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madonnaswimmer
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when do you harvest your sweet potatoes?

I have sweet potatoes growing in a container for the second year.

It's starting to get chilly outside, with frost advisories almost daily. I am becolming irritated with dragging this container inside every night... so I was thinking of pulling them up. I can see one rather large sweet potato poking out near the surface.

My only problem is... Last year, I seem to remember having my sweet potatoes growing outside on my balcony alongside my Halloween decorations(which I probably put outside mid-October). Am I too early?

Come to think of it, I also remember taking a photo of my sweet potato harvest last year, and I was wearing shorts in the photo.... so is it getting late?

Argh, frustrating. When do you harvest your sweet potatoes?

Ohio Tiller
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I only plant a couple plants since the wife is the only one that eats them and I dig them whenever she says she wants one. I will go out and dig one at a time as needed. I typically get enough for here sweet potato fix each year. I just dug one Saturday and I could see I had a few yet to go under that plant. I will dig the rest for thanksgiving so she can make her casserole she likes

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applestar
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Do they usualy push up like that? I don't think I noticed before -- I seem to recall digging pretty deep to find my sweet potatoes.

I've never tried robbing them... Maybe I should try 8) Do you wade under the vines and foliage to look for them? What are the potato signs besides ones actually pushing out of the ground?

Here, the forecast for last night and next two nights (maybe more -- it's impossible to get an accurate forecast for my area and I always have to guesstimate by forecasted temperature and dew point) are in the low 40's, so, yesterday, I loosely covered the sweet potato bed (and my pumpkin, watermelon, and pepper beds) with hoops and slitted plastic sheeting.

I have read that sweet potato tubers shouldn't stay in 50° or under soil temperature for long or they will start to spoil. Some websites recommend harvesting BEFORE the foliage is frost-killed, others recommend harvesting after they are frost killed. Previous years, I harvested on the day of frost warning when it was almost sure to happen (expected temp drop under 32°). This year, I'm going to let them go until the foliage dies to see what happens.

For now, forecast for the daytime highs are in mid to upper 70's so they can definitely grow some more with the extra protection in place.

Ohio Tiller
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I always grow mine in mounds just like my grandpa did. so it is a bit easier to get under them to scrape on out. I always make my wife come out and hold the plant back while I dig one up for her.

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I'm wondering when to harvest as well? we're nowhere near the threat of a frost in TX yet, so should I just leave mine in the ground til it's colder? Will they just keep growing until you pull them or until the frost is near, or do they reach a certain size and sort of plateau, for lack of a better word?

I planted them several months ago, but of course didn't write down exactly when, so I'm not sure if they're mature enough to dig up yet or not. I have a whole mess of vines that keep trying to take over my whole yeard though. :?

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TheWaterbug
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[url=https://www.sandhillpreservation.com/pages/sweetpotato_catalog.html]Sand Hill says[/url] that early varieties need ~1,200 heat units (e.g. degree-days above a basal temperature of 55*) to reach edible size.

I have a mix of varieties, and right now I'm right about 1,200 heat units since planting slips on July 19th. I'm basing this on historical average temperatures, not our actual temperatures from this year. I suppose I should try to find some data to do a more accurate calculation.

We're still in 80s and reaching 90 this weekend, and going no lower than mid-60s at night, so we're packing on 15-20 heat units per day right now. One side of my sweet potato bed is doing a lot of nothing, but the other side is a pretty good carpet of green right now. I should probably do a test dig this weekend and see if there's anything worth robbing.

* anyone know the basal temperature for basil? :D

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applestar
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What is basal temp? If it's temp at which they stop growing, I believe it's 60°F or 55°F for basil, but am not positive.

Here's a calculator. It's been over 1200 degree days since I planted the first set of slips.... 8)

https://www.weather.com/outdoors/agriculture/growing-degree-days/98201

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TheWaterbug
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applestar wrote:What is basal temp? If it's temp at which they stop growing, I believe it's 60°F or 55°F for basil, but am not positive.

Here's a calculator. It's been over 1200 degree days since I planted the first set of slips.... 8)

https://www.weather.com/outdoors/agriculture/growing-degree-days/98201
That was kind of a joke :)

But thanks for the link! I've been calculating manually with a spreadsheet; it's good to have something more automatic.

But I do wonder why the base temp is only available in 10-degree increments.

