Growing Sweet corn, also corn,maize

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 61°F and 95°F. (Show °C/cm)
  • Space plants: 8 - 12 inches apart
  • Harvest in 11-14 weeks.
  • Compatible with (can grow beside): All beans, cucumber, melons, peas, pumpkin, squash, amaranth
  • Avoid growing close to: Celery.
  • A seedling
  • A young corn plant
  • Feathery cobs on side of stem. Male flowers at top.

Plant in 4 by 4 blocks to encourage germination Pick when the silky threads on the cobs turn brown or black. Part the top of the leaves and test for ripeness by pressing a grain with your fingernail. If it is milky, it is ready.

Early varieties ripen quickly and are sweeter when just picked.

Avoid planting coloured maize ( for drying) near sweetcorn as they will cross-pollinate and spoil the cobs on both.

Culinary hints - cooking and eating Sweet corn

Pick and cook within an hour. Remove the silks and outer leaves.
Best flavour if microwave about 4 minutes per cob.
Can be barbequed wrapped in foil
Cook large amounts in a stock pot until test soft.
Sprinkle with black pepper and dip in butter.

Your comments and tips

14 Feb 22, Julia (New Zealand - temperate climate)
Hello I planted corn glass gem and because I had a few gaps in the plot I planted about half again with sweet corn. It has been 15 weeks since planting on 25oct and they are tall but the cobs and not cobbing very much. They seem immature. Is this perhaps as I planted the two types?
04 Mar 22, guggerlugs (New Zealand - temperate climate)
When I plant sweetcorn seed I usually plant a few more than needed if you have failures they are readily transplanted then you can fill the gaps, if they all germinate if you leave a bit of space at the edges you can shift them there.Don't plant too many but plant batches about 4 weeks apart if you have the space then you won't get over run with corn my third crop is just forming tassles now as we finish the last few cobs.
22 Feb 22, Anonymous (New Zealand - sub-tropical climate)
Did you over plant the plot? Corn needs to be spaced as the directions say and it needs to be well watered and fertilised. Plants that germinate later than some can be left behind and not grow well, small thin weak.
17 Feb 22, Celeste Archer (Canada - Zone 7b Mild Temperate climate)
I'm not certain - but when I read your post the first thing that came to mind was a Boron deficiency -- corn likes boron the same way that sunflowers like boron. From the net a study of corn and boron results: It was concluded that: (1) a lack of boron can cause blank stalks and barren ears; (2), the supply of available boron must be continuous; and (3), the critical level of boron in the upper leaves appears to be in between 11 to 13 ppm. I suspect you can apply boron the same way you would to sunflowers (though I am not certain)-- from the net for sunflowers: When the plants are 30cm (12) tall, dissolve 5ml (1 tsp) of borax (for boron) in 350 ml (12 fl oz) of water and spread the solution over 5m (15′) of row. Be careful not to over-apply this solution.
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 -
Showing 1 - 10 of 17 comments

Is it too late to plant corn here in zone 7b?

- Elise Blanchard

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