Here is my entry triangle garden.
It was a low place that was impossible to mow so, I sprayed with Round-up and let it die.
I got whatever was deer resistant and on BIG sale at Home Depot and used a re-located barn post for the edging. It took 3 hours.
Plants are Asters $1.50 each and a sedum sold in 6 four-inch packs for $2.50 for a total of only $14 (not bad).