garden vs plot of land

garden and plot of land both are nouns.

Word	Noun	Adjective	Verb	Adverb
garden	Yes	Yes	Yes	No
plot of land	Yes	No	No	No

As nouns, plot of land is a hypernym of garden; that is, plot of land is a word with a broader meaning than garden:

Other hypernyms of garden include patch, plot, plot of ground.

garden (noun)	plot of land (noun)
a plot of ground where plants are cultivated	a small area of ground covered by specific vegetation
a yard or lawn adjoining a house
the flowers or vegetables or fruits or herbs that are cultivated in a garden

garden (adjective)	plot of land (adjective)
the usual or familiar type

garden (verb)	plot of land (verb)
work in the garden