I usually contact the association directly.
Most times, if you submit a plan of what & where you are planting,
it will be approved. Many neighborhoods are now allowing the home owner
to "Go Green" by planting drought tolerant & native plants, even if it's not in the HOA rules.
Gorgeous gardens add value to Real Estate & beautify the neighborhood,
so usually if you present a plan--it's a yes. They tend to get upset if you change
things without asking!