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applestar
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:lol: Oh! Now I get it.... :D

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applestar wrote::lol: Oh! Now I get it.... :D
Base temperature not herb temperature. :P

Eric

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gixxerific
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All my Basil died so that temp was way up I'm surprised anything else survived. :P :wink:

As far as my Basal temp mine were done months ago. We had something like 20+ stragiht OVER 100. That easily 1000 right there.

Last year we can't go by. It was weird at least here and most everywhere else. Winter came very late if it came at all. The old farmers say it's gonna be wet and cold this year. So be prepared I will be pulling soon. I have 2 beds so one will more than likely get pulled sooner than the other.

Really they are heat lovers so in the weather I have been having lately I don't see them growing much at all from here on.

You don't want to harvest after a bunch of rain, they should dry out for a bit first.

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applestar
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But I do wonder why the base temp is only available in 10-degree increments.
I think it's because as in most cases, people who design these things don't actually do the things they are for. Otherwise, it wold be obvious that 10° increments is totally inadequate.

I used the warmer temp. But fiddling with beginning date of the time frame and ending date of the time frame, you get totally different results (stands to reason) -- but it kind of illustrates the importance of paying a bit more attention to when you should start planting the longer maturity crops -- Especialy in shorter growing season areas.

I think next year, I'll start planting them earlier in warmed bed and low tunnel. Did I share the Japanese webpage I found in which a Japanese sweet potato farmer compared growth rates from using two different methods from two different years in a photoblog?

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soil
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Link to Japanese thing please applestar

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applestar
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Sure. :D
This is the page I was remembering. He was actually comparing two methods he used in '08 and '09 to grow slips.

In ’08 he grew them in a high tunnel. In '09 he grew them in a manure activated hotbed AND put up a lw tunnel INSIDE the same high tunnel.

https://www.geocities.jp/imo8007/tukuri/kako/satumaimonh0809

He also compared growing the potatoes in the fields with and without black plastic mulch

https://www.geocities.jp/imo8007/tukuri/satumaimo/satumaimom
https://www.geocities.jp/imo8007/tukuri/kako/satumaimom0809
https://www.geocities.jp/imo8007/tukuri/kako/satumaimom0910

https://www.geocities.jp/imo8007/tukuri/satumaimo/satumaimo
https://www.geocities.jp/imo8007/tukuri/kako/satumaimo0809
https://www.geocities.jp/imo8007/tukuri/kako/satumaimo0910

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TheWaterbug
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Here's my sweet potato bed:

Image

No flowers yet, but I do have a lot of vine. Curiously, the plants at the far end seemed to be the most vigorous right after planting, but now they're lagging far behind.

I don't know if it's the location or the variety, as I planted 3 different types-- Korean Purple at the far end, Purple Delight in the middle, and Caro Gold closest to where I'm standing.

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rainbowgardener
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Very pretty! I like the carpet of heart shaped leaves. All the plants closest to the fence seem to be a bit stunted, the far end and the left side. I would assume that's because they are shaded more by the solid fence.

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applestar
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If I remember correctly Korean purple has a long maturity date. Those are dark red-violet skinned dry yellow fleshed ones right?

My eyes actually immediately went to the pineapple plant. :D
Did you grow that from the top of a pineapple? I just dug up, potted up and brought inside two of mine -- last to come inside because they had been planted in the ground this season. They each had a sizeable pup that were no more than a nubbin in spring, so they came in as 4 plants.... Now I have 6 :roll:

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TheWaterbug
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rainbowgardener wrote:Very pretty! I like the carpet of heart shaped leaves. All the plants closest to the fence seem to be a bit stunted, the far end and the left side. I would assume that's because they are shaded more by the solid fence.
Yeah, I'm not really sure what's going on. That's a concrete block wall at the end/left, and it gets pretty much full sun for most of the day. I'm standing facing NE as I took this picture.

My Australian uncle is in town this week, and he was telling me last night about his garden and his sweet potato bed. He says he likes to eat the leaves. I haven't tried that yet, but I've clearly got enough to go around, so I may pick a bunch this weekend.

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TheWaterbug
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applestar wrote:If I remember correctly Korean purple has a long maturity date. Those are dark red-violet skinned dry yellow fleshed ones right?
[url=https://www.sandhillpreservation.com/catalog/sweet_potatoes.html]Sandhill says[/url] KP is supposed to be early, so I guess mine are late ;)

Caro Gold is also supposed to be early, and Purple Delight is not listed in their catalog.

