Design

All plants in the garden need to tolerate full sun.

Location

Because our primary goal was to drain the giant puddle at the east end of the parking lot, the garden needed to be next to the parking.  But during winter, plows would dump huge piles of snow where we hoped to build the garden.  When we consulted on-site with the MMSD's head of buildings and grounds, he agreed to avoid the garden and pile snow more to the west.

There's no slope downhill away from the garden, providing a way to drain it.  That, plus the heavy clay soil, means that water from a storm may linger for days.  So students could access the garden even when flooded, stepping stones were provided down the center where water lingered.

Many species of plants cannot survive for long in
standing water, so Carlene Bechen and Molly Wagner were looking for a way to drain the garden.  There's an imperceptible slope to the west, so an additional basin built there, with a channel connecting to the main garden.  Here they planted water-loving sedges. This mostly worked.

Likewise, plants more tolerant of standing water were planted in lower parts of the main garden.  Usually, plants of the same species were grouped together, since this is how nature does it.  And, groups of plants make for a more attractive garden because areas with contrasting color and texture give the garden a visual structure.  If you just mix together all the different species, the garden looks chaotic.

Entrance to the garden

Due to very large amounts of runoff, we worried about erosion where water leaves the pavement and enters the garden.  First we used straw mulch (photo) to protect soil at the entrance.  The first storm after construction confirmed our fears--so added an erosion control mat. 

Borders

Borders are attractive and provide a low-key message to "stay out."  They keep grass from creeping in or garden plants from escaping.  The students made borders of multicolored bricks.