Sunday, 1 May 2011

Sweet(corn) Nothings

Let's talk sweetcorn. Am I just rubbish at growing it or is it a somewhat testy diva of a vegetable that swoons when the conditions are anything less than perfect?

Last year I started the seeds off at home, outside in small pots. I reasoned that they'd grow already accustomed to the ambient conditions and I wouldn't have to bother hardening them off. This meant that they were outside during the late frost we had at the end of April last year, still tucked up under the potting compost in my sheltered, relatively frost free garden though, so not catastrophic. However, I do wonder whether this may have stunted them in later life.

I found that, at every stage of the growing process, I seemed to lose a proportion of the plants/ears of corn. About half of the seeds actually germinated and their progress was slooooooow, about 3 weeks from sowing to green shoots. Of the germinated seeds probably one third failed to thrive and didn't produce any corn. Of the plants that actually grew, about half produced decent corn and the other half produced weird nearly naked cobs. I think in the end we only had 6 or 8 decent decent cobs of corn from 20 plants.

This year I decided to buy a bigger cold frame so that I had the room to start off all my seeds under cover and get a head start. The sweetcorn has germinated within days but still, half the seeds have failed (in stark contrast to everything else which, other than the disappointing Mr Stripy tomatoes, has a success rate of almost 100%). I can also see huge disparities in size between the plants, a few are large, vigorous and obviously healthy (as seen in the photo, mid sprinkler session this afternoon) but a handful are rather runty. The pattern of last year seems to be repeating itself already.

So - what's your experience? Is my allotment fundamentally unsuited to sweetcorn, or is this fairly typical? I'd love to hear your stories and tips.


  1. I have had a good germination rate with my sweetcorn the past two years but prior to that absolutely nothing!!

    So what have I done different these last two years?? Well for a start I have potted them up in a good compost and kept it wet at all times and also i have grown them in the greenhouse...yes you have the hardening off process but I find that it pays off in the end. I had the frost problem last year as my corn was outside hardening off and they all appeared to have died so I sowed more seed but they did all recover and so I had plenty of corn. Also corn needs to be planted in a square shape as opposed to in a couple of long lines as the cobs are germinated by each other and this helps the process along with the winds. I have planted out 49 plants this year and so far it's looking good. I don't know whether any of this will help but we had such wonderful sweet corn last year I really hope you don't give up on it because we had never had such beautiful tasting corn!!

  2. Thanks for the info. I should have said they were planted in a square. I have fewer plants than you though, about 24 I think. What do you call a 'good' germination rate?

    Someone on the allotment next to mine has planted a square of corn, I'll keep an eye on her and ask for some tips if they look like they're doing well!

  3. A good germination rate is 50%... though mine has exceeded that this year but I always plant double what I want...I figure I can gift them to other plotters if I don't have room for them all!!

  4. we sprouted our sweetcorn in water before potting and putting in the green house. this meant that we could see how many corns had germinated and helped us plan how much space to give then in the allotment. of 50 37 germinated, but it looks like a few have been lost at this stage too