Kumara loves the warmth – all the way through the growing process, from the shoots through planting to storage. Steer clear of cold, and keep warm in the forefront of your mind and you wont go wrong.
Those of you on light, free draining soil are on a win – your soil holds warmth for longer, giving you more lee way when it comes to harvest. Not so for those of us on clay, especially when combined with rapidly cooling soil temperatures. When left in heavy cold soils, kumara develop blemishes in storage that rot. If heavy soils and cooling temps are your lot, be on guard and ready to harvest.
Either way, at the very latest be sure to get your crop up before frosts, as frost will turn them mushy.
Three things come together to let you know kumara harvest is nigh.
- Time. Kumara are ready 120 – 150 days after planting.
- Tuber size. Scrounge around in the soil and feel them.
- Climate. Before the first frost, before soils dive below 13°C and dry, sunny weather for harvest.
Harvest
Choose a lovely sunny day, preferably having had a few dry days prior.
Cut off all the foliage with hedge clippers and add it onto the compost, or use it to mulch the bed with after you’ve gotten the crop up. Kumara greens are edible, by the way – they taste like spinach. Your cow or goat will love them too.
Slide your fork or better yet forksta in, to gently loosen the soil, then get in with your hands and scrape the dirt away with to reveal the nest of tubers.
Kumara snuggle their fragile ends into the hard stuff making them a bhuddist act to get out if you are on heavy soils. Follow their twists and turns carefully to extract them whole if you can. Be ever so careful here, they break easily, and broken ones have no storage capabilities.
Once they are up out of the ground, transfer them gently to the wheelbarrow and bring them to wherever the curing will take place.
Cure
Curing is important – it hardens the skins, sealing in moisture and keeping out damaging bacteria and fungi. It also brings out the sugars which is why you don’t get too excited about eating a freshly harvested kumara – they’re more starchy at this stage than sweet.
Lay them in a single layer, on wire racks or in baskets. Somewhere warm, with good airflow. I set my homemade, wire racks on top of saw horses, on our deck. Kumara cure well here under cover, out of direct light, bathing in the reflected heat from the concrete below. Leave them here for about 5 days.
Its likely you’ll have plenty of thin, little tubers. These go soft pretty quickly, so either gobble them up in a stirfry (sod all flavour, but just for the fun of it!) or give them to stock – pigs are ever grateful.
Store
Brush off the worst of the dirt (whatever you do, dont wash them!) and proudly lay them in a basket or box, with newspaper between each layer. Put the broken ones on top, to ensure you use them first.
Successful storage is once again, about warmth. Choose somewhere out of direct light and steadily warm – ideally above 12°C. Kumara are similar to pumpkin and squash this way, so store them in the same place. A cupboard or wardrobe in a warm room, or in the hallway. When I lived up the gorge, I stored them beneath my bed because it was the warmest room in the house. Now a days, I keep them in the bottom of our pantry.
As with all stores, check through every now and then for rots. Remove the damaged one from the store to stop the rot spreading. Cut out the bad bit and cook it up for tea.
Many thanks, Kath, for all your advice about growing and harvesting kumara, both online and in your e-book. Your tips on how to lift them without (much) mishap and cure in the greenhouse are invaluable. If I could attach a photo I would show you the sort of yield we have had here in Murchison – who says you can’t grow kumara in the SI? – the largest tubers are more than a foot long. The variety is a Koanga Institute heirloom one, Tuputini, that used to be grown by SI Maori in kete bags that they could carry around and put in warm places — has a more bushy habit with the tubers (mostly) neatly grouped vertically under the plant. I will grow my own tupu from these, following your instructions!
Thanks so much Sue! It’s really helpful for others to know that its possible down south. I appreciate you taking the time to write.
nga mihi nui Kath
Thank you! I’m about to harvest my first crop and very excited. can I ask how long do kumera store for?
