[RealLeeHimself]

I’ve been trying to grow tomato plants from seed (first time ever) and although it’s now been about 3 weeks I’m not seeing any sign that they’ve germinated. I’m going to have to do more research to see where I’m doing wrong....

[hasbeans]

Are you keeping your seed packets cool and dark when not in use?
Is the soil/compost warm enough?  Cool compost will slow/prevent germination. 

[mumofstig]

I’ve been trying to grow tomato plants from seed (first time ever) and although it’s now been about 3 weeks I’m not seeing any sign that they’ve germinated. I’m going to have to do more research to see where I’m doing wrong....

Let's see if we can help - how/where are you sowing them, and in what?

[Veg Plot 1B]

Hi I have been trying coir & small bags of compost with some success, will post pictures latter.

If you pm me your address I will put a few in the post for you to try, free of charge.

[Veg Plot 1B]

Pictures of the bags.

[Batesy]

I'm a newbie too but if it's any help this is what I did (mine germinated in 5 days):

I used 3 cells from a seed tray insert (with drainage holes) and filled them with compost before watering thoroughly. I made four shallow holes with a pen in each cell and put a tomato seed in each hole. I lightly covered each hole with compost before putting clingfilm over the top and placing them on my East-facing kitchen windowsill. As soon as I saw green shoots I removed the clingfilm.

I keep the compost moist by watering from underneath. To do this I use one of those plastic trays that supermarket mushrooms come in. I put a small amount of water in it in the morning and then stand the seed tray cells in the tray. They aren't quite ready yet but as soon as the seedlings have two sets of true leaves I will thin them out to one seedling per cell.

The attached picture is what the seedlings looked like first thing in the morning on day 5, when I checked them on the evening of day 4 there was nothing to be seen!

[Lardman]

Where did you buy the seed from ? For the second year running I've had terrible problems with germination of tomato, pepper and lettuce seeds using fresh seed from a very well known, popular and previously well respected ebay supplier.

Tomato seed should be very easy to germinate - just about any moist, sterile medium in a warm place and you should see signs of life in 5-7 days.   You shouldn't need to water after the seeds are sown, you run the risk of rot.  Use a small pot - any not just plant, fill with compost, water allow to drain then sow seed. I push them just below the surface with the wrong end of a pencil . Put on any window cill covered in cling film or a clear plastic bag, leave alone until germination.

Edit :
Here's the sort of thing I mean - it may not be anything you're doing or not doing, 8 rows of lettuce sown here.

[Goosegirl]

Like others have said, use compost (I like multi-purpose as it's not as cold as a soil-based one), tamp it down gently, sow some seeds on top, just lightly cover with a layer of fine compost, water from below until the surface is just damp, cover with cling-film then put them where it's warmish until they sprout. You can tell if the pot needs watering by lifting it up and if it feels quite light, water the pot like you did before. It may well be that the seeds are not viable for some reason and the supplier may not be aware of this unless people contact them. If in doubt, nip out to a local shop and get another packet from a different supplier. I'm late in my seed sowing and germination this year due to the cold weather so am hoping the cropping season will be later than usual.