Let's be clear though - New Zealand Yams are delicious, the plant very attractive when healthy and the tubers also visually appealing, glowing pink grubs which look startling emerging from the soil at harvest. So I have worked out a simple but cunning cultural practice to have a good harvest while minimising the space they occupy, well at least the amount of time that they occupy this space.
It goes like this: Oca strikes easily from cuttings. As a result you can devote a small area to "stock'' or "mother" plants in the spring, planting if need be only two or three tubers which form plants that will later become the source of cutting material. These plants can grow if necessary in a fairly obscure parts of your garden, under the eaves of the house in my case.
You now wait for space to become available in your garden from mid to late summer as early crops finish eg. some early beans, potatoes, lettuce, old brassicas etc . Then when this space is cleared you take cuttings from your Oca mother plants and simply plonk them in. The cuttings will strike quickly and these will become robust plants within weeks ready to enjoy the mild autumn weather which Oca adores. I have had great success doing this with cuttings taken from mid January through to mid February (the equivalent of mid-July through mid-August in the northern hemisphere). For two years in a row I have prepared Oca in this way at the Burnley nursery in pots, ready for my students to plant them in their vegetable plots when classes commence in the first week of March. I'll post some pics of some of this year's student crop next week.
|spring planted stock plants|
|single cutting planted March 15|
|cuttings planted out|
|cuttings by May 24 - 10 weeks on|
|Tubers on March 15 cuttings, harvested May 24|
|Stock plants May 24|
|Stock plant tubers May 24|