Growing Sweet Potato, also Kumara

Ipomoea batatas : Convolvulaceae / the morning glory family

Jan F M A M J J A S O N Dec

Not recommended for growing in USA - Zone 5a regions

  • Plant shoots or cuttings (Slips). Best planted at soil temperatures between 63°F and 95°F. (Show °C/cm)
  • Space plants: 16 - 24 inches apart
  • Harvest in 15-17 weeks.
  • Compatible with (can grow beside): Best in Separate bed
  • New shoots on Kumara
  • Well grown Kumara

Sweet Potatoes require a long warm growing season. Plant in free draining loose soil. Fertilise before planting but no more when the plants are growing as it will encourage vine growth. They will go for miles and you will get no tubers. If they do start spreading, lift the vines off the ground to prevent them rooting.

Mound up the soil about 20 cm (8 in) before planting. Let the plants die down, (leaves die or turn yellow) before harvesting the tubers. Dry them in the sun for a few days. then store in a cool dry place for up to five months.

Culinary hints - cooking and eating Sweet Potato

Use mashed, boiled, roasted, baked or fried. Or use in soups, pies, casseroles, curries and salads.

Your comments and tips

17 Mar 11, Kim Davies (USA - Zone 5a climate)
I ate kumara everyday when visiting NZ and loved it! Because it was less sweet than USA sweet potatoes. I am craving it and need to find out how and if I can get seeds and grow it in Virginia? Would love your help on this!
18 Nov 11, graham (USA - Zone 5a climate)
I would like to try to grow kumara potatoes in our green house as you say they need a long growing season. Can you advise me where I can buy tubers/seeds? Many thanks Graham
26 Jun 18, timothy (USA - Zone 5b climate)
I get my slips from Pioneer Garden and Seed in Villa Park IL. I grew sweet potatoes for two summers with great harvests. I am not sure why they say 5b is not good for sweet potatoes.
02 Jan 12, Lisa Baird (USA - Zone 6a climate)
I also long for NZ Kumara, and have been unable to find them in the states. Where can I order tubers for growing or for eating? I'll start a greenhouse if needed. Thank you.
21 Mar 12, Malina Beatrice (USA - Zone 10a climate)
I found Kumara at Whole Foods in Encino, but they had them labeled "Japanese Sweet Potato." If I hadn't just seen them on a trip to NZ, I never would have known! Hope it helps.
16 May 15, Carole Hanley (USA - Zone 10b climate)
I would like to grow these wonderful sweet potato here in Nevada. We ate them in New Zealand and they are beyond good.
24 Mar 17, Bob (USA - Zone 9b climate)
Trying to find some Evangeline sweet potato slips. I've only been able to find commercial quantities. Any help appreciated
24 Mar 17, John (Australia - temperate climate)
'Evangeline' was developed at a horticultural research institute in Louisiana and has Intellectual Property Rights. This means that it could only be available to commercial growers who probably pay a royalty for the slips for their crops. You could try the Sweet Potato Research Station at: PO Box 120, Chase LA 71324. These restrictions seem onerous for home gardeners but help pay for the development costs for new varieties. Try them, they may be willing to send you a few slips.
27 Dec 20, Rick (USA - Zone 9b climate)
Bob, I had the same problem so I ordered a couple of sweet potato's from Walmart. I tried to grow them on my counter to no avail. I went on YouTube and found out that stores buy potato's that have been sprayed to prevent sprouts. Best if you buy your potatoes from a farmers market. Wash them, then cut them in half. Plant the half's in a good compost and keep moist. You should see slips growing out of your potatoes in a few weeks. I found it time consuming but it works! Best of luck to you.
12 Apr 18, Dale Westergard (New Zealand - cool/mountain climate)
I live in Utah, USA. We grow most vegetables here, and potatoes do well. Where could we obtain some starts (slips), etc. to start growing kumara? I've been to NZ several times, enjoying everything about Aotearoa, especially, Kumara. Would appreciate any helps/suggestions. thank you. Dale Westergard.
Showing 1 - 10 of 34 comments

Hi there :-) found this thread while looking for a diagram of kumara (sweet potato) and thought this info might help you Jason. In early Feb, had this awesome fella come show us how to plant kumara in the traditional way, used successfully by Maori before European colonisation. I recently emailed him asking for general care and cultivation tips... this was his reply: "Kia ora ano sis, chur mean, glad to hear the kumara are in abundance! Have y'all pulled the runners up yet? - about 3 weeks ago you shouldve pulled up the runners on a sunny day and exposed the roots to the sun for a few hours to kill them. Otherwise the plants direct energy away from the tubers and into setting down new roots via the runners and your kumara wont be as big as they could. If you havent done it yet, still do! At that point you can also start harvesting the new shoots of vine growth - pick leaves and vines that are still that brighter green and use it like puha or watercress. If you eat mature leaves it might upset your stomach so kia tupato! (you probably already know all this!). This has same effect of directing energy to the tubers." For your reference, "puha and watercress" are greens that can be added to salads or boiled/blanched similar to spinach and silverbeet and "kia tupato" means I need to "be careful" - eating mature leaves can be harmful! Well, I am off to pull up the runners and expose them to the sun! Glad there is some today :-) Good luck with the kumara growing!! "As the garden grows so does the gardener." - Proverb

- Starrlite

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This planting guide is a general reference intended for home gardeners. We recommend that you take into account your local conditions in making planting decisions. Gardenate is not a farming or commercial advisory service. For specific advice, please contact your local plant suppliers, gardening groups, or agricultural department. The information on this site is presented in good faith, but we take no responsibility as to the accuracy of the information provided.
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