Hi Sarah! This is a great question about Chamomile. There are many similarities between the two chamomile species, and often they are used interchangeably. They do have different amounts of certain phytochemical and aromatic compounds which you may notice if working with both species. Generally, German Chamomile is the preferred type to use for infusions based on its flavour and medicinal potency. In my experience, German chamomile is more enjoyable as an infusion but Roman can be very nice too! It is also interesting to note that German Chamomile is an annual plant, whereas Roman Chamomile is a perennial, which you may have noticed in your garden. I’d say go ahead and make use of what you have as an infusion or, in any way you would use German Chamomile. If you can access some German flowers, it may be interesting to do enjoy both as infusions side-by-side to see if you can notice any differences.
Here’s an article that outlines some of the differences in bioactive constituents of the two species if you’d like to dig deeper.