Sweetcorn germination tips required please!

[Deb P]

I'm having problems this year getting my sweetcorn to germinate.

I'm on my third lot now, growing two varieties 'Earlybird' (Ha!), and 'Kite', both lots have 0% germination rates. Fresh seeds this season, but they do look quite wrinkled and dehydrated, I don't remember others I've sown in the past being quite so 'wrinkly'.

The past two lots were in indoor propergators, this has worked in the past, and for everything else I've tried so far, but this seed has just sulked and rotted; what am I doing wrong this year? I vaguely remember someone mentioning they germinated sweetcorn sitting on the surface of the compost, but can't find anything on the search of the forum, worth a try?

[Chantal]

I pushed mine into modules in one of those greenhouse trays that comes with a plastic cover. This I kept in my heated greenhouse. About 50% germinated and I took the cover off but kept them in the greenhouse. Once these were a few inches high and there were no signs of the others, I pushed in some new seeds which all appear to have come through. I've moved them into the unheated greenhouse now and they're doing OK but need a lot of water.

[Anonymous]

There was a tip in either April or May KG to barely cover the seed with compost. That planting too deep causes the seed to rot off. I can't remember where in the magazine it was, and the only reason I remember it is because we have had difficulty in the past getting corn to germinate, and we were going to try it this year.

valmarg

[Deb P]

That might be what was lurking in the old memory banks, I couldn't remember where I saw it, I'll go and try and find it in the magazines , thanks.

[jane E]

You can get sweetcorn coated with that red stuff which is supposed to aid germination and you have to be careful handling it. I seem to remember that seed from Nicky's seeds came coated. I doubt whether it's organic. However I got good germination with it. I expect someone will have the technical knowhow on this.

[Deb P]

The seed I had last year were coated with that 'red stuff', I presumed it was a fungicide of sorts. The seed I have this year hasn't got any visible coating on it, I wonder if that's a factor in why they haven't germinated as well?

[pigletwillie]

I plant mine about a half inch deep in individual 2" pots (40 to a tray from Aldi). These trays sit on the second shelf in my heated greenhouse (12 degrees) until germination when they are moved to the top shelf.

Germination rates are above 90%. I planted 160 seeds and some 145 have come up.

If you plant them in propogators with lids I found that they hate the humidity and rot. Give them fresh air and not to much water and they romp away.

The varieties by the way are Lark and Swift. I grew Lark last year and it performed very very well indeed.

[John]

Hello Deb
In past years I have pre-germinated sweetcorn seed by simply leaving it on several layers of very damp kitchen towel folded into the bottom of a large marge carton. I left them on the kitchen windowsill. As soon as the first root appeared I potted them up individually and they grew on fine.
I not saying that this gives you a better germination rate but at least you can see what's going on and don't waste time and compost potting seeds that never come to anything.

John

[Johnboy]

Hi Deb,
You will probably remember me harping on about people using propagators unnecessarily well I think this is a case in question. Sweet Corn, although needs to be sown later than many other plants needs at a reasonable constant temperature and only around 12C. Once the seed has been activated with moisture it really doesn't need any more water until it shows from the top. Sweet Corn is another seed that can be sown scar down, as John may have observed, that the root appears at the side of the scar and growws straight down and the seed carries an enormous reserve of food. About 95% of a Maize Seed is a food sac. The compost only need to be moist and no more.
I sow by simply pushing the seed into moist compost about 1/2" (a la Piglet) and when I have finished the tray simply bang the side if the tray a couple of times and await the top growth. I have very good germination rates bodering on 100%.
I think if you are having difficulty to adopt John's method may reassure you.

[Garlic_Guy]

I grew sweetcorn for the first time last year, so am definitely still learning.

Though this doesn't answer your question on germination, I started mine in Roottrainers. They all did really well and were the thickness of big spring onions by the time I planted them out.

We finished off with a good crop. I remember Johnboy mentioning about minimal watering last year (on the old forum). I took his advice and after they'd been in the ground a week or so and got growing, didn't water them at all.

[Geoff]

I would have thought you have also started too soon. I know I'm cold up here but I don't sow until the first week of May and even then plants can be a bit big by the time they go out. I use individual 8x8x12cm pots, soiless compost, just push them in ½", heated greenhouse until they show then cold greenhouse. I grow Northern Sweet, some in cold greenhouse rest outside with the squashes etc with a windbreak fence round the bed.

[Chantal]

Everyone keeps saying that sweetcorn don't need much water, but mine are asking for loads. They wilt if I don't water them every day. Also, is this supposed to be before they develop the corn? As the corn heads are mainly water, surely they need a lot? I'm confused.

[Tigger]

Nothing new there then Chantal!

As for watering sweetcorn - I've always found them thirsty things.

[Johnboy]

Hi Chantal and Tigger,
Of couse they need water!! If you read what I have said they do not require very much to germinate and they do not really requre water until they show above ground. You are both talking about growing plants, which may I respectfully remind you both is not the subject under discussion. Consider both of you to be on a yellow card!!
However, what you are saying is perfectly true, they are quite a thirsty plant but even then too much water can give good but fleshy plants that do not yield as much as they might. Also too much water encourages shallow rooting which in the case of tall plants, as they are, becoming prone to wind damage.

[Chez]

I'm with you Geoff. I would have thought it was a little early and we are in East Midlands. We won't be sowing sweetcorn until next weekend. In an unheated greenhouse. The rationale (well, OH's) is you work back from when you want to plant them out so you don't have them sitting in trays/pots, etc., any longer than three weeks. We sow as others do - 1/2" below the surface, etc. Germination has never been a problem - about 90-95% every year. Mind you, you are not 'supposed' to sow in seed trays as it disturbs the roots when transplanting and our very best germinations and subsequent crops came from those sown in seed trays. The modules were slightly lower, but still around 90%. So who knows? We are using rootrainers for the first time this year, so that will be interesting. Maybe.