To remove podcasts from your Apple Watch, follow these steps:

1. Open the Watch app on your iPhone.
2. Scroll down and tap on 'Podcasts.'
3. Under the 'Add Episodes' section, select 'Custom' instead of 'Listen Now.' This will stop new episodes from being added automatically.
4. To remove existing podcasts, go to the 'My Watch' tab in the Watch app.
5. Scroll down to 'Installed on Apple Watch.'
6. Find 'Podcasts' and tap on it.
7. Toggle off 'Show App on Apple Watch.' This will remove the app and its data from your watch.

Remember, this will only remove the Podcasts from your Apple Watch, not from your iPhone.