I waited until my tank cycled before I added plants. I don't know if amonia will cause plants to die.
That said, not knowing the answer to the question above, we need more information. What type of lighting (T5, CF, MH) do you have and the photoperiod?
What type of substrate?
What type of plants?
If there is anything I learned its patience, patience, patience. I had plants that I thought were dead - several weeks later they started growing like a weed.
I've had plants that others said were easy to grow, die no matter what I did.
I've grown plants that were said to difficult without a problem..
So, patience.... and what works for others may not work for you. Go slow, make suttle changes, see what happens, make a nother suttle adjustment, etc....
*Substrate = 50% Florite sand 50% regular Florite
*Lighting 108W of a 216W T5HO Aquatic Life hood 25" from substrate 8.5 hours daily.
*Amarath Redroot, Waterhyssop, Brazilian Pennywort, Water Wisteria, Jungle Val, Moss Ball, Riccia, Nana, Java Lace, Cryptocoryne, Pigmy Chain Sword.