Much depends here Leigh – on how well cured and on how few breaks or blemishes and on how well stored they are! Really impossible to say. Usually in a home garden there isnt enough to last very long anyway but should you have a mega crop except 6 or o good months. The longest I have had kumara last is 9 months. Cheers!
my issue is I actually dont remember when I planted them as im a beginner and I thought when the tops die down , they ready , I have felt around and they seem so skinny , so are they not ready or I have just not done a great job of what they growing in?
A great question thanks! If they are skinny now Phyliss – they wont get any bigger in the cooler temps so get them up and have another go next year!
Thank you for your great tips and hints on growing in wet areas and clay ground. I am in the Waikato, just between Hamilton and Cambridge. I planted the kumara tupu from a shop in late Nov as we had a late frost this year that killed a large amount of plants, & destroyed berries so I waited. I planted in raised beds w black excellent quality topsoil. I planted about 22 tupu and got our harvest just now, 1st week of April this year (but it’s been such a wet cold summer). Tops only just started to get slightly yellow, had a huge caterpillar eating them. Got fantastic tubers down very deep, got about 10-11 kilos so at current price $10.99 kilo it’s over $100 worth. Dry, no mould spots, couple of breaks-you have to gently rock them out of the soil. Can’t wait to eat them!
Awesome Deb – best kumara you’ll ever eat! Such a good value crop.
Hi Kath,my first attempt at Kumara ,this season, was a wonderful success.I got about 15kg of assorted sizes.Largest was 1.1kg ..I gifted it to the neighbor with 3 teenage boys.
I cured them for 5 days and decided to try storing under my bed. wrapped in news paper..
When I checked them today, after 10 days, a couple I unwrapped were starting to grow.
Help,
Can I do anything to stop them growing so I can continue with storing them.
I love learning from you.
Many thanks from South Kaipara
Awesome Christine, for the crop! Such good value. The trick with long storage is to keep the kumara dormant. Warmth and moisture are what break dormancy and make it shoot. Find somewhere with good air movement, not like a breeze but not dead air either. Try places and keep moving them about until you find the spot – storage is the trickiest bit I reckon. Meantime knock the shoots off.
cheers Kath
Hi Kath, i grew some really healthy kumara plants this year, last week i rummaged around in the growth and found one nice large tuber, so i dug up the plants. Turns out across three plants (each a couple of metres long) that was my one tuber (plus one other egg-sized one). Not even the start of any others visible. Any idea what went wrong? I grow in warm, north-facing raised beds, in a good compost-seaweed-manure mix
Hey Ben – it’s pretty tricky for me to say remotely what went wrong for you, but something didnt line up somewhere along the way. Generally where tops are lush and bottom growth poor, it indicates too much nitrogen. Depends what your base soil is and where you live – did you easily get the 3.5 months of warm weather (soil at 18 degrees). Bought compost is often imbalanced – perhaps this? Manure is likely too much. Seaweed is perfect! cheers
Thanks for the reply.
I planted the slips back in Nov, and they were in raised beds up against a concrete wall, so i think nice and warm. I’m in Wellington but grow bananas in the same spot, and have a couple of 3yr old capsicum plants in the adjacent bed, very mild microclimate.
The nitrogen issue sounds more plausible. I had tomatoes growing on the wall at the back of the bed, so was fertilising that patch pretty heavily.
I’ll try a less fertile patch next year 🙂
great information thank you. I have grown kumera for years and this year waited and waited for dryish soil and only dug them last week well squished about in heavy Takapuna clay using a fiberglass pole to loosen the MUD then felt about for lumps.
I transferred them onto the lawn to dry and flaked the excess mud off carefully…… and oh hell its rained all night. you say don’t wash – well “that was taken out of my hands” .
What do you advise please.
his is a video I made recently that may be of interest to you
Bringing The Soil Into Balance
Bad luck Pete. The weather is the weather – you can only go forwards right – whats done is done. To remdiate I’d have gotten them under cover toute de suite and cured them as soon as. Heres to next year and perhaps grow them in a mound. Best K