we grow both of them. The leaves on the chesnok will be thinner and more pointed upward. The roja leaves will be wider and more relaxed.the chesnok does not have a tightly coiled scape and the roja will.
The garlic lady

My Spanish rojo looks likes small elephant garlic and the bulbie capsule produces larger bulbies than others hard necks for me, if I let them go that far. My roja also produce a some what artichoke bulb, unlike my purple stripes which have a row of cloves around the stem.

Dustin

Thanks for advice. i don't quite have the tight curls on what i think may be Spanish Roja, but i do see much larger bulbils on the scape. i'll learn to label things/make a better map this year. Thanks again.