i planted 15 seedlings which i grew myself 6 days ago i have 3 left the rest compleatly dissapeared no slug trails nothing can you help

You don't say what type of seedlings but the most common reasons are birds and rabbits!

On my allotment I have to cover all my seedlings with nets!

This year the plots are being over run by rabbits,although in the past it was pigeons.

Flying slugs?

:^)

Sometimes slugs and snails manage to leave no trails so it would be worth putting pellets round the three you have left and putting them somewhere off the ground and near the house if they are still in pots - that should deter all three possibilities. Or if they are in the ground another ploy would be to cover them with something - one of those plastic boxes that supermarket meat comes in for example. Heap a bit of soil round the edges so it doesn't blow away, and put your slug pellets inside it where nothing else will be harmed by them. If they are tall eg cosmos use empty water bottles with the bottoms cut off - leave the stoppers off. (These also make good mini cloches for sweet peas if you want to plant them out a bit too early)

All of my pea sprouts disappeared overnight once, leaving nothing but little dents where they had been...
...the culprit was a mole...

My peas I sowed in the polytunnel early in the year were almost all taken like Karenfrance's, with just a little depression at each point. Those that survived and began to grow then were nipped off at ground level. I put down a mouse trap and over two nights caught three 'mulots' or field mice which had tunnelled into the tunnel! I think moles would be after worms as they are carnivores, or perhaps one of Karen's neighbour's referred to a 'mulot' which is a mouse like rodent.

Seems the plants are marigolds but we don't know what type - French, African (Tagetes) or English (Calendula)? How big were the seedlings, did you plant them in the ground, and where had they been before you planted them out?
If they were French or African marigolds (Tagetes) these are half hardy - if you grew them inside or under cover, didn't harden them off and planted straight out, the cold will have killed them. If they were small seedlings, not hardened off, the weather is so bad they may have been killed anyway because they were too small to cope with the bad conditions. If they were English (Calendula) they would still have needed hardening off before planting outside if you grew them inside.

Aha, Bertie...the neighbours would have called it a taupe...must have just been coincidence that there was a mole at the same time!

Didn't notice it was marigolds. If they were hardened off as Bamboo says it was pretty sure to be slugs or snails then - I can't keep African Marigolds longer than a few days before they are half eaten and they never thrive after that.

French marigolds seem to be irrististable to slugs.

I bought a tray for a customer last week and they ate the lot