Purple Tomato Seedlings?

Started some tomatoes from seed a couple of weeks ago. I’ve never seen this happen before, they seem to be turning purple? Any ideas whats going on? Theyre indoors under grow lights that I’ve used previously without problem. Seeds were all started in jiffy seed starter.

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Presuming they are not a high anthocyanin variety, nutrient imbalance is the likely culprit. It can be triggered by low temperatures, generally 60 to 65 degrees. Some varieties are more susceptible than others. Kelloggs Breakfast often has purple leaves to give an example. How to fix it? Increase temperature and/or add appropriate nutrients. Phosphorus is the usual problem. Use a liquid fertilizer with high middle number, for example, 15-46-12 or something with similar rating. Mix 1 level teaspoon with a gallon of water and then apply a quart per tray of seedlings. Be careful, you could trigger damping off with too much water. If they are not losing water fast enough, give only a pint max.

If they are a result of a cross with a high anthocyanin variety, guess what? Its normal!


Thank you for the information! Some of the ones changing color are not from high anthocyanin varieties and theyre kept in a 75 degree room so I’m going to try out some diluted nutrients.