You could be overdoing the ferts/water bit. Too much is at least as bad as not enough.

Hi Nick,

Yes it is normal for the cotyledon leaves to yellow and fall off. You don't need to cut them off, but if they bother you, of course you can do so.

As garf said, to much fertilizers can cause problems and using ferts on seedlings is a common mistake. The food that is available in most growing mediums is sufficient to carry seedlings through to the 6-8 weeks until they are ready to plant out into the garden. I'm thinking that if you are in zone 9, that should be PDQ for you, shouldn't it?

If you seedlings are still in a soilless seed starting mix (one that is labeled specifically for starting seeds) they will have exhausted any nutrients in it and need to be potted up into a standard soilless growing medium or transplanted into their final location.

The FAQ page linked below gives a lot of good info on growing seedlings.

Betsy

Here is a link that might be useful: How do I start tomatoes from seed?

Thanks for the answers! I was trying to remember if the seedlings I have bought before ever had the cotyledons on, but I couldn't. But they usually don't, huh?

I'll cut back on the fertilizers unless I see something wrong. Yes, I am in Zone 9, so we are supposed to be able to plant out tomatoes in a few weeks. But if these nasty rain storms and 45 degree nights keeps up like they are supposed to, I might not get them in for a month. Then I'll have to worry about the seedlings getting root bound.