So one of the seedlings I transplanted into a bigger pot has developed gray veins and a gray rim around its leaves. It is also causing the leaves to fold up like a taco.
Any thoughts on what this could be?
Stress. Weather on the cool side. Perhaps too much water.
(Lovely pictures, BTW.)
To be able to suggest what might be wrong with your plant, it would be helpful to know more about the environment it is in. So, here are the "usual" questions:
What growing medium are you using? How large is the container? Is it self-watering or do you manually water it? Is the container in full sun, part sun or shade?
It would be helpful to know these things as well: How often do you water? Have you checked the moisture of the growing medium or soil 3-5" below the surface? Is it dry, just right, or soggy? Are you feeding the plant? How often? What are the NPK values of any fertilizers you are using to feed it? What has the weather been like in your area?
The more information you can give us, the better the chances that someone can give you an accurate diagnosis.
Plants were potted up into gallon pots with 90% potting soil 10% compost 5 days ago when I bought them in 4" pots. They were a little root bound and were pretty tall so I pruned off the lower branches and buried them deep in the gallon pots. Moisture level seems to be about right.
Container is in full sun, has been mid 70's all week here in sunny california, nights anywhere from 50-60F
The purplish / grey veins look like a phosphorus deficiency. Did you fertilize when you potted up? I might dry the plant out a bit and add a little bone meal and then water with a soluble fertilizer while they're waiting to be transplanted.
I try to grow all my plants from seed so I know what the plant's environment was like the whole time. But sometimes I'm tempted by pineapple tomatoes and ghost pepper plants at my (very reputable) local nursery and I like to transplant into a medium with mycorrhizal fungi as a prophylactic. I also use a foliar spray of worm casting tea, aspirin and kelp meal. An ounce of prevention...
Why are you assuming some sort of virus? Based on the info so far and the pics the odds are 9:1 it is nothing more than environmental and transplant stress.
When you bought them were they hardened off? Why are you using potting soil and compost in a container? Plus you pruned them and they were already root bound? Sounds like a heavily stressed plant to me.
My guess is also, transplant stress combined with fert. deficiency. They'll be fine with a little action.
"...gallon pots with 90% potting soil 10% compost"
The soil is probably responsible for your issues. You should never use potting soil in a container. It's too heavy and does not drain well enough for containers. Always look for a soilless potting mix. The ones that say soil on them are usually labeled that they are not for use in containers.
Are you potting up again, or is that the final home for your tomatoes? Most growers recommend a minimum of a 5 gallon container for growing tomatoes in containers.
All in all, I think if you get them into larger containers (if they are to be container plants) with a quality growing medium they will snap out of it. They have been badly stressed, especially if they were not hardened off.
I hope that helps.
Agree totally with bets. I was about to post the same info.