Philadelphus microphyllus aka Desert Mock Orange

Philadelphus microphyllus is known as little-leaf mock orange or desert syringa. This deciduous shrub belongs to the Hydrangeaceae family. Its native range spans the west-central and southwestern United States into northern Mexico. It grows in dry, rocky sites within this range. These include sunny canyons and piñon-juniper woods. Recorded habitats lie at elevations of about 3,940–9,840 feet [1,200–3,000 metres]. It is a plant of temperate regions.

In gardens, it forms a compact shrub with upright growth. It reaches about 3.3–4.9 feet [1–1.5 metres] tall and wide. The RHS gives five to ten years to reach full size. Its dark brown bark flakes as it ages. Small, oval leaves range from mid-green to dark green. The shrub drops its leaves for winter. White flowers appear in late spring or early summer. Their strong scent adds to the shrub's value near garden paths. Its modest size suits beds where space is limited.

Grow it in full sun in a sheltered spot. The RHS lists south-, east-, and west-facing sites as suitable. Choose soil with moderate fertility that drains well but stays moist. Chalk, clay, loam, and sand can all suit it. The soil should be neutral to alkaline. Established plants can cope with drier ground. Plants For A Future also lists woodland edges and dappled shade. The RHS rates its UK hardiness as H5. Plants For A Future lists USDA zones 5–9.

This shrub suits cottage gardens, informal planting, and flower borders. The RHS includes it among plants for low-maintenance gardens. Its small leaves, white blooms, and scent provide its main garden interest. Growers can raise new plants from softwood or hardwood cuttings. Aphids may attack it, and powdery mildew can occur. Honey fungus is another possible problem, though the RHS calls it rare. Plants For A Future does not flag it as weedy.

Plants For A Future records past use of the fruit as food. It gives few details, so this offers limited guidance for eating it. The same source reports no known hazards or medicinal uses. That is not a full safety assessment for people or pets. The leaves contain saponins and make lather when crushed with water. People have used this lather to clean skin and clothes. Flowers can also serve this purpose. The cleaner removes dirt better than oil.