September is Planting For Monarchs Month,  and Phoenix's Office of Environmental Programs asks families and gardeners to consider the well-being of the butterflies as they plant for the fall.

The western population of the monarch butterfly has declined by more than 90% over the last 20 years, city officials said in a release.

Researchers believe one of the primary causes is habitat loss, and that's why the Valley is so important.

"Butterflies migrate through the Phoenix each year from about September to May. Milkweed and native nectar plants can help give them a food source and a place to lay eggs while they're here," the release stated.

“We want to make sure that we are helping to provide the migratory resources that this species needs to be able to complete its life cycle and its migration cycle," said Environmental Programs coordinator Tricia Balluff.

How to help:

• Plant native milkweed such as desert (rush) milkweed or Arizona Milkweed.
• Plant native nectar plants such as pink fairyduster, desert lavender, blackfoot daisy and desert marigold.
• Protect monarch gardens by avoiding the use of pesticides as much as possible
• Trim monarch plants when the flowers are not blooming.

“It can be any size of effort, from a potted plant on a balcony to a whole yard full of native nectar resources," Balluff said.