For the container/backyard grower you want your roots to look like this when you repot your plant.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/hostafarian/14815779278/in/album-72157659727243221/" title="Healthy roots"><img src="https://farm4.staticflickr.com/3857/14815779278_93bdc95219.jpg" width="500" height="375" alt="Healthy roots"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>