SOW it NOW
You can sow sweetcorn this month wherever you live in Australia. The seed germinates readily in prepared soil, but if you don’t have a bed vacant right now, or if you are expecting a week of rain (this could rot the seed), start them in multi-cell punnets. Don’t use single-cell punnets, as corn hates root disturbance and the seedlings would be seriously set back when you separate them.
Fill the punnets with a commercial seed-raising mix or homemade compost, firm it in, then level it off. Make a planting hole in the centre of each cell with your finger, 2–3cm deep, drop in a seed, cover it with mix then water well. Soaking seed overnight first speeds up germination.
Corn thrives on rich soil so throw everything you’ve got at it – plenty of well-rotted compost or manure and a good handful of blood and bone, with a fistful of potash per square metre. Fork into the soil then rake it level. If you are direct-sowing, drag the edge of your rake through the soil to make furrows 5–7cm deep, 75cm apart. Make at least three rows to form a block. This will ensure good distribution of pollen, which means plenty of kernels on your cobs. Drop in two seeds every 15–20cm along the row (thin out the weakest one after germination), cover with soil then water well. To avoid the seed rotting in the ground or punnets, let the soil dry out before re-wetting.