If you want a lush garden full of vibrant plants and flowers, you might think it's just a matter of planting them and waiting for the rain. Or... do your plants also need a little fertilizer now and then? And can you actually give them too much? After all, nitrogen is a fertilizer, but isn't too much nitrogen in the air causing problems for plants? VUB plant ecologist Harry Olde Venterink breaks it down for you!