Sweetcorn

Ease of Growing: (Scale 1-5) - 3

It can be tricky to grow as it is very dependent on good weather conditions but given a hot summer it will shine.  Sweetcorn loves sunshine and our erratic weather conditions can affect the success of the crop.  Plants may grow but may not set their cobs or they have partially developed cobs if we have a bad summer.

How time consuming

Once they have got going they are very easy and apart from watering no aftercare is really needed. Watering is required when the plants are establishing and when kernels are swelling – it should not be necessary to water much in between apart from during really dry hot spells.

Recommended varieties

Sweetcorn is most successful in long hot summers, though many modern cultivars are better suited to cooler climates.  Choose one of the new varieties that have been introduced which withstand our unpredictable summers.

‘Lark’ AGM - Early maturing and high yielding with sweet & tender, top quality cobs.

‘Luscious’ F1 – This Organic maincrop variety has good flavour and texture, this bi-colour, maincrop variety has good vigour and is relatively tall.  Producing medium to large sized cobs with yellow and white coloured grains.

‘Earlybird' AGM - 2nd early. Supersweet variety with vigorous plants and good sized, uniform cobs. Modern cultivar bred for difficult summers.

‘Golden Giant’ AGM - Supersweet variety with a vigorous main crop with large, good quality cobs.

Sweetcorn ‘Swift’ F1 - Extra tender sweet. This variety is one of the best to choose for growing your own sweetcorn in the UK.  

Home grown vs. Supermarket

There is just no comparison with a freshly harvested sweetcorn cob from your garden and one bought from a supermarket.   As soon as sweetcorn is picked the sugars start turning into starch and the cornels can become tough and dry when stored. So the fresher the better!

Best Sites & Soils

Choose a warm sheltered, sunny position, protected from strong wind, on any fertile garden soil. Add up to two bucketfuls of organic matter, such as rotted manure, and also rake in Blood, Fish & Bone fertiliser before planting.  Sweetcorn is less successful on dry or heavy soil.

When to sow

Sweetcorn does not germinate when soil or compost temperatures are below 10C (50F). So if you are sowing direct outside don’t plant too early.  Wait until mid-late May when the soil will have warmed up – depending on weather conditions of course!

If you have a greenhouse or a warm place indoors sow at 18-21C (65-70F) from mid-April to early May in modules or deep pots (or Rootrainers) at a depth of 2.5cm (1in). Use early, mid season and late varieties to extend the cropping season.

Distance between plants

Sweetcorn are wind pollinated so they should be grown in blocks rather than rows, 45cm (18in) apart.

When to harvest

At the end of the Summer/early Autumn test for ripeness when the tassels have turned chocolate brown - squeeze a cornel between thumbnail and fingernail; if a watery liquid squirts out, it is unripe; if it is creamy, the cob is ready; if paste-like it has gone over. Twist ripe cobs from the stem. They rapidly lose their flavour so have a pan of boiling water ready before you harvest, ready to plunge them in.