Which relationship structure to use?

Hello,
I have a form where each record is a different plant species (including height, width, sun/shade and other characteristics that do not change).

I have another form that is my garden inventory (which has the quantities of each plant in certain areas of my garden – for example, 5 Salvia spathacea in the bioswale and 3 Salvia spathacea along the street edge – these items do change over time as I add plants or a plant dies).

I’d like to know how I link these two. I’d like my garden inventory to link to the plant species form, so that I can just click that arrow thing and go over to the static info to check on information about how that plant ought to perform.

And, of course, I am confused. I was thinking the plant species form was the parent, but I really work from my garden inventory form because I am always updating these records – making notes about which specific plant is doing what – I keep a notes field where I make my observations about how this plant species or small group of plant of the same species are doing in that spot in my garden.

So, I may have 5 or 6 plantings of the Salvia, and on each record, I want to link back to the plant species data record. Which way should I do that?

Is the garden inventory the master? Do I use “many to many” or would “join” provide a better way of working?

Any insights would be appreciated.