My Favourite Crop: Sweetcorn - Growing
Dandelion / Growing

My Favourite Crop: Sweetcorn

Years ago, my dad went on a mission to find *proper* fresh sweetcorn; he waxed poetic about the incredible flavour difference between fresh and store bought. Did you know that the sugars in sweetcorn start breaking down into starch almost immediately?  When I learned that I decided the only way I could give him the sweetcorn he was looking for, was to grow my own.

It’s a bit of a fiddly crop, but not prohibitively so. The first job the UK gardener has is to choose a quick maturing variety to ensure your crop is ready to harvest before the season turns cold. I usually choose “Swift” and/or “Early Xtra Sweet” and sow my seeds indoors in the spring. Sweetcorn has a reputation of not wanting its roots disturbed so I find toilet paper tubes are ideal for this. Cut one end into four sections, fold them up and fill with seed starting compost while you are growing indoors; when you go to plant out just fold the ends back down to allow the roots easy access to their new home.

The long days of summer mean happy sweetcorn will genuinely surprise you at how quickly it can grow.  Usually around July/August you will see immature cobs form on the strong stalk and sticky hairs come out the top of the cob which are called silks.

These silks are each attached to a single kernel of corn and must all touch pollen in order for the kernel to swell. Unlike most other plants, sweetcorn is wind pollinated (Fun fact: Baby corn is just unpollinated sweetcorn). This is no problem if you are growing a whole field of it but backyard crops need some additional help to ensure you are able to harvest a cob full of pollinated kernels.

The pollen source comes from the top of the plant and I often find one plant is rarely in synch with itself in terms of producing silks and pollen at the same time. Here is the fiddly bit: if growing under cover you will need to collect the available pollen (any dry surface works but I find a paper plate ideal) and dip the silks into it. Any of your sweetcorn plants can pollinate the others. Aim to do this two or three times to ensure all silks have been pollinated. Those which have been will start to turn brown in around a week.

The next bit involves waiting! When the silks are all brown and it has been at least two (in my experience more like four) weeks since pollination, with the sweetcorn still on the plant you can carefully peel back the outer leaves on the cob to expose just the top kernels. Pierce one and if the liquid is milky, it’s ready to harvest. If it’s clear, it’s not yet ready.

Now the best part: the eating!  Aim to pick only when you plan to eat – no more than 30 minutes from plant to table is ideal. You will find super fresh sweetcorn cooks faster than you are used to so emerge in boiled (but not boiling) water for 30-60 seconds and enjoy.

Common sweetcorn pests and how to deal with them:

Earwigs – they will eat the silks so the kernels can’t pollinate.  Fill a lidded plastic pot (an old dip container works great) with oil and soy sauce and punch holes in the top of the container large enough for earwigs to access. Bury the container up to the lid to allow them access.

Wireworms – If you notice your previously healthy plants starting to shrivel for no obvious reasons, dig one up carefully and check the base of the plant around the roots. Wireworms are orange-ish and will eat holes in the stalk, killing the plant from the ground up. I lost *many* sweetcorn plants to wireworms this year and found that half a potato per square metre makes for an excellent trap and preferred meal for them. Lift the potato every few days to nab the beasties and try to keep the population down for the following year.


By Emily Hairstans