for plants look at hornbach in Binzen, 5 mins from the basel/german highway border and baumarkt on the LH side as you enter lorrach alsofrom the basel/german highway - just contiue past the turnoff for hornbach.

As you are new in the area stick to the 80km limit when re entering CH as there is a speed camera directly after the first tunnel

for shopping go to marktkauf in weil am rhein