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 New Zealand - cool/mountain 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

Your comments and tips

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02 Oct 18, Warren Leedes (New Zealand - cool/mountain climate)
Firstly thanks for the web site I would like to grow the different coloured Kumara, how do I go about getting seeds please? Any advice would be gratefully received Kind regards Warren Leedes
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04 Oct 18, Paul (New Zealand - sub-tropical climate)
Plant the tubers that you want to grow but in a separate bed. They will sprout lots of shoots which will also have roots near the base. When the shoots are 40 to 50 cm long put a fork under the tuber and gently lift it out. Separate the shoots and plant them in the bed you have prepared for them as indicated in the article above. Last year, before I knew this, I planted several tubers where I wanted them to grow but after learning the right method I dug up three and planted out about 50 slips. The slips can be left in water while you are waiting to plant them out and in a few days mine put out prolific roots where the base was under water. You can also start the sprouting inside, cutting the tops off tubers and putting the cut down in shallow water, then planting them out when they start to sprout. Roots will also start growing but later than the shoots. Look for the eyes in the tubers as they are where the shoots come from.
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08 Oct 18, Mike (New Zealand - sub-tropical climate)
Also you can use 50-60cm sections of the growing plants 6-8 week old and plant them along the ground with the tip out of the soil. Roots will grow from where each leaf joins the vine.
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19 Sep 18, Eddy (New Zealand - temperate climate)
Can they grow on canterbury christchurch
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06 Oct 18, denise (New Zealand - temperate climate)
i live in Kaiapoi and grow in tubs. the soil is warmer
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21 Sep 18, Mike (New Zealand - temperate climate)
Did you read the notes here. I suggest you do and pay attention to when to plant.
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16 Aug 18, Adrienne (New Zealand - sub-tropical climate)
Can you please tell me what is the best type of fertiliser to prepare the soil for kumara?
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11 Sep 18, Mike (New Zealand - temperate climate)
Any general fertiliser - but probably something with a fair bit of P in it. N P K - something like 10 -14N, 6-10 P, 10-15 K.
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25 Mar 18, Julie Casidy (New Zealand - temperate climate)
When should I dig up Kumara? I didn't get them into the ground until late in spring. Should I do so before the first frost? I live in Wellington and never grown them. Yours thankfully Julie
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30 Mar 18, Prakash Chandra (New Zealand - sub-tropical climate)
You can dig out Kumasi when you see the end of vines and the leaves are turning yellow or just take a hand fork and dig around one plant carefully and see but do not dig the plant outright
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Showing 31 - 40 of 61 comments
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It's best to use dried out cow manure, which has been broken up into a almost powdered state and dug into the soil below where you are going to put the sprouts, before planting. You can do this by putting the cow pads into a cement mixer with a few old 1/2 bricks and tumbled for 1/2 hr or so, or just using a shovel on a hard surface. Concrete path etc. Just bust them and pulverise as best you can. Don't use fresh manure under any circumstance. Horse manure is pretty useless and has too much acid, while chook manure is best just laid on top of soil around the plants after a good showing of leaf from the runners. Best to use something like Organic Life or Dynamic Lifter, chook manure that has been treated. So every time you water, the nutrients will just seep into the soil at an even rate. A small sprinkling of garden lime dug in with the cow manure is a good idea too. If you ever come across the original white sweet potato, plant them too. Much better texture and taste, than the purple. Anyway....best of luck !

- Gerard Plant

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