The saying is that kūmara needs to be harvested before the first frost, so you will find that where you live will determine harvest time.
Kūmara takes about 100-120 days from planting to maturity, and you will start to see the leaves become slightly yellow.
This is a sure sign that your kūmara are ready to be harvested.
I know a lot of gardeners who choose not to grow kūmara because they find storing them a headache.
Talking to friends who grow kūmara, they all had different methods of storing them over the winter, but I learnt some of the things to watch out for.
The first is to harvest your crop before the frosts.
If left in the ground, the frosts will mush your kūmara.
They like to be stored in a well-ventilated and dark spot, and while they love the warm soil when growing, they are not so keen on humidity when they are harvested, as this will cause them to rot.
Harvesting
Choose a nice sunny day, preferably when the soil is not wet from rain.
Remove all the leaves with some hedge clippers and make sure you compost those leaves, mulch them, or if you have a pet goat or sheep, they will be delighted to receive them too.
You can also use the tops in soups or salads, stews, or cooked like spinach.
The kūmara needs careful extraction with a garden fork.
Any stabbed with your fork or snapped in half will be no good for storage.
The curing process
This is the process of hardening the skins and sealing them to keep in moisture, but keep out the bad fungi and bacteria.
This also brings out more sugars, which gives kūmara that delightful taste.
At this early stage, they are very much starch.
They need to cure for about five days.
I have a friend who spreads his on paper around his wood burner, and another who has an old wire bed frame under the eaves of his workshop.
He places his kūmara out of direct sunlight and covers it with newspaper.
The heat from the concrete helps with curing.
Both told me they only store the good-sized kūmara, and they eat the small tubers first.
Storage
Don’t wash them, just give them a gentle brush, removing the bulk of the soil.
They love to be wrapped in newspaper (like a little comfort blanket), and stored in an old wooden box is ideal.
Successful storage is about warmth, not humidity.
Keep them out of direct light; a box in your pantry is fine, so long as it is about 12 degrees at least.
Or even your garage window or outside shed, just so long as they are not in direct sunlight, but warm and shaded.
You need to check them regularly, as one bad kūmara will find the rest!
Rodents
Don’t try storing in cardboard boxes, especially in a shed or garage.
The rodents, especially rats, will also think you have left a picnic hamper out for them.
In the past, I have used untreated ply boxes, and if stacking, you will need a top lid.
I have also used adapted wine pine boxes and some wooden food hamper boxes I managed to procure.
Next year’s seed kūmara
Select the absolute best tubers from this year’s crop, they need to be a decent size, undamaged and unblemished.
Wrap, label (variety) and store in one of your boxes.
Get out your maker pen and write DO NOT EAT on the box, and you will be set for next season’s crop.
A good idea is to rotate your kūmara crops yearly, planting a winter cover crop in the patch you have just harvested, like mustard seed or the like.
Nothing beats a roasted or stuffed kūmara, this is a crop well worth giving a go.