Growing sweetcorn has a high perceived worth amongst friends and family. Often, it is seen as requiring a special skill, and mixed in with this is admiration and envy for the ‘professional allotmenter’.
The truth is that sweetcorn is one of the easiest vegetables to grow. Sweetcorn needs no special care, has a relatively short growing season, and will thrive in the large majority of summers – it requires consistent warmth rather than plentiful sun.
- April – June
- Planting depth: 2.5 cm
- Planting spacing: 40cm between plants, 40 cm between rows
- July – October
- Eat fresh
I start my sweetcorn in seed trays in May. This is when spring has turned reliably warm and there is no further risk of frost. It is possible to start earlier if you have a warm location to put your seed trays in.
If your seed trays are outdoors, it is worth remembering to cover them in some way – I have lost one sowing due to birds playing ‘treasure hunt’ digging for my sweetcorn seeds.
I like to grow my sweetcorn through weedguard. There are a number of benefits in doing so. The fabric will keep the soil warmer. It will retain moisture, which is important as sweetcorn does not enjoy dry soil and therefore needs regular watering, and it reduces the effort of weeding.
When transplanting sweetcorn, I cut a cross in the weed fabric just large enough to enable me to make a hole in the soil to plant the seedling. Once I plant the seedling, I give the soil a good firming and plenty of water.
It is recommended to plant sweetcorn in a grid formation, rather than a row, as this maximises the chances of cross pollination by the wind. I leave a spacing of about 30 centimetres between plants in all directions.
Sweetcorn swaying in the breeze on a hot summer’s day is one of the joys of the season. Unfortunately, it is also a signal to the birds that a delicious meal is nearly ready for them. I have heard many stories from allotment neighbours of how their sweetcorn crop has been totally destroyed by birds.
The best and most reliable solution is a large net. I support the nets using long bean poles and repurposed clothes pegs. Sweetcorn typically ripens in late summer, and until the ears of corn have formed, there is no need to protect them. This timing makes it possible to reuse any nets you may have used to protect your fruit earlier in the summer.
Birds are not the only threat. Mice, rats, squirrels, and even badgers may also want to steal the crop. If this is a problem, try securing the net around the bottom with pegs or bricks. Some allotmenters even try covering the developing cobs with cut water bottles to stop pests getting to them.
Sweetcorn is at its most delicious cooked and eaten as quickly as possible after being picked, as otherwise the natural sugars within the corn turn to starch. I stick my sweetcorn straight into a large pan of cold water. As soon as the water boils, the sweetcorn is ready to eat. A real treat to end the summer with!
The main decision when growing sweetcorn is choosing the right variety for your growing conditions. Sweetcorn comes in three main colours: yellow sweetcorn; white sweetcorn; and bi-colour, that can be a mixture of white and yellow, or even purple.
The colour is less important than differences in sweetness level. Again, there are three main types: normal; sugar enhanced; and super sweet. On colder allotments, it is better to grow ‘normal’ sweetness level varieties, as the ‘super sweet’ varieties require a longer growing season and more heat.
Choose one variety to grow, rather than a mixture, as this will avoid accidental cross pollination.