Why are they invariably called "garden peas?" Where else would they be grown, except in plantations.......surely the same as gardens? (Understand the difference from mushy peas......but these will originally have been grown in the same place?)
We don't buy "garden beans" or "garden carrots"......so why peas????
Presumably to differentiate them from Wild Peas, Purple-Podded Peas, Salmon-Flowered Peas and many other types of pea (including Lupins, Mimosas, Trefoils, Brooms and Clovers - they're all members of the pea family!).