Saturday, May 24, 2014

Oca or New Zealand Yam harvest - how effective were late season cuttings?

Oca tubers start shooting in late October in Melbourne which is springtime. But as I've explained before they are short day plants which means that their tubers don't begin to form until after the autumn equinox, around March 21. It then takes another 6-8 weeks for decent sized tubers to form. This means that from the moment you plant the tubers you are waiting around 9 months for a crop which is quite a long time to have space occupied by a crop doing 'nothing'. You also need a frost free autumn to have a successful crop. That's not a problem where I am, especially with a record breaking mild May at the moment but frustrating for those where frosts come early or unpredictably.

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
This year at home I wanted to see just how late I could strike cuttings and still get some kind of crop. So I took cuttings and planted them on March 15, the middle of the first month of autumn here and only a week before equinox when Oca stems begin forming forming stolons and tubers. This I thought might be pushing the envelope but the photos below show that these late season cuttings have produced decent tubers from very little original plant material and in a small area. This has no doubt been helped by a record breaking warm to mild autumn but I still think it proves the point that you don't need vast areas of spring planted Oca to enjoy this crop - just grow a few initially and take cuttings later. Truthfully, I've also planted tubers in between vigorous tomato plants where they spent months being shaded out and now with the tomato plants gone the Oca have come into their own. In other words, they're quite happy to grow sub-optimally for months while they wait for the good times to arrive.

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

Sunday, May 18, 2014

Eating perennial nettle

I grow the perennial nettle Urtica dioica. I have one plant sprawling behind one of my Taro groups under a small plum tree and another plant down the side of the house. Both are in shade most of the time. With the heat of summer long gone and with good rain in April, these nettle plants have come alive. Several years ago one of my students told me that annual nettle Urtica urens really was as good as spinach. This species was growing abundantly in the student veggie plots at Burnley's field station and so I took some home for a trial. I was blown away by its texture and flavour - it was as good as or better than spinach.

There are two obvious points to consider when using nettle species. One is that you wear gloves when harvesting, preferably gloves that cover most of your wrist as well as your hand, and second, that you must steam or boil the leaves to eradicate the stings (the fine hairs on the leaves). If you do these two things then nettles are worth growing and are absolutely delicious. The photos below show the big perennial nettle plant under the elephant ear of the Taro, harvesting with gloves, preparation and then the final cooked product (alongside choko, sweet potato, and literally the last fresh beans and zucchini from the garden for the 2013-14 growing season).

Enset(e) Abyssinian Banana - growth over summer

My Abyssinian Banana is enjoying Melbourne's late autumn mildness and warmth. It survived a nightmarish heatwave in January and hasn't looked back. The shots below show its growth since November of last year. I've got hold of three small ones in 20cm pots and may plant one more of these in garden. What I'd really like to do, perhaps in someone else's garden, is grow a grove of Abyssinian Banana and then prepare the corm or stem for eating in a few years' time. Here's two great Youtube videos on how important this plant is in the Gedeo region of Ethiopia -

November 2013


May 14

Friday, May 2, 2014

Red Sweet Potato - Northern Star

I love the golden sweet potato, the Beauregard variety, which now dominates supermarkets here in Australia,. It's very easy to grow and yields well. It's classified as a type of 'moist' sweet potato and to my taste it's like a denser, sweeter blue-type pumpkin. But this year I have grown the red skinned type, a 'dry' sweet potato with white flesh and it's a revelation taste-wise. It's starchier with a subtle sweetness and it's now my favourite sweet potato from the drastically limited selection we have available here (that limitation being strange and frustrating given that our nearest neighbours in Papua New Guinea have hundreds if not thousands of cultivars). Here's some photos of my red-skinned sweet potato crop which I think is called Northern Star. Next year I'm growing to plant more of these.

Choko or Chayote crop

So it's official - I have finally produced a good Choko crop and better still I have convinced others that they taste great and deserve to be more than a survival food. I don't know about the rest of the world but in Australia, especially it seems for people who grew up along the NSW coast, Choko is a by-word for hellish gluts and bland servings of the same vegetable night after night. This seems to affect people in some broad age range of 50-80...seriously, there is a whole group of Choko-traumatised New South Welshpersons out there. I blame the Anglo-Saxon culinary limitations of Australia during the 1950s and 60s for this because Chokos are popular with the Vietnamese community and their food is far removed from barbaric stodginess. Anyway, after some failure over recent years I have now found a nameless variety of Choko via Karen Sutherland which thrives in Melbourne and which is still flowering in the increasingly gloomy and mild to cold weather of early May. Here are photos of this pear-shaped wonder. The secret I think is to pick them at a medium size rather than wait for them to get too big.

Choko hanging off the foliage of a Tree Dahlia