I had wondered how we were going to access the podcasts when I first saw this post on the Croome Walled Gardens Facebook page. Having forgotten about it in the meantime, I had a look just now and found the podcasts page on the NT website.
There are three podcasts in this series, covering Stourhead, Croome and Sissinghurst. The first has been available since 20th October 2016 with Croome available from 10th November and Sissinghurst from 1st December.
However, if you don't already subscribe to iTunes, and don't want to subscribe to iTunes, you've got a problem. If you select one of the podcast options off the NT's web page, you are re-directed away from the NT website and onto a page on the iTunes website. Although the podcasts are notionally 'free', if you want to get them you have to subscribe to iTunes, with everything that that entails.
In case I've confused anyone, you can listen to the podcasts without signing up for iTunes; it's only if you want to download a copy that you'll need to subscribe. Just press the little 'play' button (hover over the number) to the left of the podcast you want.
Nice though todays podcast about Croome is, I'm more than a little sad that the Walled Gardens (see photo) didn't make it into the mix. We know they're not NT but they are part of Croome and the Brown vision that the podcast is heavily based on