Yams (Dioscorea Alata)

Apparently Purple Yam, Winged Yam etc. (D. Alata) is grown as a staple crop in many parts of the world.  From what I've read, it can be grown as an annual in USDA Zones 6-10.  I'm in Zone 6, and I was looking for any information about growing these in more temperate climates, (Like what kind of yield I should expect-will it be very small because of the shorter warm season than the tropics?). Does anyone have any experience with this?  Any information will be helpful.

Hi Casper!

I think if you only harvest the bulbils and leave the roots alone you can grow it as a perennial, although your harvest will be significantly less, but it's hassle as too.
I used to be in zone 6 as well about 10 years ago. Now I'm in zone 7a because of climate change.
Have you had any success growing this plant?

Casper, yams and sweet potatoes take a lot longer than you think, sometimes 10 months to a year.   They need fertilizer at different rates at different times according to your conditions.  They wouldn't do well in frozen ground, and would be very slow in almost-frozen ground.

When planting, you probably know that potatoes grow upwards, and yams and sweet potatoes grow downwards.  So setting up how you intend to grow them is important.

If you try them in large containers in a protected greenhouse you'll see that the roots are red, skinny, and go down quickly.  Then it takes months for the tubers to form.   They need consistent conditions to do well.   They are native to Asian tropics, so we need to mimic those conditions.

You want tubers to form, so don't go high on the nitrogen.  They are deep enough that the mice won't dig down that far, but gophers are at their level, which is why large containers make it easier.  Their long vines and leaves need room and make a good ground cover for suppressing some weeds.

For your situation it will be an experiment, but worth it.  They have great flavor and store pretty well.  

Anyone here from zones 6 or 7 that has had any experience, advice, successes growing true yams?