How To Sow & Grow Sweetcorn, Babycorn & Popcorn

The principles for growing Sweetcorn, Babycorn and Popping Corn varieties are basically the same, the main differences coming at the time of harvest.

A warm growing season is the most critical success factor with all varieties; whilst we now offer several varieties that will perform well in lower temperatures, the fact remains that the warmer the growing conditions the better your crop will be. If you have the room, we thoroughly recommend growing all or some of your crop under protection, especially if you're growing sweetcorn in the north.

Here at Victoriana we grow both an outdoor crop and a protected crop each year; this not only guarantees a crop if we have a cold summer but also provides an extended cropping in normal years, when we harvest from both outside and inside.

Whilst our outdoor crops are grown in the ground, we grow our protected crop in containers, planting two plants per 12 litre container.

For Growing Outside

• Sow under protection in small pots or modules late April to early May.
• Germinate at a temperature of 68-80ºF (20-26ºC).
• Set out plants after all risk of frost has passed and when air temperatures are improving - approximately late May onwards.
• If temperatures are still low, continue to grow on under protection, but pot plants on to prevent them becoming root-bound.
• Set out 15" (37.5 cm) apart in rows 18" (45 cm) apart. For Babycorn varieties you can plant a little closer – 6" (15 cm) apart in rows 12" (30 cm) apart.
• For good pollination sweetcorn needs to be planted in blocks rather than a single row or two. The exception to this is Babycorn varieties as they do not need to be pollinated.

For Growing Under Protection

(This will give you early sweetcorn without the worry about cold temperatures.)

• Sow under protection in small pots or modules from March to early May.
• Germinate at a temperature of 68-80ºF (20-26ºC).
• Set out into the border soil of your polytunnel or greenhouse when plants are around 6" (15 cm) in height.
• Set out 15" (37.5 cm) apart in rows 18" (45 cm) apart. For Babycorn varieties you can plant a little closer - 6" (15 cm) apart in rows 12" (30 cm) apart.
• Alternatively, grow in tubs or containers.
• As sweetcorn is naturally wind-pollinated you will need to artificially pollinate. At the first signs of the flowers at the top of the plant releasing pollen (evident by yellow 'dust' clouds when you brush past the plants or yellow 'dust' on the lower leaves and surrounding the plants) gently give the stem of each plant a shake to release pollen and encourage it to drop from the top flowers to the lower juvenile cobs; you will need to do this daily for approximately two weeks or until no more pollen is released. The exception to this is Babycorn varieties as they do not need to be pollinated.

Harvesting

• Harvest when ready!
• For conventional varieties the cobs are normally ready to harvest when the tassels on the husk of the cobs dry and change colour to dark brown; gently pull back the husk and pierce a kernel with your fingernail, if a milky liquid is exuded the cob is ready to eat.
• For Babycorn varieties harvest the cobs when around 4-6" (10-15 cm) long and when the tassels are still green/red in colour.
• For Popcorn varieties, when the tassels on the husk of the cobs have darkened it is time to harvest and dry your cobs. Whilst it is possible to allow the cobs to naturally dry on the plants before harvesting this requires an autumn relatively free from rain; the second disadvantage of drying on the plant is that if mice find the drying cobs they will decimate them - we have experienced this to our cost here on the nursery! So cut the cobs with a little extra stalk and gently remove the outer husk and tassel debris.

Top Tips

• Protect newly sown seeds from mice. Mice are notorious for sniffing out seeds!
• Repeat sowings can be made every two weeks from your first sowing until the end of June, giving you a succession of plants to set out, and thus an extension to the cropping season.
• Cover the soil where you are going to grow your crop with black polythene or similar a few weeks before planting out as this will absorb heat and warm up the soil.
• You can of course also plant through a polythene mulch or similar as this will continue to retain heat along with moisture - and suppress weeds.
• Protect the young plants with cloches, windbreaks or similar if the weather is cold.

Cooking Tips

Home-grown sweetcorn is much sweeter than shop-bought sweetcorn. This is because the sugar in the cobs starts to turn to starch the moment the cobs are cut. To get the best from your cobs cut them as close as possible to when you are going to cook them. It is not unknown for Americans (famous for their love of corn) to take a saucepan of boiling water with them to plunge the cobs into the moment they cut their corn; if you do this, please be careful!

Plunging the freshly-cut cobs, husk and all, into a bucket of water and then barbecuing them is also a way to maintain that super-sweet flavour – no need to wrap in foil as the wet husk will protect the kernels and as the outer layers char they will give a fantastic smoky flavour.

For something completely different, and to maximise crop space, try growing sweetcorn using the Three Sisters method.