This heritage variety of corn could potentially be the holder of the title of ‘most shared vegetable’ on Instagram. A few years ago they became an internet sensation when pictures of their vibrantly-coloured cobs began to circulate. This unique strain is a selection created by corn enthusiast Carl Baines. He first started to collect and grow old corn varieties as a way to reconnect with his Native American heritage. There are lots of very colourful old varieties of corn but, through careful selection of the most colourful cobs, Carl was able to develop this rainbow-coloured variety. This variety is a ‘flint’ type of corn, so is not usually eaten as corn on the cob, but is often dried to be ground into flour, or can also be used for making popcorn. It has gained a bit of a cult following in the United States, and understandably growers in the UK were also keen to give it a go. In 2014 I was able to find a UK based source of the seed so was able to try it for myself.
How do you grow it?
Initially, I only had a few seeds. As I couldn’t risk losing any, so I started them early in a heated propogator. They were sown using a good quality, peat-free compost, in deep modular cell trays, called ‘root trainers’, around 1cm deep. They were kept warm and moist and within around 7-14 days the first shoots broke the surface. Every time I have sown them since I have had approximately 80-90% germination. The plants developed quickly and were ready for hardening off in a cold frame during April. They were ready for planting out at the end of the month when the threat of frost had passed. I grew the first plants in a large pot on my patio so I could keep a close eye on them, but I have since started growing them on the allotment. It is best to plant them quite closely, in ‘blocks’, as they are wind pollinated. They grow best in a fertile soil in full sun, and appreciate a good soaking to help them establish, but are generally fairly trouble-free without any problems from pests or diseases. Once plants reach about 1.5m, the male flower will emerge from the central stalk, and the female flowers, which look like fine hair, emerge at the base of each leaf. It does help if you take a male flower and brush it over the female to ensure they have contact with pollen, but not absolutely necessary . They will flower slightly later than most modern varieties, so there shouldn’t be too many problems with hybridising with nearby plants, but it is a good idea to grow them as far away from other varieties as you can, so they don’t hybridise. The cobs are ready to harvest when the leaves surrounding them start to turn yellow. Normally this doesn’t happen until at least mid September, and often there will still be some to ripen in October. The cobs can be twisted away from the main stem, and then its time for the fun part – seeing what colours you have.
Would I grow it again?
It is very similar to other corn varieties to grow, but being a flint corn, it does take a long time for the cobs to fully ripen and the colour to develop. This means it needs to be started early, grown in a sunny location, and left as long as possible before harvesting. Each plant gave around 2 cobs, although not every cob ripened. I used the cobs that had not fully ripened (they appear almost grey) as you would sweetcorn and simply boiled them. As the sugars they contained had not yet been converted into starch, they were actually pleasantly tasty. As yet, I haven’t made any corn flour or popcorn with them. I am still trying to select the best coloured and earliest ripening cobs, and I have been swapping as much of the seed as possible with friends to see what results they have. I’ve now grown it for three years and will definitely be growing it again next year, if only for that excitement when I peel back the husks for the first time and see the amazingly colourful kernels hiding inside.