This is a guide on how to grow corn, its sun requirements, when to plant it and harvest. It also covers the different pests that may affect your crop and what you can do about them.

Soil

What soil is good for Corn?

Well draining soil enriched with well rotted organic matter.

Position

How much sun does Corn need?

Full sun, protected from strong winds.

Frost Tolerant

Is Corn frost tolerant?

No

Spacing

How much space does Corn need?

Roughly 30cm apart. Since corn cobs are pollinated by wind, it's important to plant them close together. Plant corn in blocks of at least 3 or 4 rows, rather than a long single row. Planting in blocks allows for a more even dispersal of pollen, producing cobs with even and consistent kernel production. 

Planting

When should I plant Corn?

Corn is a warm season crop. Standard corn varieties should sown once soil temperatures have warmed above 12°C. Sweetcorn varieties should be sown once soil temperatures have warmed above 18°C.

Usually planted out in spring, depending on your climate. Wait until the danger of frost has passed. 

If transplanting seedlings, plant out in the early morning or evening and/or on an overcast day. Avoid planting at peak sun times or on windy days, this will allow your plants to settle in comfortably and protect them from windburn and sunburn.  

Feeding

What do I feed Corn?

Apply an organic fertiliser throughout the season.

Harvesting

When can I harvest Corn?

Cobs are generally ready for harvest around 3 weeks after flowering, when the silks at the top of the cobs have turned brown. To be sure, peel back some of the husk and pierce a kernel with your finger nail. It should release a milky liquid. If the liquid runs clear, it needs more time to mature. If no liquid comes out, it means the corn is over-ripe (as the sugars have converted to starch). 

To harvest, grasp the ear firmly, then twist and pull downwards. 

Pests

What pests does Corn get?

Slugs, Aphids, Corn Earworm, Cutworm, Armyworm, Flea Beetle, Thrips, Root Knot Nematode, Mites, Slug, Snail, Leafhopper 

Diseases

What diseases does Corn get?

Anthracnose, Fungal Leaf Spot, Bacterial Leaf Spot, Charcoal Rot, Rust, Smut, Downy Mildew, Stalk and Ear Rot, Leaf Blight, Bacterial Leaf Streak Disease, Steward’s Wilt, Mosaic Virus, Corn Lethal Necrosis

Troubleshooting

How do I troubleshoot my growing problems?

Shelter corn on days where strong winds are predicted.