Here's how you can address a female gardener in Hindi:
* बागवानी करने वाली (baagvaani karne wali): This literally translates to "one who does gardening."
* माली (maali): This is a common term for "gardener" in Hindi and is used for both men and women. You can add "महिला" (mahila) before it to specifically address a female gardener, like "महिला माली" (mahila maali).
So, instead of a specific feminine form, you use descriptive phrases or add "mahila" before the regular word.