Growing Sweet corn, also corn,maize

Zea mays, var. rugosa : Poaceae / the grass family

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

(Best months for growing Sweet corn in New Zealand - cool/mountain regions)

  • P = Sow seed

October: After risk of frost

  • Sow in garden. Sow seed at a depth approximately three times the diameter of the seed. Best planted at soil temperatures between 16°C and 35°C. (Show °F/in)
  • Space plants: 20 - 30 cm apart
  • Harvest in 11-14 weeks.
  • Compatible with (can grow beside): All beans, cucumber, melons, peas, pumpkin, squash, amaranth
  • Avoid growing close to: Celery.

Your comments and tips

04 Feb 21, Helen Tapper (New Zealand - temperate climate)
This is my 2nd season of growing corn, last season was very successful, this year - not so. I have planted them almost exactly in the same spot as last season. Was that the right thing to do or wrong. The other point is that we have had some pretty crazy summer temperatures, high 20's then low to mid teens. I fertilised the garden during the winter/early spring.
05 Feb 21, (Australia - sub-tropical climate)
Better to plant in different spot. Corn is a big user of fertiliser and water. When preparing the soil add compost/manures if possible, Soils always need some fibre replacement each year. Then mark out your rows about 50-60cm apart, Scratch a furrow in the soil and run some fertiliser in the furrow - I use Bunnings rooster booster. Have the soil wet before starting, after planting give another watering. Don't water again for 3-4 days. Too wet seeds will rot. When plants are 45cm high run some more fert down each side of the plants and hill the soil up around the stalk. Corn pollinates for 5 days and you pick it approx 21 days later. I just picked 28 cobs last week. S
28 Jun 20, Judi (New Zealand - temperate climate)
My 6-yr-old came home with an egg carton of sweetcorn seeds he'd planted at school. We put them on the windowsill and they've sprouted beautifully. But it's June, and although it's very mild now (in Waikato) we're expecting to get winter weather soon. He's very excited about these seedlings and would love to grow them to fruition - do you think I could grow them in a large pot as an indoor plant?
30 Jun 20, Anonymous (New Zealand - temperate climate)
Corn needs to be planted in rows about 6-800mm apart. Seeds need to be planted about 150mm apart. Best to grow 2 or more rows together in a block for pollination. When the tassel and silks come out it takes about 5 days for pollination. Then about 21 days for cob to be ready to pick. Read up on the net.
29 Jun 20, Anon (New Zealand - temperate climate)
Corn needs full sunlight to produce a good cob. If you fail this time try a more suitable time like spring summer to try again.
28 Jun 20, Liz (New Zealand - temperate climate)
If you can stand your pot near a sunny window, you might be able to keep the sweetcorn growing. Protect it from cold temperatures and make sure it has plenty of light -
16 Jul 19, Peter field (New Zealand - temperate climate)
We havnt had a frost up in the far north(kiataia) for zonks. I have wet ground temp of 13 deg . Can i plant corn
17 Jul 19, (New Zealand - temperate climate)
It does say plant from - Sept. Soil temp 16+. We are in July - have a think about it. Do something about trying to dry out your soil. Add decompose compost or manures to aerate the soil - have good loose soil - not heavy wet soil. Corn is a summer - autumn crop so the thing about frost is not important.
10 Nov 12, Torben Tilly (New Zealand - temperate climate)
Where can one buy Purple Corn seed in New Zealand?
21 Aug 18, Philip Lim (New Zealand - temperate climate)
I have some purple corn seed if you are looking for some. Let me know your address and i will post some to you.
Showing 11 - 20 of 23 comments

This is my 2nd season of growing corn, last season was very successful, this year - not so. I have planted them almost exactly in the same spot as last season. Was that the right thing to do or wrong. The other point is that we have had some pretty crazy summer temperatures, high 20's then low to mid teens. I fertilised the garden during the winter/early spring.

- Helen Tapper

Please provide your email address if you are hoping for a reply


All comments are reviewed before displaying on the site, so your posting will not appear immediately

Gardenate App

Put GardenGrow in your pocket. Get our app for iPhone, iPad or Android to add your own plants and record your plantings and harvests

Planting Reminders

Join 60,000+ gardeners who already use GardenGrow and subscribe to the free GardenGrow planting reminders email newsletter.


Home | Vegetables and herbs to plant | Climate zones | About GardenGrow | Contact us | Privacy Policy

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. GardenGrow 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.
We cannot help if you are overrun by giant slugs.