You will then start to see the power of Saryn as the enemies just melt away as the damage ramps up. You can also periodically pop Miasma to help spread the spores and do extra damage to anyone already afflicted with one or more spores. Using a Melee with Toxic Lash activated will spread the spores even faster and do extra damage to the enemies with Spores active on their bodies already.
It will take a min or 2 to get the damage numbers up but because the enemies are high enough level they won't die right away and will allow the spore damage to ramp up easily into the 1000+/second. Just run around spamming Spores on every thing you see and watch the carnage ensue. Build Saryn for Range, Duration, and Power Strength as a rule of thumb.
Using Saryn on the Regular Star Chart is almost overkill, I recommend trying her out on ESO to see how the spores work their Mojo. 1 or 2 infected, a count of may 15 or 20. I watched videos, i read tutorials, so in theory i know how to do it.