When Azoun IV ascended to the throne, the current Gardner Royal, one Gordroun Palonder, was reconfirmed into his position and not replaced. This despite Gordroun's advanced age and absent mindedness.
Gordroun's health steadily deteriorated. Bed-ridden and suffering from dementia, he passed away in 1352 DR. Because Gordroun had assembled a cadre of capable--and much younger--assistants, the Royal Gardens remained well kept and in good hands.
It's unknown whether Gordroun's poison garden, itself hidden in plain sight atop the Royal Stables, was removed or kept by his replacement, Relvarra Lionwinter (of the Lionwinter family who have long served in the Royal Palace as servants). The garden's existence was known to both Alaphondar and Vangerdahast, however.
Both Gordroun and Relvarra were masters of their craft, the former known for his kindness and the later for her wisdom.
