How to Grow and Harvest Sweetcorn

When you picture growing corn, you may envision great runs of corn stalks in fields. But, it is not too difficult to grow sweetcorn in your own garden and you certainly don’t need acres of space. 

The result should be a deliciously sweet harvest of corn in late summer to early autumn. 


Sweetcorn Seed Varieties

Some recommended varieties of sweetcorn to try are:

Sweetcorn F1 Moonshine

An extremely sweet and juicy variety of sweetcorn, highly rated for its flavour. Harvests from August to October. 

Sweetcorn F1 Goldcrest

A midseason variety of sweetcorn that is ideal for the UK climate, producing a complete husk that protects the cob within. A vigorous grower. 

Sweetcorn F1 Sundance

An early maturing and high yielding sweetcorn variety, producing a plentiful supply of well-filled cobs from August to early September. 

Sweetcorn Summer Glow

A deliciously sweet variety that produces attractive yellow and white corns on a single cob. It should cope well even in more difficult, cooler locations.  

Sweetcorn Swift

An early sweetcorn variety. Fast-growing, it is a reliable producer of crops and performs well even in cooler temperatures. 

Sweetcorn Conqueror F1

A super-sweet variety that produces an excellent yield of large crops. The strong-growing plants should perform well even when the British summer doesn't.


Sowing Sweetcorn Seed Indoors

If you want to get a head start with your sweetcorn sowing, you can sow seeds indoors from April. Sow seeds individually into pots.

Once all risk of frost has passed and your plants are 15cm or more in height, plant outdoors. Your sweetcorn will benefit from being gradually hardened off as you bring them outside – i.e. bring them outdoors for increasing amounts of time over a 7 – 10 day period before planting in the ground.


Planting Sweetcorn Outdoors

If you prefer to plant sweetcorn seeds directly outdoors, wait until there is no longer any risk of frost – May is usually the best month.

When planting sweetcorn in your garden vegetable patch or allotment, it is most effective to sow plants in a block. This is because sweetcorn is pollinated by wind / air movement blowing the pollen from the flowers on to the tassels below. It needs pollen from one plant to blow on to the tassels of another (cross-pollination). By planting in a block (opposed to a single row) you are much more likely for them to be successfully pollinated an ripen properly. 

Plant the seeds two to a hole in your block formation. Leave a space of approximately 40cm between each plant. The reason for this is to give the best possible chance of success. 

When the plants have germinated, leave the strongest one growing and remove the weaker one. Adding a layer of mulch around the base of the plant will help keep it retain moisture during the summer months.

If you are planting out your sweetcorn that you started indoors, the same principle applies. Leave a gap of approximately 40cm between each plant – unlike sowing from seed, you will only want to place one plant per hole of course!


Caring for Your Sweetcorn

Water your sweetcorn plants regularly, particularly during dry spells. 


When to Harvest Sweetcorn

The harvest time for your sweetcorn will depend on the variety, but the majority of sweetcorn varieties in the UK are harvested in August and September.

The tell-tale sign that your sweetcorn is ready for harvesting is when the tassels coming out of the end of the cobs go dark brown. This shows that they have picked up pollen and fertilised, which is needed in order to produce and ripen the individual corns. Test by peeling back the sheaf and gently squeezing one of the kernels. If the liquid that comes out is a milky colour, the sweetcorn is ripe and ready. If it’s clear, leave it longer. If there is no liquid at all, you may, unfortunately, be too late harvesting.


Find a wide range of sweetcorn seed varieties at Hillier Garden Centres