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 17°C and 35°C. (Show °F/in)
  • Space plants: 40 - 60 cm apart
  • Harvest in 15-17 weeks.
  • Compatible with (can grow beside): Best in Separate bed

Your comments and tips

18 Nov 20, Aitaua (New Zealand - sub-tropical climate)
Hi.. Can these sweet potatoes useful for planting here in Samoa?
19 Nov 20, (New Zealand - temperate climate)
They should be.
17 Nov 20, Henk Stengs (New Zealand - temperate climate)
I have experimented with kumara for several years in Greymouth with mixed success so last summer tried growing them in old car tyres. Their black colour absorbs heat thereby increasing soil temperature. Three sets of tyres were used, each stacked two high. These were placed inside our tunnel house on the surface in a sunny position and filled with soil, with one slip allowed to grow from each central position from late November. Harvesting took place in early April, producing a total yield of 9 kg, with about 60% of shop quality, my best result yet. When I harvested the tubers I saw that they were confined to centres of potential growth areas, with no root development at their circumferences inside the tyre rims. Therefore over half of the volume of soil in each pair of tyres was not utilised. This year I will plant 2 sllps per tyre pair, positioned diametrically opposite, with root ends inside the rims to see if this will give a better result. I am interested in hearing from anyone else who has tried growing kumara in tyres. .
18 Nov 20, (New Zealand - temperate climate)
They grow sweet potato/kumara where I live (Qld Australia) by the thousands of acres. They hill the soil up into rows about .5m high with a base probably .7m wide. They take pieces of vine (called a slip) about .4m long, strip most of the leaves off. Keep the growing tip on it. They place the whole slip just under the soil horizontally with the growing tip sticking out of the soil. Where each set of leaves were on the slip, roots will grow and potatoes will form. Water each day for the first 2-3 weeks. Just a side issue, tires may not be the best thing to grow vegetables in. Rubber compound/chemicals could leach into the soil.
20 Feb 21, Jay (New Zealand - cool/mountain climate)
Hi could you provide time of year for this method thanks
10 Aug 20, Nicky Holmes (New Zealand - temperate climate)
Hi can you please tell me if Dunedin is the right temperature to grow Kumars outdoors or is it to cold? Thanks.
11 Aug 20, Anon (New Zealand - temperate climate)
Go to Sweet potatoes/ Kumara page, temperate climate zone and check the planting calendar.
27 Jun 19, Ana (New Zealand - temperate climate)
Try this page: https://www.koanga.org.nz/grow-great-kumara/. They have the most thorough advice on growing kumara that I've seen.
06 Apr 19, Sam (New Zealand - temperate climate)
Hi there.. I harvested my Kumara in March and unfortunately most of them tubers had multiple small holes in them. Looks like some type of insects got there first and ruined it. Is there anything that I can spray them with and kill them little bugs before they ruin my crops next season.. cheers
12 Jul 20, Brendan (New Zealand - temperate climate)
I've had good success planting an overwintering crop of mustard seeds immediately following kumara harvest.
Showing 11 - 20 of 58 comments

It may survive if you plant it now - might not grow much or produce a crop. Might be better to try again say Oct and plant out Nov Dec. You are temperate climate.

- Mike Logan

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