yams

[Denise]

I planted yams out of my fridge back in October and now have very happy plants. I am wondering if I should mound them up like potatoes to increase the yield? However, I am worried about breaking their stalks - they look reasonably fragile and I dont want to introduce disease...your thoughts? also any tips on when to harvest would be great! thanks :)

[Robyn Wolfe]

Hello! I would plant them not too deep in good soil about 4-6'' and very firmly press down the soil. For me they work better like that than in loose soil. I'll be interested to see other answers. Harvest when the foliage has died completely. Good luck

[thegardener007]

Is this a type of Discorea sp. I ask because some people confuse yams and sweet potatoes.

We had Discorea purpurea (you'd never guess it is called purple yam) growing and it produced an abundant crop by being left in the ground for three years without being touched.

When we dug it up there were yams about 70-80cm long and about 15-20cm diameter. Huge things. The entire clump would have been an easy meter in diameter. It took some digging to get them out.

I think mounding would work just fine. I've seen yams produce off the vine where it has been suspended in moist air. I think mounding dirt will give you more yams near the surface and easier to harvest. You could probably just use mulch and keep it moist. The stems look fragile but in due course they are tough as leather. You could hang your... never mind.

I'd love to have a yam if you get any spare. Haven't seen them for ages. Do you know which one it is?

[Tracey Ellery]

Hi Denise :-)
We must chat sometime.
I've got yams in for the first time this year and I mounded mine like potatoes 4 times. I"m expecting good things and have been told to dig them in winter - they take a long time to grow.

[Denise]

thanks all, I don't know the official name for these ones - they are a combination of the red and yellow little gnarly ones I buy from my organic supplier. I believe we call them yams but they are not realy so they could be sweet potatoes. All I know is that they are yummy!

Decision made: I am going to mound this evening and if I have any spare from a winter harvest I will let you know!

Tracey, lets work out a good time for a chat, hope all is well :)

[Richard Watson]

Discorea purpurea are what's called Chinese yam but are not the same yam as we in NZ call them,there's so much confusion round the name yam.In Asia the sweet yam is what we call the Kumara, in other areas sweet potato is also the Kumara.
The yam in NZ is called Oca in most other places around the world,the name originally coming from South America.

Yams don't need to be mounded like a potato as they develop there tubers deep enough that they don't become exposed,myself,i have found that the ones closest to the surface can be effected by heavy frosts in the middle of winter,because i leave mine in the garden and dig when needed.The one thing i have found myself is i have to keep the yams plants alive till at least the 1st of June to get a good crop as its when day light hours become 12/12, light/darkness is what triggers tuber development.
I'm going to cover mine this year in clear plastic using hoops to increase the warmth in April and see if this helps me further.

[Dinzie]

True Yams are from the oxalis family and look like a large version of the common oxalys in the gardens ... .It is not a vine ... If it's vining it is a Kumera

You can mound them up but this should be done as they grow when they have the chance to form roots ... If left the stems mature and you won't get much additional harvest ...

They are a long maturing crop and will need well into the autumn to produce enough tubers ,,,They are also heat lovers .....frost will kill them outright obouve the ground .. .

D

[Denise]

thanks again everyone. These look like a pretty oxalis (definitely not kumara) and are sprawling with a diameter of about 40cm so I guess I have missed the time to mound them, although I might try with some of the smaller plants and compare. If they are frosted do the tubers survive? I wonder if they would overwinter under a layer of mulch and then produce a better crop next winter?

[Richard Watson]

Where i am in inland North Canterbury We get -8 every winter and find the frost gets down about 3-4 cm and will kill any within that layer,i dont but a layer of mulch would help stop that.
Before i said you don't need to mound them,thats fine for me as i have lots of space,but on a small area i could see the advantages of doing so.Its the same with potatoes too ,"if you cant go outwards,go upwards

[Dinzie]

no don't leave them in the ground ..too risky - plus you will not give them the space they need to produce the next year .......

D

[Richard Watson]

How do you mean Dinzie by "too risky" and also want do you mean by "plus you will not give them the space they need to produce the next year"
Are you saying that you grow them in the same ground the following season??

[Hester]

I grew yams (oka) last year and found them really easy in our local climate. I just basically buried them in a garden plot and left them alone. I occasionally weeded them. They were not the best specimens when I planted them, as I kept forgetting about the tubers I had stored to plant, and they were old-but they still grew pretty well.I haven't had any problem with them being invasive but I only grew a few. This year I forgot to plant my tubers again. So I guess I'll keep them until next year. Or maybe just put them in the ground to overwinter. It would be interesting to see how they survive.
I have a photo and a bit more info. on the blog I wrote when I dug them up.
http://ooooby.ning.com/profiles/blogs/nz-yamsoka

[Richard Watson]

Hester, just to let others know the international spelling of what we call in NZ "Yam" can be either "oka"or "oca"