Urban Food Garden

Growing Corn

  • Large plant that needs plenty of space if it is to grow decent sized ears.

  • Requires a rich well drained soil with a slightly acid to neutral ph.

  • Needs protection from the wind as can be easily blown over.

  • Likes plenty of sun, so needs to be grown in full sunlight. Corn also needs
    warm soil (15+ Deg. °C) for seeds to germinate and seedlings to grow rapidly.

  • Is susceptible to frosts at any stage of its growth.

  • Is wind pollinated. Meaning that the pollen is blown from the male flower (the tassel) to the female flower (the ear with its sticky silks). 

Apply fertilisers as per the STANDARD VEGETABLES rate then turn the bed over and rake flat.

PLANTING SCHEDULE (South Eastern Australia)
  • TRADITIONAL SPACING: 30cm apart in each row and 75cm between rows.

  • RAISED BED COMPACT SPACING: 35cm apart in a triangulated pattern.
    For more details see: PLANTING CORN IN A RAISED BED

Corn is wind pollinated, in order to maximise pollination it is best to plant it in a block rather than a single row.  That way the pollen is more likely to be blown onto neighbouring corn plants. This is especially so if a single row of corn is planted at right angles to the prevailing wind. You will know if your corn cobs have not pollinated properly as some or all of the corn kernels do not swell up

Corn needs to be grown in a block of at least eight plants to maximise pollination rates.

Plant into bare soil as it is warmer than soil covered in mulch. Corn needs a soil temperature of 15+ Deg.°C for seeds to germinate and seedlings to grow rapidly.


Plant 3 seeds 2 cm deep in a tight grouping in each place you intend to grow a corn plant then thin out to the strongest seedling when the seedlings are about 4 or 5 cm high.  Lay any surplus removed seedlings next to the remaining ones as they will act as decoy food for slugs and snails.
If all the seeds fail in a single group then carefully transplant a  spare  seedling from a neighbouring group.  Do not replant failed groups with more seeds. This is because all the corn needs to mature at the same time if they are to be properly pollinated


Corn seedlings do not like having their roots disturbed.  If you are planting seedlings they will transplant more easily if they have been grown in single cell seedling trays as this minimises root disturbance.
Water both the roots and leaves of the seedlings with liquid fertiliser when transplanted. This is because leaves can also absorb nutrients.  Watering seedlings with liquid fertiliser increases the survival rate and helps them to establish more quickly.

Corn seedlings grown in single cell seedling trays with transplant more easily.


Corn needs a good drink, especially when the cobs are forming.  Give them a heavy water every second or third day in dry weather.
Place mulch around the base of the corn once the weather warms up to minimise water lose due to evaporation.

    Often scratch out seeds and seedlings in their quest for worms.  For information on how to protect your young corn from birds see DETER – BIRDS
    Can do significant damage to seedlings but once the corn has grown the damage is minimal.  For information on how to protect your young corn from slugs and snails see DEFEND – SLUGS AND SNAILS
    Sometimes maturing corn cobs are attacked by the Corn Earworm caterpillar.    These caterpillars tend to only damage the tops of cobs.  The caterpillars can be removed by hand or killed with Derris dust.  If your corn cobs have been attacked by Corn Earworm caterpillars then just cut off the damaged part.  The rest of the cob is still quite edible.

Corn usually takes between ten and twelve weeks to mature.  The cobs are generally ready to be picked when the tassels turn a brownish colour, though sometimes hot winds can turn the tassels brown prematurely.
If you are not sure then carefully peel back the top husks surrounding the cob and inspect the kernels to see if they are ripe.  If not quite ready then put back the husks and check again in a day or two.

The main problem with harvesting corn is that the cobs mature at the same time.  The period between when the first cobs ripen and when they become overripe and begin to harden is only about a week to ten days.  So to avoid wastage you will have to process your surplus.  For more information see PROCESSING CORN COBS

Corn cobs are generally ready to be picked when the tassels turn a brownish colour (left). You can inspect the corn to see if it is ripe by peeling back the top husks (right).