Return to Listings Page



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.

Meet the Author: Jo Blackwell
Jo Blackwell

Jo Blackwell is our well-established Horticultural Advisor and the Kitchen Gardener in Stephanie's Victorian style Kitchen Garden. She caught the gardening bug when she bought her first home 21 years ago. Her first greenhouse soon followed and she later gained an allotment.

As well as tending the Harrod Horticultural Gardens, she enjoys maintaining her own vegetable plot at home. She has been a gardener for Harrod Horticultural for over 4 years now and has a wealth of experience in organic vegetable growing, ornamental gardening and in using all Harrod products.


Further Information

Mulch with organic matter (compost or leaf mould) to conserve moisture and suppress weeds. Mound soil over the roots, which appear at the base of the stems. Take care of these roots and hoe /weed carefully as they are shallow rooted.  We use Strulch garden mulch at the Harrod Kitchen Garden which is great for holding moisture in and keeping those roots warm.


Sweetcorn depend on their strong roots so we plant our seeds in Rootrainers to allow more room for the roots to grow and to give them the best start. Sow 1 or 2 seeds per pot, 1cm (0.5”) deep and thin to leave the strongest seedling. Water well and leave somewhere warm to germinate.  When they have reached 15cm (6”) high they can be hardened off ready for planting out.  Plant out indoor-raised plants at the end of May or early June depending on the weather.  A good tip is grow courgettes in amongst your Sweetcorn as this encourages pollination of both vegetables and makes more use of the space.

Sweetcorn grow adventitious roots to help support the weight of the tall plant however if your plants start to sway or look like they will become uprooted apply some soil or well rotted compost at the base of the plant (mulching).  You may have to stake plants individually if they are tall or the location is exposed.

Water well in dry weather; this is vital when the plants are flowering.  Tap the tops of the plants when the male flowers (tassels) open to help pollination; poor pollination results in sparsely filled cobs. Liquid feed when the cobs begin to swell.

Remember to keep weeds under control as your plants will need all the nourishment from the soil they can get.


Mice - These pesky rodents will eat the newly planted seeds.  If this becomes a problem place traps around the area where your seeds are sown.

Birds - Pigeons can damage ripening crops - Either net the entire crop or place plastic bags over individual cobs.

Slugs and snails: These feed on the young seedlings and you''ll see the tell tale slime trail on the soil around your crop, as well as on the leaves.  There are many ways to control slugs and snails, including beer traps (Slug Inns), natural pellets, sawdust or eggshell barriers and copper rings and tape.


Sweetcorn doesn’t store well as mentioned before the sugars turn to starch as soon as they are picked.  It can be kept in the fridge for a day or so but is best eaten as soon after harvesting as possible.


Freshly boiled with butter and milled pepper – can’t beat it.

Cooked on the BBQ - Use the freshest sweet corn you can get your hands on and don''t remove any of the outer leaves. Put the sweet corn in a bucket of water for 30 minutes.  Put the Sweetcorn on the barbecue and cook for 25 minutes. Turn it a couple of times.  Don’t worry about the outer leaves turning black, the sweetcorn will not be affected.  Peel off the outer leaves and you will discover the most tasty sweetcorn you have ever tasted.



You need to be logged in to post a comment on this post. .

Back To Top