Why aren't my seeds germinating/sprouting?

[BayLeaves]

I've planted lots of seeds in trays of compost in a spare room, and covered them in cling film. A few of them sprouted up with in a few days but some of them it's been 2 weeks now and still no sign of life. It's marigolds, dahlias, cucumber and tomato seeds. (The ones which have popped up nicely are cherry tomatoes, and some flower seeds called "mystic merlin")

Are some seeds just really slow? Should they be in a dark or light room and how wet should the soil be? Am I right to have them under plastic and cling film? Could the seeds be 'dead' if they're too old?

[handslikecowstits]

Things to consider:
How old are the seeds? If they're old and dried up they either won't germinate at all or it'll be sporadic.

How warm is the room? For tomatoes the temperature ought to be above 21c.

How moist is the compost? It should be moist not wet which means it should feel damp but shouldn't leave a residue on your hands when you press it.

How did you sow your seeds? Generally, the bigger the seed, the deeper it seeds to be sown. So, cucumber seeds which are big, ought to be sown at a depth of 1cm-ish. A very small seed like lobelia, should be sown on the surface of compost which has already been tamped down.

Regarding the cling film, the moisture you're generating might be too much if the soil is already moist AND if the room is already warm. Chillies and peppers need a high germination temperature so I put my seed tray into a roasting bag to help them germinate. My other seed - tomatoes, cucumbers and flowers seem to manage without this.

Also remember, some seeds take longer to germinate than others. If your room is warm then take the bags off and check to see how wet the compost is.

My personal bet is that your seed is old. How did you store it over the winter? Is it new? What's the sell by date on the packet?

[handslikecowstits]

The residue on your hands - I mean water left on your hands not compost.

[handslikecowstits]

oh and the majority of seeds need sunlight.

[Cathpot]

I've given up on soil now and scatter seeds on damp kitchen roll in a Tupperware with the the lid resting on top and leave it on windowsill by the sink so I see it every day and don't forget to keep it damp ( the danger is it does dry out really quickly). They germinate really well and then when you need to pot on you can get the paper really wet and it falls off them, or just plant with paper on roots. It's so much less faffing about.Having said that I've only tried cucumber, tomato and chilli ( and a random apple pip) so I don't know if works for everything.

[shovetheholly]

2 weeks is early days, especially if your room is on the chilly side. I would wait a little longer before deciding that they're definitely not working!

All those seeds like light and relatively warm temperatures - 18-21 C should be fine. They should be kept moist but not waterlogged and sodden.

Sometimes with old seed things don't germinate. But that's also true of new seed - I sowed a couple of packets of cauli seeds on the same day a while ago. One set has germinated terrifically, the other is nowhere to be seen. Since they've been in identical conditions, I can only assume the major difference is the seed itself.

I am actually finding I get MUCH better germination out of seeds I've collected myself than ones from the garden centre.

[BayLeaves]

Still no sign! I'm disappointed Might just buy some starter plants instead!

[shovetheholly]

FWIW, my tomatoes took about 21 days to emerge. Some varieties even longer.

Last year, I sowed loads of pole beans and none of them germinated. So I sowed another lot. Still nothing. So I impatiently bought some plants. Then the first lot came through, AND the second lot. I was overrun with bean plants! DO NOT BE ME!