Something a little unusual to grow in our greenhouses – the NZ yam. These are a very tasty tuber, unknown to most Australians.
Having lived in Australia for 16 years after moving from New Zealand – I’m always keen to get hold of commonly grown NZ fruits and veggies that are hard to find here in Adelaide. I have fejoas and banana passionfruit that are okay with the light frost we get here – but what about NZ yams or Oca as they are also known as?
People that haven’t tried them before probably think they are a potato/taro type of vegetable – but they are not. In fact, it’s good to expose them to the sun for a few days after harvesting to increase the sweetness level (unlike potatoes that turn green and poisonous). They range in size, the average being about 4-5cm long and 2cm wide – like fat squat fingers and have a slight lemony taste. They can be used raw in salads, steamed or best of all (in my opinion) roasted! They don’t need to be peeled and become slight chewy on the outside and soft on the inside.
The plant itself disconcertingly, looks a lot like the soursobs! Although, they are in the same family – you won’t have any problems with them spreading out of control. In New Zealand and other cooler places like Tasmania, yams are grown over the Spring and Summer to be harvested in Autumn/Winter. Unfortunately, yams really dislike days when the temp gets into the mid 30’s. So to beat that problem, I tried the following….
I ordered my yams off the internet from Tasmania in August. I then stored them in a container with a tight plastic lid in the crisper section of my fridge. They stayed there until I planted them out in the beginning of March. As frost will kill off the foliage of yams (we get frost we I live) I planted them into the green house. The tubers had sprouted a little in the plastic container, so I had to be careful not to knock the sprouts off when I put them into the ground. I placed them about 10cm deep in soil that I had added complete garden fertiliser to. Within a couple of weeks the leaves were appearing above the ground. I mounded the soil up around them to encourage tubers to form higher up the stems. The plants grow to about 30cm high and wide which is perfect for the dripper watering system I use in the greenhouse. They seemed resistant to a lot of diseases and pests.
By the end of June my plants had pretty much died down, although I didn’t dig them up until 2 weeks later. I was thrilled to find lots of yams underneath the soil. There were both the pink and yellow varieties. I found that the largest yams planted had the best yields. I did notice that a lot of the yams were on the small side 2-3cm instead of 4-5cm. But the after having a meal of them, it was decided that the smaller ones tasted better! I kept the largest ones aside to keep in the fridge and plant out next year. Without a greenhouse this wouldn’t have been a possibility for me. I’m actually hoping to buy another greenhouse to dedicate to them, as they don’t like growing where the potato family has grown before (including tomatoes). Some may question the fiddling around with storing, etc in order to grow these vegetables – but a lot of Kiwis in Australia would love to get their hands on some yams!
Landera is currently having a sale on our greenhouses and greenhouse accessories, we recommend the Silverline 6×8 to have a try at growing your own yams, if you wanted something cheaper there is always the double cold frame which can be moved and is good for smaller spaces.
Definitely, worth a try!