I’m stuck on this as well, specifically with the compost item that drops from Heirloom Seed Pouches and the Risen High Wizard bone meal that drops from a mob that doesn’t always spawn at an event that only occurs randomly every 1-2 hours. I’ve sat waiting literally for hours at the Gates of Arah, only to ever see the event spawn twice and the High Wizard didn’t show either time. :/ Very frustrating and certainly not a fun game experience.
As for Heirloom Seed Pouches, I must have opened over 100 now after running Vinewrath 4 or 5 times, and I’ve gotten 4 exotics but no compost. Is this a bug or is the drop rate really that low?
For those looking for the garden trowel, I got mine off the Vet that guards the spinach garden in Gendarran Fields atop the Provernic Crypts. My guess is this item can drop from any Vet that guards permanent garden areas… I found a good list of them here: https://gw2efficiency.com/gathering/permanent-nodes