Yams, like other tubers, need a long warm growing season. They will take approximately 14 weeks to mature.
When To Plant
Yams do not tolerate frosts or mature well in cold temperatures so plant sprouted Yams as soon as the threat of frost has gone. This tends to be around mid Spring. If you are growing your Yams from tubers left in the soil from last season, just leave them to overwinter underground and they will pop up of their own accord once the weather warms up.
Yams produce lots of small tubers underground, varying in size from a pea (not worth harvesting) to the size of a large fat thumb. The plants above ground have much more on top that what’s going on below and can cover quite a large area.
Yams like to be grown in an open, free draining soil in full sun. You will get the best Yams by providing plenty of water, particularly when the Yams are fattening up just before harvest time. If you have heavy soil, just be careful not to water log them.
Yams don’t require a lot of maintenance and many gardeners find that they just keep coming back each Summer with barely a thought.
The only consideration is keeping this plant in the area you want it to grow as it does like to spread a little if it can.
Yams should be harvested when the tops of the plant go yellow and start to die off. In colder climates, harvest is often delayed until after 2-3 good hard frosts which kill off the tops of the plants. It is thought this makes for a bigger, better Yam.
Yams should be stored in a cool, dry and dark spot so that they don’t sprout. They store quite well and should survive a good few months this way.