But the PDs were a substitute for Yala, which is listed as late.

So my entire bed is growing backwards :P
My eyes actually immediately went to the pineapple plant. :D
Did you grow that from the top of a pineapple? I just dug up, potted up and brought inside two of mine -- last to come inside because they had been planted in the ground this season. They each had a sizeable pup that were no more than a nubbin in spring, so they came in as 4 plants.... Now I have 6 :roll:
Yes! [url=https://www.helpfulgardener.com/forum/viewtopic.php?p=258408#258408]I started 3 in water back in May-ish[/url], and only one ever rooted.

I think I put that one in soil right around the time I planted the sweet potato slips, or around mid-July. It's sitting amidst my sweet potatoes because they're inside a rectangle of bird netting, and something was digging into my pineapple when I left it outside. With such shallow roots I thought the squirrel (or whoever) was going to rip it out and take it away.

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applestar
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My sweet potato jungles, hoping boosting the heat index under the vented plastic will help:
[img]https://i290.photobucket.com/albums/ll272/applesbucket/642F65EF-204E-4055-95EB-5A9BBA362A21-32986-000017DD788BFCDE.jpg[/img]
[img]https://i290.photobucket.com/albums/ll272/applesbucket/712699B0-5257-48F3-BC24-DBB2B8B46F94-32986-000017DD81F2844C.jpg[/img]
Seminole pumpkin vines are growing along the left and are also semi-covered, but I saw some powdery mildew spots starting on them this morning after overnight muggy rain. :?

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Gary350
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Wait until cold weather kills the vines to harvest the sweet potatoes.

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TheWaterbug
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Gary350 wrote:Wait until cold weather kills the vines to harvest the sweet potatoes.
What about in warm climes where there is no cold weather?

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TheWaterbug
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Hmm. There's not much going on down there. Saturday was Day 86 since planting the slips, and I've got a nice carpet o' green vines going on, so I did some digging:

Image

I'm digging down about a foot into my double-dug soil, and there's just these tiny little roots.

We got plenty of hot weather this year, and I watered pretty generously at the beginning, but then I backed off quite a bit later, as I didn't want it to get soggy down there. I applied some Liquinox Grow 10-10-5 a few times early, but nothing in the last 6 weeks.

I'm well beyond the 1,200 heat units suggested for sweet potatoes, as "normal" temperatures would put me at about 1,400 right now, but this summer has been unusually hot. Should I just wait longer and start watering again?

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Gary350
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I plant sweet potatoes about 1st day of April. Frost kills them about last week of Oct. That is 7 months of growing. The mother plant makes the largest potatoes. Every place the vine sprouts roots satellite potates are not as large. I often get 110 lbs of potatoes from 3 or 4 plants. Sweet potatoes like it hot and dry and they don't seen to care if the soil is good or poor. They need full sun too.
Last edited by Gary350 on Fri Oct 19, 2012 11:35 pm, edited 2 times in total.

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TheWaterbug
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Thanks! Based on that I'm going let them sit until at least Thanksgiving :)

How much do you water them?

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Gary350
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TheWaterbug wrote:Thanks! Based on that I'm going let them sit until at least Thanksgiving :)

How much do you water them?
I don't water my plants we get 300 days of rain here in TN on average every year.

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well I'll be.... I decided I'd pull up my vines because the weather's been flirting with the low 40's/high 30's on the coldest nights the last few days and my leaves were starting to turn. all season long, I'd been sticking my hand in the dirt poking around and only found one small (about an inch in diameter) sweet potato so I thought the whole effort would be a dud.

little did I know....
[img]https://i46.tinypic.com/a5hsh1.jpg[/img]
I'd pull up all of these!

I started this with one store bought potato, and planted three slips when they were about 6 inches long, all in a 4x4 bed which was already growing an herb and japanese eggplants. the sweet potatoes were sort of an afterthought. this is my first year gardening and I'm just so excited now! great way to end my first season :)

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TheWaterbug
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Ooooooh. I'm hoping for a similar surprise. Because right now it's not looking so good :(

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it was truly a surprise! fingers crossed your garden will do the same for you. It's just a very small backyard garden I started for fun but I'm thrilled with the results - can't wait to expand and try to do bigger and better next year - maybe I can grow enough taters to share with all the neighbors on my cul de sac next time around :)

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TheWaterbug wrote:Hmm. There's not much going on down there. Saturday [October 13] was Day 86 since planting the slips, and I've got a nice carpet o' green vines going on, so I did some digging . . . . I'm digging down about a foot into my double-dug soil, and there's just these tiny little roots.
I'd completely ignored these in the ~10 weeks since then, and today I pulled up two of the plants to see if anything had happened:

Image

They're not huge, but they look edible. But they're also cracked everywhere, and several of them are heavily veined. If my notes are correct, these are Caro Golds, and this is what I got from two plants.

