Normally no problem with hybrid seeds. You might want to ask yourself a few questions:

How old is the seed, how was it shipped, and how was it stored? All of these factors can affect germination, sometimes drastically.

How warm is the propagator, actually? Temps below 21º C will slow germination considerably. Above 33º, germination may be prevented entirely.

Has the medium been kept moist, but not soggy? Periods of drought will kill the seeds just as they are trying to germinate. Saturated soil would smother the seeds, or encourage water molds that would eat them.

Was the medium fluffy, well aerated, and fresh and reasonably clean? Too heavy mediums don't drain well enough to prevent saturation. Those contaminated with garden soil, or old, used potting compost, often harbor diseases that can rot the seeds.

Answering those questions should help you to unravel the problem.

Tugbrethil, thank you for your indepth reply, much appreciated.

OK, here goes ....

1. One packet of seed was Sutton and the other T&M - both within date and sowed soon after purchase. Not that popular varieties, so my first mistake is probably buying from Ebay but packets seemed fine and vacuum sealed.

2. Propagator in kitchen window, kitchen always at least 18 degrees, not sure of heat of propagator, its 13 watts - 7 individual seed trays, bottom heat.

3. Kept the soil moist but John Innes is quite sandy, isnt it, not fluffy, I thought it might be a bit heavy to be honest. Fresh compost though and clean.

4. Seed trays washed beforehand.

I've not done anything different to other years - maybe a combination of not enough heat and heavy compost then.

Not sure what to do now.

Thanks again, Dawn

Hi
Buying from Ebay should not be a problem if the packets are sealed and the dates are fine.I have used vermiculite and seed compost with mine and they usually germiniate very quickly around about 7 days is norm the vermiculite helps with light and keeping the soil moist
Hope this helps
Steve

formuler 1 seeds sound very fast to me dawn lol xx .

Hello Steve, I wish I'd mixed vermiculite with the compost now, thank you. I've set them the same this year as I always do so I dont understand what's gone wrong. Not cheap either and only 15 to 20 seeds in each packet.

Lol Leigh, yep, not much speed with these F1's!

Sand isn't too bad, Dawnsaunt, as long as it isn't so fine it is like silt--vermiculite probably would have helped. It is possible that the seeds were frozen in shipping. Tomato seeds can be frozen--in seed banks, they are kept in liquid nitrogen--but they need carefully controlled conditions during the freezing process. Accidental freezing may be too slow or irregular a process to prevent embryo damage.

Possibly Tug, whilst in the post? Any suggestions what to do now? Still no signs of germination. Thanks

Sadly, it sounds like it is time to buy more seeds, to me. That is, if you still have enough growing season left. If not, wait several months for next year's seeds to come out, buy them early, and keep them cool and dry until time to plant.

I think so too Tug, thanks for all your advice.