Your Plants in the Wider Environment
Verge gardens are a buffer between private properties and the stormwater system so we should avoid mulch and excess nutrients being washed down with the stormwater. That's why I prefer native plants and use a layer of groundcovers as living mulch.
We also want to avoid spreading weedy exotics by rainwater, wind or dogs.
I live on top of a hill with a creek at the bottom so I take care about the stormwater. If you live near bushland, or shops, or a pub that may also affect your choices.
For biodiversity, a range of plant types is good but with multiple verge gardens in a street, all planted to different tastes, we'll get plenty of biodiversity so it doesn't matter if you want to stick to just a few species.
Most councils have a list of recommended plants. Canberra has two lists, one is for fireprone areas. Follow them and you can't go far wrong.
Your local community nursery is a great place for advice and plants that are native to your area. These are best suited to your climate and soil and ideal for habitat.
You should also have read your Council policy carefully. If some parts of the policy seem frustrating or unreasonable to you, work within them and as you get learn more about the issues, the policies might make more sense - at least or you'll have a better idea on how to convince your Council to change them.
That still leaves you with lots of scope for creativity and your personal preferences.
This free article is part of the Understanding the Space section: bite-sized introductions to gardening in these small but wonderfully complex spaces.