"legal" faux cocaine. What is this called?

A good friend of mine told me the other day about some new legal "drug" he's been taking that imitates cocaine. Some sort of plant food or something to do with making plants grow (that's what it's technically sold as), but I didn't catch the name. A few months back, he told me about this legal marijuana like substance called spice that is technically incense he was smoking. After I did a little research into it, I found out it was pretty dangerous. It took a little convincing, but he eventually stopped smoking that crap, and now he's moved on to snorting plant food to get high. Spare me the speech about not ociating with him anymore, he's been my good friend since childhood, and I hate to see him destroy himself like this. He went through rehab a year ago for coke addiction, and he stopped doing illegal drugs because his rehab drilled it into him how dangerous they were. Unfortunately, he umes these imitation drugs are safe because they are legal (even though smoking/snorting them are not their intended uses). I tried to explain to him that just because it's legal, it's not necessarily safe to ingest. I tried comparing that rat poison is legal, but you wouldn't take that. However, he said if I could show him it was bad, he'd stop. If anyone knows what this is called, I'd appreciate it so I can once again research it and convince him it's no good to ingest.