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When to harvest Sweet Potatoes

steve333_gw
9 years ago

I started some slips from super market potatoes late this spring and put them in my new greenhouse late June/early July. This was more of an experiment, as I had extra room this year in the GH, and never had much luck with sweet potatoes outside here (season was too short and nights too cold).

Well the plants have done well, at least on top. They spread over a good sized area, and have been flowering. My question is when should I harvest them? Most of what I read is for outdoor growing, and they talk about digging them just before a frost hits. Well I don't expect it will get below freezing in the GH for another couple of months, if ever. Should I just wait and leave them grow as long as possible? Or is there an optimum time to harvest sweet potatoes?

Thoughts?

Comments (15)

  • farmerdill
    9 years ago

    Not really, Sweet potatoes are tropical perennials. Just don't let frost catch them. You can remove indivual potatoes if they are getting too large for your purpose.

  • hudson___wy
    9 years ago

    I have a similar situation - planted sweet potatoes because the corn seed we ordered came back-ordered - to late to plant corn - so we planted some sweet potato slips just to experiment. We plan to let them grow until the frost gets them - but in our climate - that will be in a couple of weeks or usually before mid November - in our GH. The plants appear to be growing well - but they did not flower? I could dig one up - but think I will just wait until it is too cold in the GH for the sweet potatoes.

    {{gwi:116398}}

  • planatus
    9 years ago

    When soil temperatures fall below 55 degrees, sweet potatoes become targets for some soil-borne pathogens that damage the skins. Also, you'll want to dig them while you still have warm conditions for curing. Mine are on a high shelf in the warmest room in my house, but you can probably use your greenhouse.

    A couple of weeks ago at the farmers market, people were selling the new leaf tips as cooking greens (they're kind of like spinach). They went through and cut the greens before digging the sweet potatoes.

  • elisa_z5
    9 years ago

    Sweet potatoes flower?? I've never seen that.

  • yolos - 8a Ga. Brooks
    9 years ago

    In 2013 I had a few flowers but in 2014 I did not have any either. I was growing Beauregard Sweet Potatoes both years.

  • farmerdill
    9 years ago

    Most varieties bloom rarely if at all. Beauregard will blossom sporadically. Covington and Carolina Ruby blossom frequently.

    {{gwi:50071}}

  • vgkg Z-7 Va
    9 years ago

    After growing sweet potatoes for several years now I've learned that 100-110 days is long enough in the ground for them to develope nicely without getting "lunkers". Depending upon the variety some potatoes will split and produce ugly unbakable things which are only good for casseroles. These lunkers are caused by excessive rains on top of an already mature crop. After planting mine in mid-May I dug them up on Sept 1st and had plenty of good sized well formed bakers.

    As a side note, once I dug up the main rows I left intact the trailing vines which re-rooted and now I may have more out there to possibly harvest before first frost. Will wait and see if this is true or not. Be nice to get a 2nd crop even if they are smaller.

  • elisa_z5
    9 years ago

    Thanks for the photo farmerdill! I see them showing their morning glory "roots" :)

  • shayneca25
    9 years ago

    With direct sun,100-120 days is how long I typically leave them in the ground.

    I have an area that gets about 4 hours over direct sun and I left them in the ground 150 days. They were smaller than the ones in direct sun Ibut still very desirable in size.

    I saw some mention eating the leaves (greens) If you can post that recipe I would love to try it it.

  • blueswimmer68
    9 years ago

    I just dug up one plant that I stuck in a pot last spring because I didn't have room for it anywhere else. It's my first year growing them, and I just couldn't wait and wanted to see if it worked! I have a nice pile of small but nicely formed tubers from this small pot, so I am excited like a kid on Christmas morning to harvest the main crop later this month and serve my own sweet potatoes at Thanksgiving.

    Does anyone have tips for curing them on a small scale? I've been reading about giving them heat and humidity to form sugars. If I put them in my detached garage that gets very warm in the daytime (the sun beats in the windows and onto the roof) under a sheet with a pan of water nearby will it work even if the temps go down into the 50s at night? Thanks!

  • shayneca25
    9 years ago

    Blueswimmer,

    What I like to do is put them in a large clear plastic tub.
    Put a wet rag in the corn of the tub. I generally, dont let any of the taters touch it. Cover it and put outside for 10-14 days.
    If it has already cooled I stick them near a wind with direct sunlight but cover the tub with a black cloth.
    The black cloth will draw the sun and protect them from direct sunlight. Same applies on durations 10-14 days.
    Take the lid off and let fresh air in daily.

    After the 10-14 day period I remove the cover and rag and place in a cool area for 6-8 weeks.

    Good luck and let me know how it turns out for you.
    If you have any questions please let me know.

    Shayne

  • steve333_gw
    Original Author
    9 years ago

    I have a question on curing...

    Shayne, sounds like letting them cool off, like at night, is fine for the curing process (as long as it doesn't get too cold, whatever temp that is). Any idea how hot does it get in your black cloth covered container during the days in the sun? Just wondering what the "acceptable" temp range is and the ideal here.

    TIA

  • shayneca25
    9 years ago

    Steve,

    Good question

    It gets about 78-82 in the container when I set it in the window.
    I should note that the sun hits that window for about 4 hours a day.

    When outside they are on the porch there is no direct light. I it gets below 70 I bring them inside.

    The ideal curing environment is 80F degrees and 80% humidity for 10 days. I do a little longer since the temp fluctuates

    Keep in mind most of the starch to sugar proccess takes place when you let them sit for 2 months.

    The 10-14 days is when most of the healing takes place. Any scratches heal during this time.
    Shayne.

  • vgkg Z-7 Va
    9 years ago

    "As a side note, once I dug up the main rows I left intact the trailing vines which re-rooted and now I may have more out there to possibly harvest before first frost. Will wait and see if this is true or not. Be nice to get a 2nd crop even if they are smaller."

    Just to update my quote above - Today I dug up those leftover runners from my harvest on Sept 1st and I did get a good 2nd crop after 2 months of decent weather. I est that this 2nd digging was about 40% of the 1st harvest, not bad for just letting them run wild. Half of them are bakers and half are smaller for yam dishes. Next year I may do the same but prep the nearby soil for better re-rooting head start. Hope you all had a good crop!.

  • jctsai8b
    9 years ago

    shayneca25,

    How do you cook sweet potato leaves?

    http://forums.gardenweb.com/forums/load/asianveg/msg0717221413726.html?14

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