The soil is still nice and loose; I pretty much just pulled up on the plant (which is still green and thriving in our 60+ degree December) and the sweets just came with it. I put the plant back in the ground along with the few remaining roots; I wonder if it will keep growing.

I turned off the automatic watering back in October, because we've had more than average rain this year.

So I'm psyched up to eat these tonight. If they're good I'll dig up a bunch more tomorrow.

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WOW! You have a very precise method for calculating when potatoes are ready. I use a much less sophisticated method. Sweet potatoes are supposed to be ready 130-170 days after planting. I mark 150 days on my garden calendar to check them, and I put a label in the pot with the planting date and expected date of maturity. As it turns out everything here takes a lot longer then what is expected. I dig into the container and feel the size of the potatoes. If they seem about right I pull them up. Since we don't get a winter here, the vines will not die down, so that is not a reliable sign. Sweet potatoes can be invasive, so it works better to keep them in large containers. It also makes it easier to harvest since I have hard clay soil. Thankfully, I don't have to move the containers much.
If I plant the right varieties, I can also eat the leaves :roll:

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TheWaterbug
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TheWaterbug wrote:So I'm psyched up to eat these tonight. If they're good I'll dig up a bunch more tomorrow.
Well, they were terrible. After I put them in the oven, I read up on these guys, and evidently they don't really get sweet until they've sat for a month or two.

But I also wanted to clear out the space, so I dug up the whole patch. And got maybe 15 lbs. of sweet potatoes. :roll:

Some of the plants had nothing at all, others had tubers too small to eat, and a handful of plants had 2-3 good-sized 'taters. But nearly all of them were heavily split.

I've got them sitting in a storage room; I'll try eating a few in a month or so to see if they've improved.

So clearly I'm doing something massively wrong, since sweet potatoes are supposed to be easy to grow!! I think my soil prep was OK, because the soil will still really loose when I harvested. I may not have watered enough during the hottest part of late summer.

I'm going to try again this year, and I'll from a different slip vendor so I can start earlier.

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I'm sorry to hear that. I don't know what varieties you grew. I only grow the ones that do well in Hawaii and that I like. Sweet potatoes don't need a whole lot of water but they will dry out if they don't get enough. The soil cannot be too hard or the potatoes will not be uniform and not so easy to dig out. Drought stressed potatoes go deeper. Here it is kind of moot. It rains nearly every day for a short time and the humidity is high so the soil is warm and does not readily dry out. Sweet potatoes are wild and that's why I contain them in a pot, they take over. The sweet potato that is the most popular for eating here is actually pretty dry. It is called Okinawan sweet potato. The flesh is purple, firm, and on the dry side. Yams are actually sweet potaotoes that are softer, sweeter, and more moist than hard sweet potatoes. Maybe you did not really do anything wrong. Try planting a soft sweet potato variety. They would be called yams in the U.S. like Garnet or Jewel. True yams are not sweet they are starchy and are planted by tubers. Sweet potatoes are sweet but the flesh can be hard (dry) or soft and moist depending on the variety you select
Root splitting and oversized roots are usually a sign that they have been in the ground too long.

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Gary350
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Try a few different types of sweet potatoes next year. Try some experements too, till in some organic material then plant potatoes there and see what happens. You also need 12 hours of full sun. The potato crop is directly related to how much full sun it gets.

I was reading online once about different types of potatoes. As I recall there are about 200 different type of potatoes. Some potatoe grow best in cool weather while others do better in hotter weather. In TN I could never grow white Idaho or Russet potatoes larger than a golf ball. Red pontiac potatoes did much better they like hotter weather. Sweet potatoes from the grocery store did great in my garden as long as they got full sun. The new house we moved to in 1991 had no trees in the new subdivision so every thing in the garden did great but 20 years later when trees were 35 ft tall and made lots of shade it was very hard for me to get good sweep potatoes. I moved to a different house for 2 years with 3/4 acre of land the sweep potatoes loved it there full sun all day until 7 pm.



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