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

Your comments and tips

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
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
21 Mar 18, Kathy charles (Australia - temperate climate)
I planted 3 tubers of yellow and 1 purple sweet potato in October 2017 now March have picked first purple one but cannot find even a little yellow tuber. Healthy looking plants but WHY no s/potato. Thank you in advance
23 Mar 18, Mike (Australia - sub-tropical climate)
Cut off some runners/vine and plant them - better than tubers. About 18
10 Mar 18, Greg (Australia - sub-tropical climate)
I'm in Ipswich , SE QLD. I planted five purple sweet potato slips back at the beginning of August (2017). They have been in the ground seven months. They have grown well but have not flowered or died back at all, unlike the normal orange ones i grew the previous year. I've had a little bit of a dig around but have not found any tubers at all. Has anyone grown these before in my climate and should i be expecting to find tubers by now? Perhaps they went in at the wrong time of year? If i could upload a photo here, i would. Thanks for your help!
11 Mar 18, Mike (Australia - sub-tropical climate)
I planted the orange ones one summer and they produced heaps. The next year nearly nothing. I talked to a farmer a few months ago and they plant slips. That is they go onto an existing growing crop about 6-8 weeks old and they take slips/runners/vine
13 Mar 18, Mike (Australia - sub-tropical climate)
They cut this off from my post. You need a slip about 18
04 Mar 18, Sue Ussher (New Zealand - cool/mountain climate)
I live in Fairlie South Canterbury and want to know if I could grow Kumara here and what month should I be planting them
25 Feb 18, Chloe (New Zealand - sub-tropical climate)
I have two furiously shooting kumara that have been growing in the pantry (!) Whilst I was overseas. I'm located in a very sunny spot in Auckland, is there any point in attempting to grow them now? (End Feb)
27 Feb 18, Mike (Australia - sub-tropical climate)
Give it a go.
Showing 131 - 140 of 316 comments

Harvest once about HALF of the leaves start to fall over and die off (turn yellow) -- HOWEVER I'm not sure if you planted at the being of October or the end. Given good growing conditions it should take about 120 days -- if you planted at the end October then that is about 120 days.... but it could take longer -- and since the leaves have not fallen over, then I would say, it will take more time. If you planted at the beginning of October, then you are taking a lot of days -- and it could be that the growing conditions have not been optimal for the whole time.... and I would still wait for leaves to fall over... but I would start to wonder if perhaps for some reason all the conditions that your plant needs to have met in order to set tubers have not been met (nutrition, soil type/ph, water, sun light, temperatures etc.). Same rule for potatoes, harvest once the leaves started falling over and turning yellow. That is to say: as long as the leaves are a upright and green they are still collecting light and storing energy (making tubers - and making them larger)

- Celeste Archer

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