In (American) English, garlic is both the singular and plural. I have garlic. I have lots of garlic. I have two bulbs of garlic. It's never really "garlics". We denote more than one using descriptors, without changing the actual noun. This is a strange example, but pertinent, given I would be lost as to the translation if I had more than one bulb of garlic if this is the common way to do it, in Romanian.
I think the tricky part for me is that in English, I'm pretty sure, "garlic" is a non-count noun. We would say, "there's too much garlic," not "there are too many garlics." Recipes call for two heads, bulbs, or cloves of garlic, but not "two garlics." The only time I can imagine it is if one were taking about different varieties, as in "that store sells four garlics!"
I get what you're saying. You'd just say X garlics just to simply things sort of like you could ask for X cloves or X bulbs in English without specifying garlic once the context is there. Aiming for a direction translation in this case would just be tricky, like you said.
Good to know. I guess that's better than "one garlic/two garlics," although I think that "clove/cloves" is more specific than "un usturoi, doi usturoi" and would translate to "un cățel de usturoi/doi căței de usturoi."
"un usturoi, doi usturoi" could be "o căpățână de usturoi/două căpățâni de usturoi" (a garlic bulb or head of garlic).
EDIT: Something interesting about "usturoi" is that it is derived from "a ustura" = "to burn" as in to cause a burning sensation or heat, or "to sting" as in a nettle can sting.
"a garlic" is wrong in English, because garlic is uncountable, with neither a plural or singular. (Think of trying to count grains of ground garlic.) "A bulb" is correct in English, and "A bulb of garlic" is enough to distinguish the garlic bulb from other kinds of bulbs, like tulip bulbs