Way to get old podcasts in iTunes

Solution 1:

In iTunes, you can only download the shows that are in the show's RSS feed. For any shows beyond what's on the feed, you will have 2 options.

1. Go to the website and download each one individually.
2. Email the host and see if they can send you a Zip file with all previous shows.

Solution 2:

As far as I remember you can add them "manually" by clicking on the list. Just search for the show on the iTunes and click on the individual shows you want to download.

Edit: it seems that the iTunes store just shows episodes of the certain period.

From Apple's Support - Podcasting Frequently Asked Questions (FAQ):

Troubleshooting podcasts

I subscribed to a podcast, but I don't see all the episodes—only the latest. How come? iTunes will only display the podcast episodes that are included in the podcast feed. Many podcasts have the older episodes archived on the web. Check the podcast hosting site to see if older episodes are available.

Solution 3:

sometimes, you might delete the undownloaded podcasts from your list. to get them back, so you can decide to download them, collapse the podcast branch, then shift-click the arrow to expand it again.

Solution 4:

If the reason the podcast is missing episodes is because they’re missing from its feed, and the feed has history archived in the Wayback Machine (which many are), you can use Backfeed¹ to generate a feed which includes all current and historical episodes².

<sub>1. Disclaimer: I created Backfeed, since I was annoyed at the same problem.
2. Backfeed depends on snapshots of the feed existing in archive.org. The results will be limited by the number of snapshots available for retrieval by a sane number of API requests.</sub>