Where do you catch a female burmy in Pokemon diamond?

You can't catch a female Burmy in Pokemon Diamond. Burmy's gender is determined by its form, which changes based on the location it is found.

Here's how it works:

* Plant Cloak: Found in grassy areas. This form represents a female Burmy.

* Sandy Cloak: Found in desert areas. This form represents a female Burmy.

* Trash Cloak: Found in urban areas. This form represents a male Burmy.

Since Pokemon Diamond doesn't feature desert areas, you won't be able to find a Sandy Cloak Burmy (female). The only available forms are Plant Cloak (female) and Trash Cloak (male).

Therefore, you can only find a female Burmy in Pokemon Diamond in grassy areas (Plant Cloak form).