Mulch and sweet potatoes

Dear fellow Permies.
This season we’re growing sweet potatoes for the first time. We got some cuttings and they rooted and are now growing in their respective beds.
We usually cover all our beds with mulch (mostly the weeds we pull out all over the place) as we’re in a pretty dry climate. Slugs are not a problem here.
My question for the sweet potato is, wether the vines need to touch the ground to send down roots and produce tubers. Or will they find their way?
Thanks a lot

I have vines growing up the side of my house and they grow decent tubers at the base. In other areas where they grow along the ground, each node where a leaf comes off the vine is capable of sending roots down. I'd imagine if you let it go wild with putting down roots everywhere you would end up with lots of smaller sweet potatoes.

I have grown most of mine in large makeshift containers that get a lot of shade in the summer and the vines grow out in to the sun. I will often pick them up and move them to the side to cut down the grass and weeds underneath so they don't get as much of a chance to put roots down as the vines spread out. I've gotten some large sweet potatoes this way, but I haven't actually measured the yield to see which way gives more overall weight.

I'm also no expert and only grow for personal use. They grow really easy in my location where I don't have to do much to take care of them.

It depends on the cultivar.
I have some 90days to harvest ones, and they only have tubers at the base and so it doesn't matter if it is rooted or not. And the vine only has a radius of 10ft, and it winter kills in the fall. In the tropics the vine will grow 100ft and will produce tubers along the vine as it roots, and it fact, they are perennial and will stay alive year after year after the inital planting.

If you are going to water the base of the vine, then I don't think it needs root contact, esp if you don't get summer rains.

Do note that the leaves are edible, as a water spinach substitute.

Sweet potato vines will send down roots but the tubers form this way are very small. Also, it's easy to be missed at harvest. It is advised to lift up the vines regularly to discourage the adventitious roots. Or if you have a long growing season, let the vines root but sever from the mother to become independent plants.

May Lotito wrote:Sweet potato vines will send down roots but the tubers form this way are very small. Also, it's easy to be missed at harvest. It is advised to lift up the vines regularly to discourage the adventurous roots. Or if you have a long growing season, let the vines root but sever from the mother to become independent plants.

I like that idea of lifting them. Once a week will probably do?

I ask this because currently I have 800 plants in. Last year I did 400 and I did not lift any vines. The yield was still very good, and most bulkwas exactly where I planted the main stem. I found myself doing more digging, even into the aisles sometimes...usually small to medium ones further out, like already mentioned. I dont think Ill be lifting every vine, but certainly could help.

To reply to the origianl question, my aisles are woodchipped (somewhat) and I hoe the weeds in the bed and aisles, ideally every couple weeks, and use that as mulch around the plants and the exposed soil in the beds left from hoeing. I spread some grass, hay, and other weed clippings as often as I can too. After a couple months the vines will start to crowd everything else out and just a little bit of grass and weed pulling or cutting is needed from there til harvest, basically any stuff tall enuf to stick up out of the sea of green sweet potato leaves!

Ill likely let a little bit more weedy wildflowers grow here and there among them in the beds this season, but I do try and keep grasses out as much as possible.

Wow!
Thanks for all the thorough answers.
I’ll keep them on the mulch and lift them from time to time.
While we’re at it: do y’all make cuttings from the vines to propagate or from a tuber?

Benjamin Dinkel wrote:Wow!
Thanks for all the thorough answers.
I’ll keep them on the mulch and lift them from time to time.
While we’re at it: do y’all make cuttings from the vines to propagate or from a tuber?

Ive become obsesded with sweet potatoes, 5 yrs ago I knew nothing about them and tried my hand at a dozen plants and I've went all in recently...still don't know all that much about them but they grow wonderfully without much pests or fuss, who doesn't love that??

Good question on the "slips" or cuttings - so far I've got mine from another farmer who orders a bulk amount into the thousands. It seems pretty cheap this way but for sustainability reasons I'd like to move in the direction you've mentioned.

The trick would be getting the timing right, and at the scale I've evolved into growing and selling, having the right setup to get enough segments. Some hardwire mesh framed with wood just above water level in a few old bathtubs (which on a farm theres always a couple laying around picked from trash) and several dozens of 1/2 potatoes would maybe work. Id imagine 10-20 cuttings from one 1/2 of a potato? Maybe more? I have only scratched the surface of researching this, hopefully you or someone else finds out more and posts it.

Based on my experience, sweet potato vines don’t need to touch the ground to root, but they will produce better tubers where the vines make contact with the soil.

As a long-time sweet potato grower, I find it better to mulch around the original planted plants, and in wet weather to move the vines around every few days so as to prevent, as much as possible, the formation of other roots and therefore, potatoes, along the vines.  This will focus the formation of roots at the site of the original plants, and they will grow in a clump there and form nice big roots, making harvest easier and using the potatoes more rewarding... The alternative of letting the vines root as they will, particularly on bare soil, is a bunch of small roots scattered at random under the entire area of the growing vines, such that harvest means digging over the entire area, and getting a bunch of small roots.  The absolute yield per area may be larger this way, but the difficulty of harvest and size of the roots make it less rewarding.