My clementine seedling doesn't seem to be growing new leaves, it sprouted around early/mid-may and grew one true leaf and then it stopped. What is wrong with it, it is potted in a 4 inch. pot with tropical mix. I just don't know whats wrong with it.

If your plant sprouted in May, it's behaving quite normally. Citrus normally grows in "flushes," interspersed with periods of dormancy. And after the first true leaf or two, a dormant period normally occurs. Just keep the plant healthy and it will grow again, probably in the next month or so.

To my surprise the seedling is starting to get a second true leave i am excited now, can i start to fertilize it now or should i wait?

I grow approximately 50 -100 Clementine seedling every year. Clementine seedlings will not produce true from seed, but rather a one of a kind never seen before variety. Almost every seedling tree will turn out to be of inferior quality. However, many of the now famous citrus varieties came about as a chance seedling. I grow them for the fun of finding the MIRACLE tree. They will take about 5 - 6 years before the tree begins to produce flowers, but when they are grown inside a warm greenhouse throughout the entire year, the fruiting time is cut in half. After the tree has produced it's first two true leaves, you can begin to fertilize at 1/3 to 1/2 strength. Good luck. - Millet

thanks it wouyld be neat to find the perfect fruiting clemtine, now i am really excited bcause i have two seedling the other one is older but still has its seed leaves i guess i will have to wait.