Tomato starts

[Snag]

Mine have been up for a few days , and I've noticed the leaves are kinda yellow . These are planted in potting/starter mix , new stuff . They spend most of the day outside when it's sunny and above 50° . I water when the soil getss dry about 1/8" deep , and the trays they're in have good drainage , so they're not in standing water . The pumpkins planted the same day are fine , as are the marigolds . I'm just wondering if this soil lacks something tomatoes need . It does have slow-release fertilizer in the mix .

[Billy]

Tomatoes don't really do much (provided full sun & adequate water) until the soil temp hits 60F (16C).

[Snag]

These trays are inside the house except when they are out on the front porch in the sun ... soil temp should be well above 60° . I'm just wondering why the leaves are so yellow - these are the first pair of leaves . Other than the color they seem to be doing quite well .

[Billy]

Sunshine, and 60F temps simultaneously, or lack of nitrogen.

[Gunner]

Just curious, first true leaves? If your plants are at the stage of needing more nutrients you might try looking into your "slow-release fertilizer in the mix" at this stage. Doesn't sound like a low threshold photosynthesis issue. Do you know how/or when the nutrients in your mix release? There are as many =93slow release=94; =93controlled release=94, or some such =93coate= d=94, usually formulae as there are companies making them. They release their nutrient(s) in different ways, some at different temps and not all contain micro-nutrients. There is no one-size-fits-all fertilizer. If you do not know about using controlled-release (CRF) and slow- release (SRF) fertilizers you could start with this article and maybe a few of the side bars from it, perhaps research the specific brand used in your mix:

[Snag]

You're over my head ... these are the very first pair of leaves outta the seed , and they're looking better now . First true leaves are just now beginning to form .

that's supposed to be good for about 3 months , I have no idea what it actually contains or how/when the nutrients are released . -- Snag Learning keeps you young !