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Sweet Corn & Maize (Zea mays)

GROWING SUMMARY​

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  • Onions are frost hardy and germinate best between

  • Timing:  

  • Direct Seeding

  • Growing Seedlings
    Germination temperature

  • Bed Preparation
    Raised beds
    On the flat

  • Plant Spacing
    Germination temperature

  • Irrigation
    Germination temperature

  • Pests and Diseases
    Germination temperature

  • Harvesting
    November – January depending on variety & location

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GROWING SUMMARY​

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  • Corn is a tall, thick, frost tender, annual grass.

  • Plant directly into the ground in spring and early summer. The soil temperature must be at least 18°C. 2 seeds 20mm deep, every 300mm with rows at least 1metre apart. Thin to the strongest plant after they germinate. 

  • Corn does best in fertile soil. Pale leaf colour indicates low nitrogen. A side dressing of a high nitrogen fertiliser (fish emulsion or blood and bone) will help.

  • To ensure good pollination plant in blocks 4 or more rows wide rather than in long single rows.

  • 6 weeks after planting the corn under sow the young plants with soya beans. The will provide a living mulch that suppresses weeds and at the end of the season you can flail mow or slash the corn stalks with the soya bean plants and turn the whole lot back into the ground as a perfect green manure. 

  • Corn ear worm is a caterpillar that enters the cobs from the top and eats its way down through the kernals, It can be controlled by spraying with Bacillus thuringiensis (BT, Dipel) once the silks have formed. Alternatively carefully dust the tassels on top of the young cobs with derris dust.

  • Drip irrigation. The crucial time for consistent watering is when the male flowers at the top of the plant are dropping pollen on the silks at the top of the young cobs. Lack of water at this time will prevent pollination and result in badly formed cobs.

  • Harvest when the cobs/ears are fat and well formed and the silks brown and dry - peel back the outer husks to check before harvesting..

  • Extend the harvest by planting up to 3 successions at one month intervals. 

VARIETIES​

  • Traditional varieties of sweet corn.
    These need to be picked and eaten immediately for maximum taste and sweetness. 

  • Super sweet hybrids.
    Modern varieties which have been bred to slow down the sugar to starch conversion after picking. These cultivars are so sweet you can eat them raw in the field, however, you need to grow them in isolation beause if they are pollinated from a different variety grown near by they and their neighbours will end up tough and starchy.

  • Popping Corn.
    Popping corn comes is a range of crazy beautiful colours from gold/yellow through to dark blue. The cobs need to be left on the plants and harvested when dry and hard, late in the season

  • Maize.
    Maize is the cereal form of corn. It is allowed to fully ripen on the plants until dry and a bit shriveled (dented). It can be stored, shucked and ground into flour or the coarser corn meal and polenta. It comes in both white and golden varieties. 

MORE INFORMATION

Pollination

Corn was domesticated by the indigenous peoples in Mexico about 9,000 years ago and is totally dependant on humans for propagation. Dried out, fully mature corn cobs can drop on the ground but the seeds themselves will not separate from the cob and fall off and grow. 

Corn is monoecious, there are separate male and female flowers on the same plant. Wind and to some extent insects move the pollen from the male flowers on the top of the plant to the female silks or tassels on the female flowers. Each thread of silk is attached to a single kernel so it is important that the tassels receive plenty of pollen from the male flowers ensuring a full kerneled cob at harvest.

Wind pollination also means that your corn patch can be pollinated from a nearby plot of corn. If you are planning to save seed from corn then you need to grow a single variety more than 100 metres from any other corn plants. The same is true for super sweet hybrids.  You can also plant several varieties on the same day as long as they are separated by 7-8metres and mature at least 12 days apart. Staggering plantings by more than 12 days will also work. The aim is to make sure one block of corn cannot pollinate another block.

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Succession Planting

A bock of sweet corn all planted on the same day can be harvested for 3-5 weeks. If you want to extend your season you need to plant once a month from spring to mid summer. 

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