The 2 most common causes of stunted growth and plant death are (1) over-watering leading to root rot and (2) lack of nutrients.

You don't mention what size "cups" these couple of inches tall plants are in and small plants in big cups are easily over-watered. And you don't mention anything about feeding or fertilizing them either. If they are over a month old and have developed true leaves then they very likely need to be fed.

Top growth shouldn't always be the focus either - root development is what is important. Plants grow in cycles so it is very possible that they doing just fine and more patience is needed.

Dave

They're in a small sized styro foam coffee cups. I transplanted them from starters I made and transplanted greatly and kept growing until a month ago.

Being under lights I had to keep up with watering daily since the soil dried quickly. Now being outside I have to less water ( they get about 4-7 hours of sun), Only a few times soil was more on dry side outside.
My smudging sage quit growing too in the cups at same time and the mint. Yet everything else keeps growing... peppers tomatoes etc..
I just find it odd.
I don't remember which plants but 2 or 3 out of the 4 flowers I am growing all the research I did said they aren't picky with soil and can grow anywhere. I'm also growing poppies and different kinds of sunflowers. Poppies I just sowed into the ground. Sunflowers are doing great in cups and ready for ground.

So maybe they want more food. I only started those indoors because we have a global cooling this year and I'd like to see some blooms this summer.

PS... the roots aren't so great on a couple I've seen when watering... a couple washed up and the roots were only about an inch and I had to rebury it in the cup. I would have assumed a greater root structure.. but I've never grown flowers from seed before.... I don't know.

Being under lights I had to keep up with watering daily since the soil dried quickly.

Watering daily? Sorry but even smaller containers than the cups you are using and even under lights, daily watering is very uncommon. Maybe every 2 days. The soil may appear dry on the surface but it isn't dry down at the root level. It is better to go by the appearance of the plants - any drooping leaves, any loss of turgidity in the stems - than by the soil appearance.

Most inexperienced growers are way over-watering, even when they are convinced they aren't and stunted root development results.

So maybe they want more food.

What food have you given them and how often? A diluted solution of a well balanced fertilizer weekly is the common recommendation. But given the poor root development I would mak it any stronger than 1/4 normal strength.

Are there drain holes in your cups? There should be and if so then bottom watering is always better than top watering.

Dave

Dude.... the soil comes dry to a crisp under lights with a small amount of soil. It requires most times daily watering and YES... plenty of holes for drainage and there's a little bit of water in the pans for them to soak some water up.

I haven't use any food for the starters... I used decent potting soil.... never been a problem with anything else but these I mentioned above... and mint is hard to grow period in pots.

I SLOWLY introduced them to light... started with shade in the evening.. 20 minutes each for several days... brought back to lamps.... introduced more sun... quit growing. I've followed the rules by professionals... done so same with many other types of plants and not a problem.

Has anyone experienced what is happening here???? I surely can't be the only one. I don't know if my thread got in the right Colum.