Hortus is garden; horti is gardens.
"Garden" in not gender specific in Englisg; it does not have a masculine or feminine form. While romance languages such as Spanish, French and Latin have a great number of gender specific terms, English has very few, and even these are going by the wayside from disuse, such as "actor" and "actress".
The possessive form of the plural noun pollinators is pollinators'.The plural possessive name for the garden of pollinators is: Pollinators' Garden
The noun Betty Garden is singular, not plural or possessive. The plural form is Betty Gardens; the possessive form is Betty Garden's. Betty Garden is a proper noun because it is the name of a person or a place; proper nouns are always capitalized.
Forum---Plural Form Forums,Foreign Plural Form Forumina
Cubicula.
Linguae.
The Latin masculine noun draco (a snake) has the nominative plural form dracones
Gladioli (actual Latin plural) or gladioluses (Anglicized).
The plural of vertebra is vertebrae.
The possessive form of gardeners is gardeners'.
Actually, the plural form radiuses is accepted as correct and has found it's way into dictionaries (see the link below). The word radius and the plural radii are derived from the Latin word radius, a word for the spoke of a wheel. The plural form is a standard form for a plural in Latin.
culinae