Slight yellowing on leaves of tomato plants?

My tomato transplants are experiencing a slight yellowing on a few of the outer leaves. It is not all plants, just a few.Last year when I transplanted, I used Miracle Gro potting soil and lost whole batchs of plants. I attributed this to too strong a fertilizer in the medium. Yellowing usually means lack of nitorgen but again this is a potting mix with some fertilizer. Cant seem to buy anything else anymore. Is there another reason leaves could be yellowing. I fertilize with worm compost tea but have not yet fertilized because I am concerned about a repeat of last year...too much fertilizer. The other leaves on the rest of the plant area lush, dark green.

Slight yellowing on leaves of tomato plants?
There are lots of things that can cause yellowing tomato leaves. Nutritional deficienties other than nitrogen can cause it. There are some viruses and disease that can cause it (most notably yellow leaf curl virus), and even over watering can cause it.



Though with overwatering, it usually start from the bottom - the leaves on the bottom will start curling up, looking a little yellow, and otherwise to the untrained eye look like they're dying of thirst. So the novice gardener waters more, exacerbating the problem.



Can you post a picture of the whole plant? Including a close up of a leaf?
Reply:Disease, probably Verticillium. Bet its starting near the bottom. Nothing you can do to save your plant, just buy disease resistant varieties next time. Could be blight but blight tends to be more brown.



Too much fertilizer is harmful to your plants also. It can either inhibit their ability to absorb nutrients or burn your plants which will cause them to turn yellow.



Enjoy what you can get out of them.

blackheads