Sweetcorn - unpollinated cobs

[Demeter]

I pulled up the sweetcorn plants today and as I was checking them over to make sure I hadn't missed any eatable cobs (not quite wishful thinking - I found one!) it seemed that there were lots of undeveloped / unpollinated cobs i.e. seemed like there were 1 or 2 of these on every plant just about.

(There were also a few cob stumps where the cob had been completely eaten by earwigs and/or woodlice, although obviously I don't know if they ate undeveloped ones or what.)

I haven't been counting, and the veg is shared out anyway so I don't know exactly how many cobs we had altogether, but I reckon we probably had one good cob per plant, or near enough anyway. So I don't feel too hard done by as I believe 1 cob per plant is within normal expectation.

My question is - why did so many cobs fail to pollinate and develop? Is it because the plant is only capable of supporting one cob so if there are more they just don't develop? Is it because the pollen is only available for a short time so any silks that appear too late won't get any? Is it because we planted them far too close together (which we did)? Or what?!

NB no idea what variety they were, they were bought as plants from the farmer's market, so probably not any expensive F1 types!

Any thoughts greatly appreciated, so I know what to do differently next year if necessary. Thanks!

[squashysu]

cor for once i may be able to help someone LOL!!!

I only planted 6 plants in a block and they turned out great, a couple were half polinated, what i did do was a bit of "self polination" every time i passed them and this did the trick, i know they say for the wind to do this, but only having a few plants i needed to offer them hand. I even had some plants with 3 cobs on each.

Take some of the seeds and rub them into the "tassels", this really did help, the corn was very very tasty and next year i am gonna do more than 6. I also grew mine in large planters and some people said this may not work, but i received no slug damage either and i was very very pleased with the outcome.

Good luck for next year, they were really worth it!

[jonohanson]

I did what squashysu said too as we only had 12 plants, 1 cob on each plant was almost 100% pollinated but the other cobs on the plants were not, some were half to three quaters and some had just not developed much, I pulled them last weekend. I believe this is down to the crappy summer we have been having.

[pjh75]

I had 10, planted in sort of a block. Evey time I walked past (pretty much every day as I grow in my back garden) I shook the plants. In total I had 16 cobs with only one that was partly pollinated. I'm not sure if I would have had this many anyway, but I like to think that shaking them helped a bit with pollination.

[realfood]

My sweetcorn, Swift and Lark are carrying up to 3 or 4 cobs each, 2 are usually big cobs and the others smaller and may not be fully filled. This is probably because the side cobs tend to be ready for pollination later than the central cobs and there may not be so much pollen available by then.

[Two_Sheds]

I grew Swift - fabulous first 6 cobs. Full, sweet and juicy.

Next 6 - only half-pollinated. Why? They all get the same goddarn wind ! (that's just primary cobs ... I don't even bother checking the following ones, they look too weedy)

It is absolutely usual to have only one good cob per plant ... it's not a great return for the amount of space the plants take up, but fresh sweetcorn ~ what a treat. I'll always make room for some.

[Snadger]

The wind that pollinated mine blew the damm things over!

[Demeter]

It was definitely the "secondary" cobs on ours that had the trouble i.e. the ones lower down the plants. Maybe it is a simple matter of the pollen not getting to them because they appear too late / are too low down. I did shake them now and again, and they had plenty of wind, and they were planted in a block of about 24 plants... Perhaps I will be a bit more dilligent about it next year and actually try and rub the pollen on, at least on the plants near the outside of the block where I can see and reach the lower-down cobs. If it means we get an extra cob on a few plants it has to be worth a bit of effort

[vicky]

Glad you asked this, mine too had lovely primary cobs and I thought they'd all have additional ones lower down, but none were any good. I don't know if that's enough 'return' for the space they took up - plus the naughty toddler had more or less all of the good ones!
Next year I will try the manual method, but it's their final chance!

[Growem]

Geez, I was hoping that those thin cobs on the stalks were just taking their time filling out. Now I'm worried that they haven't pollinated. And that my toddler *also* got the best cobs!

[Demeter]

Geez, I was hoping that those thin cobs on the stalks were just taking their time filling out. Now I'm worried that they haven't pollinated. And that my toddler *also* got the best cobs!

I think "unpollinated" is right. My 3yo has the best ones too. The first time I managed to persuade her that the bigger ones are for the bigger people but after that she was most definite that it shouldn't work like that.

[Cutecumber]

I have tried five or six varieties of sweetcorn and never managed to get more than one cob per plant. I suspect that to get more cobs you need:

different varieties (i.e. not the quick, early ones)
a larger block (I do about 9-12) to aid pollination
better soil - mine is poor and sandy
more sunshine over a longer period - I may be in the South East, but it's still not as sunny as corn would like!

It is technically possible to get 5 or 6 cobs from a plant, but not usually from those varieties that are most suitable for growing here - unless you have really great conditions.