BY: Warren Tenney

Living Classroom: AMWUA Plant Pages Come To Life

Published Jun 13, 2016

In a 3.2-acre space hemmed in by traffic noise, office buildings and warehouse construction sits a living classroom. The University of Arizona's Maricopa County Cooperative Extension is a place to learn by doing - plant and nurture desert landscapes, grow vegetables and herbs, or create a rainwater harvesting system.

The Maricopa County Cooperative Extension has been at 40th Street and Broadway Road in Phoenix since the early 1970s. It was built before desert landscaping was popular in the Valley, yet its grassy landscape already included seven desert-adapted trees.

A year ago, the Extension embarked on the second landscape redesign of its demonstration garden. This time its goal is to plant every vine, succulent, shrub, groundcover and cactus - and some of the 44 trees - described in AMWUA’s plant pages. When finished, it will be a living adaptation of AMWUA’s mobile online version of the publication Landscape Plants for the Arizona Desert .  The interpretive signs are expected to link visitors to the AMWUA plant pages for more information. The redesign will include 269 species of desert-adapted plants.

Copyright: Scott Millard, Landscape Plants for the Arizona Desert

That number is not unprecedented. As part of the garden’s last redesign in 1998, most of the grass was removed and replaced with 300 species of desert-adapted plants. The goal then was the same as it is now: education. It was a place where homeowners, landscapers and designers could view an array of desert-adapted plants to help them select, install and nurture desert landscapes. The Extension’s garden is one of several free demonstration gardens the Phoenix Metropolitan area, including eight built and nurtured by AMWUA cities.

It’s been 18 years and along the way that beautiful 1998 Extension demonstration garden was left behind. It lost its status and suffered from neglect. The irrigation system grew so frail it was no longer fixable and it overwatered some plants - and an acacia tree - to death. The system left others without enough water to survive. The number of species dropped by more than half leaving only the strong and the lucky.

A year ago, the Extension began to slowly redesign, rebuild and replant this section of its living classroom. Its landscape committee is now working on the project’s first phase, which includes upgrades to the irrigation system with help from Ewing Irrigation and Landscape Supply, hardscape pathways, and a rainwater harvesting system for its trees. Planting will begin in the Fall. The extension is looking for volunteer grant writers, storytellers, and landscape professionals to help move the project along. Mostly it’s looking for people willing to use a rake or shovel and eager to learn great tips for their own landscape projects. Here is some of the work being done to revamp the demonstration garden.

  • Create wider pathways with steel edges filled with ¼-inch-minus gravel (that means ¼-inch gravel not strained to remove smaller pieces and dust) stamped with a plate compacter so the surface is hard enough for wheelchairs but still permeable to rain.
  • Extend a 2-foot gravel border along the Extension's building that contains no plants or water emitters.  This discourages cockroaches, crickets, spiders, and even termites, from living under the foundation.
  • Dig rainwater harvesting trenches along the roofline and direct rainwater runoff into large basins around the garden’s trees. The trenches are being lined with black plastic nursery pots cut in half and stabilized by rock fill. This half-pipe of plastic pots prevents the trenches from eroding and keeps the pots out of the landfill.
  • Use rough-cut compost, the chunky bits from wood chippers, to dress the garden instead of gravel. This chunky compost looks more natural, creates better and cooler soil and helps retain moisture. The plants will need less water to survive.


Building  wider, permeable garden paths

Want to get involved in rebuilding a demonstration garden, join Master Gardeners at work and learn a little along the way? Send an email to Rebecca Senior at and put “Volunteer” in the subject line.

For 46 years, Arizona Municipal Water Users Association has worked to protect our member cities’ ability to provide assured, safe and sustainable water supplies to their communities. For more water information visit .