I have the same thing on my plants. It appears to be just type of tomato and from what I have found out from the local extension office it is just part of the growing trend.

leroifl, what kind do you have? I have some celebrity and some sweet tangerine (orange type from burpee). Before anyone jumps in to tell me celebrity is not worth growing... I am growing determinants because my yard only gets 5 hours of sun and I am just testing to see if any tomato would grow.

Mine did the same thing. It seems they are losing the red now that they are a few weeks old. I have read that it is from either cold temps or too close to lights, and it leads to the plants having trouble intaking phosporus.
Or something like that :)

It's always been normal for me and the cooler temp. is the cause. Most people consider,myself included, them to be "purple"...except when I'm wearing my yellow tinted sunglasses. I prefer to keep my seedlings cooler (between 50-60 degrees) so that they develop more roots and end up a much stockier plant. They'll turn green when they warm up.

Perhaps the seedlings are making the red to absorb more far-red light for some reason - ecological advantage, light too far away, varietal characteristic. Red undersides in forest understory happens all the time for absorption of far red light. Just a thought.

If it is more purplish this is an indicator of micronutrient deficiency, maybe potassium; as you haven't said what medium they are growing in, whether you've potted them up, fed them, it is a troubleshooting item that can't be checked off either.

Dan

Do they look like this?
{{gwi:31511}}

Mine always do, including the one's I have going right now. Yours are looking nice and normal with good root development. They should plant out just fine.

I honestly would say it is a deep maroon color. Not really a purple. They are potted in jiffy seed starting mix in plastic drink cups. I fertilize them with 1/4 strength tomato fertilizer once a week. The drinking cups are red... fwiw. It is about 70 degrees today here in virginia so I put them outside. They seem pretty happy. :)

I've never had that color AFAIK. Certainly not this year, and last year I used those pellets. I just did another round 3 days ago so I'll check again. That piccie doesn't indicate any deficiency that I can see from here.

Dan

Purple leaves in seedlings (as opposed to full sized plants) is common and essentially normal. It is caused by the stresses of growing. More common in some varieties than others, somewhat related to cooler temps which can't be avoided, not a deficiency problem, and disappears as the plant grows and adapts. Don't worry about it.

We used to have tons of discussions here about 'purple leaves' as it comes up several times each spring but search doesn't find them now. Guess most of them were bumped off. ;)

Dave

Our tomato seedlings have been robust and transplanted to larger containers about 2 weeks ago. Have moved them out of the "nursery" to begin harding out for several hrs/day about a week. Then temps and weather made us move them back indoors. Since then, they have had slightly wilted leaves and look like they have stopped growing. Gave them 1/2 stregnth fertilizer. Suggestions?

I am also having problems. Nice true leaves, but now the tips of the leaves are turning brown?