Can You Please Help Identify the Problem - and Solution?

[rnewste]

Just when I thought everything was going fine (weather is 72 degrees now and the seedlings are 6" high), I got home today and found this on several of my tomato plants. Also, noticed yellowing beginning at the base of several leaves:



I have these in Miracle Grow Potting Mix with Moisture Control (but I have not added any fertilizer). I mixed in a small amount of Dolomite when I planted these guys on Feb 11. Using my moisture meter shows water content is in the "green" area of the dial:



This tan spotting condition has literally happened in the past 24 hours, as they were all fine yesterday. I'd appreciate any help in corrective action that I can take.

thanks,

Ray

[dcarch]

1. It is possible that someone else was spraying herbicide in the area.

2. It's possible that you used an old bottle which had some strong leftover chemicals.

Can you show the bottom of the leaf?

dcarch

[bcday]

Looks like a touch of sunburn to me. They'll outgrow it, but the brown spots won't turn green again.

[rnewste]

Hi all,

Seems I did something dumb! I had the seedlings enclosed in a EB with a "cold frame" type cover since moving them outside 2 weeks ago, then I took the cover off 2 days ago to give them direct sunlight. I didn't realize that they could get a sunburn so quickly.

So I have now put the "cold frame" back on the plants. Hope I haven't done too much damage.

Ray

[bcday]

It would be better to keep the cover off, but keep the plants in the shade for a few days unless the weather is cloudy. After that, give them only early morning and very late afternoon sun for a while.

It's the bright sun from mid-morning through early afternoon that does most of the damage to young seedlings, so they shouldn't get any of that until a week or so before they're ready to plant out in their permanent growing places.