Homes Businesses Industrial Water Conservation Energy Independence Act Power Hour Pay-It-Forward Home Energy Audits Home / Rebates / Water Conservation / Xeriscape / Xeriscape Plants / Xeriscape Plants Plants listed here are found in the Riverfront Park Demonstration Garden along the Apple Capital Loop Trail in Wenatchee. Numbers refer to plant identification markers in the garden. Click on photos to enlarge and for more plant details. Back Dark Knight (Caryopteris x clandonensis) Plant type Flower Flower color Deep blue-purple Flower season Summer Plant size 4' H x 4' W Hardiness -20 degrees Light preference Full sun Winterizing instructions Trim in spring Additional comments Reliable performer with a profusion of flowering spikes Tag number in xeriscape garden 39