1 of 3 new plants isnt growing, what can i do?

[Carowoot]

I recently got a 60litre (15-16 gallons) tank. Got it a good filter, some ornaments and pebbles, a heater and added the water ager and stabiliser and once it was all set up and running for a few days I went and bought 3 plants for my future fish to enjoy. The two bigger plants that I placed at the back of my tank are doing well, they've grown roots etc. But the smaller plant isn't doing too well. What might have gone wrong and how could I try fix it? Thank you

 

[Sillyfishies]

I recently got a 60litre (15-16 gallons) tank. Got it a good filter, some ornaments and pebbles, a heater and added the water ager and stabiliser and once it was all set up and running for a few days I went and bought 3 plants for my future fish to enjoy. The two bigger plants that I placed at the back of my tank are doing well, they've grown roots etc. But the smaller plant isn't doing too well. What might have gone wrong and how could I try fix it? Thank you

What's lights are you running?
Co2 or fertilizers?
What plant Is it? Pic?