white flesh and an all purple type. I cannot grow on open ground as you do because of gophers, so they will be in a raised bed, which makes harvesting hard, I recall, due to them being brittle, they break easier than potatoes. I plan on planting them 1 ft apart.

WOuld love any other tips, as what I read online is always hard to interpret, so I wonder about fertility and watering. I would hope I could get at least 1 lb per plant, I should have about 40 plants.

Summer days temps are in the 80s and above sometimes over 100 which is miserable, Some of the summer nights cool off from that, which is thankful to cool the house down, but never cold, and my growing season is long, into October

Sweet Tatorman's picture

Do the gophers just eat the roots or like groundhogs do they eat the foliage too? If the later, you would need very large raised beds as the vines can extend out 10' or more. If gophers do eat the foliage and you are forced to use raised beds you would benefit from varieties that tend to have short vines. Really short varieties only extend outwards 3 or 4' from the planted location.
When I refer to ft^2/plant this is the figure obtained by dividing the area ultimately covered by foliage by the number of plants. I have experimented with various planting densities and can make the following generalizations down to 2.5ft^2/plant which is as dense as I have tested. With all else equal, lower ft^2/plant yields lower lbs/plant but higher lbs/ft^2. Average potato size decreases with lower f^2/plant. If you have access to climate data for your immediate locale it would be worth calculating the GDD with a base of 60F for an average year. If you get less than 1800 GDD you need to find some short season varieties. One I can recommend is a commercial variety type 8633 which is also a very short vine variety. It's only downside is that it is a poor slip producer. It has the highest average yield of varieties I grow. Another of my varieties "Oakleaf" is a good yielder on lower GDD and very good slip producer but is a long vine variety ~10'.
Assuming you have soil with adequate P and K as well as the minor nutrients, the only thing that you would be adding is N. I have not seen any yield benefit beyond 75 lb/acre added N and the difference in yield between 50 and 75 lb/acre is small. Water requirements will be strongly dependent upon sun, temperature, wind, and humidity. In my locale I try to insure that they get at least an inch/week. Once established they are known to be drought tolerant but I have not experimented with this myself as I can irrigate without limitation.

mountainmoma's picture

Raised beds are expensive, so it is always about maximizing yield per square foot, if you dont have to pay for starts. Which is a reason that I start my own slips. Gophers do not climb well, and they usually stay underground, they are rarely above ground.

So, for example, I grow regular potatoes at 1 sq ft per plant, because I save my own seed potatoes and I need to maximize yield per sq ft.

I do not add nutrients in some kind of chemical additive farm way, so I do not have a bag of nitrogen to add so many pounds of. But, no matter, I will just grow them as I did before. I will report back next fall with yield information.