Sweetcorn

It’s well known that corn on the cob quickly loses its sweetness after harvesting, so it’s particularly beneficial to be able to pick a few cobs and start preparing them for a meal with the minimum time gap!  And certainly not the time gap of harvest, packaging, sent to distribution centre, sent to supermarket, collected, stored in fridge for a few days…

It’s less well known that you can leave the corn to mature on the cob.  There are plenty of recipes for using dried corn too!  This versatility is one of the reasons, corn is a staple food in many countries.

The disadvantage for sweetcorn as a home-grown crop is that it requires a fair amount of space to grow.  You need a minimum of 6-12 plants set out as a square with a gap of 30-45cm between plants to get effective pollination.  For 6 plants, that’s approximately 2m by 2m.  However, you can follow the “3 sisters” approach of growing beans and pumpkins in the same patch which makes a huge improvement in productivity for the space!  The pumpkins create ground cover which significantly reduces weeds in the patch, while the beans use the sweetcorn as a climbing frame!  I’ve tried this approach, but the biggest space I have available is right on the “wild” edge of my garden and my bean plants get devoured before they’re big enough to think of flowering.  However, the pumpkins have done sterling work as ground cover!

I planted “rising sun” in 2021 as it’s bred for shorter growing seasons and I wasn’t sure how long sweetcorn would generally take to ripen.  From sowing in early May, the seedlings were peeping through in 10 days!

They were ready to plant out in early June along with a couple of pumpkins.  As it turned out, there were a few rogue potatoes in there too, but they didn’t seem to cause any problems – I was just careful when I harvested them to avoid damaging the roots of the corn and pumpkins.

The plants developed well in July 2021.

To decide when to harvest, you need to check the tassles hanging out of the cob – if they still look fresh and green, wait a while.

By late August, the crop was growing well.  However, a late decision to add a cage over the bed to protect the brassicas from caterpillars meant that the pumpkins couldn’t be insect pollinated, although it did enjoy using the net as a climbing frame!  There are several recipes for eating pumpkin flowers and buds, but I hadn’t the heart to harvest them as they’re such beautiful flowers!

Although I harvested one cob in late August, the majority were ready in September.

Patience was rewarded with a lovely cob with very few unpollinated niblets!

I enjoyed the home grown corn so much that I tried again in 2023 with “Sweet nugget”. I was drawn to this variety as it boasted a capability to cope with “less than perfect summers” which was a fairly kind description of summer 2023! I was short on space, so I squeezed the plants into a round bed which was much smaller than I should have used for 6 plants. I was lucky and got some decent cobs.

After such a poor summer and with no hope for a sunny autumn, I cleared the bed out early to get onion sets planted for 2024.  So I ended up with a handful of immature corn – you see these quite often in salad mixes!

Yield Summary Table

Crop	Year	Soil area (m2)	Soil depth (m)	Annual harvest (kg)	Mass yield (kg/m2.d)	£ yield (kg/m2.d)	Calorie space* (m2)	Protein space* (m2)
Rising Sun	2021	2	0.3	4.871	0.01778	0.04	937	221
Sweet nugget	2023	1.227	0.3	1.459	0.01025	0.02	1919	453