what about this split?

I love being in the gym but my workouts were getting really long. So, I made them a bit shorter, with this split: 1. shoulders 2. bicep/tricep 3. chest/back 4. lower body. every workout is followed by 20 or 30 min of cardio (either rowing, treadmill, or bike). every workout ends with some core. my question is this: bc everything is spread out, am i preventing myself from hitting each muscle group often enough? with rest days(and days for hiking or doing non-gym things), i get to each muscle group only once a week. i just started doing this two weeks ago, so no results yet. is once a week going to be ineffective for strength?