Portland's International Rose Test Garden: History, Care, and World-Class Roses

Portland, Oregon's "City of Roses" reputation centers on the International Rose Test Garden—America's oldest continuously operating public rose test garden, founded in 1917.

Historical Significance

• Originated as safe haven for European rose varieties during WWI.
• Now 10,000+ plants, 650+ varieties across 4.5 acres.
• One of 24 All-America Rose Selections (AARS) test sites.
• One of 6 American Rose Society miniature rose test gardens.

Garden Sections

• Royal Rosarian Garden: Honors Portland's civic ambassadors.
• Shakespeare Garden: Roses named for Bard's characters.
• Miniature Rose Garden: Dedicated test beds.
• Gold Medal Garden: AARS winners only.

Professional Care Regimen

Task	Timing	Details
Irrigation	Early morning	Automatic underground; moist roots, dry foliage by noon
Fertilization	Apr, Jun, Aug	15-10-10 + micros (Portland Rose Society formula)
Soil Amendment	Annually	Garden compost primary
Pest Spray	10–14 day intervals	As needed; IPM approach
Topping	November	Cut to ~3 ft
Pruning	February	12–18″ height per variety vigor

Volunteer & Community Support

Maintained by 1 full-time gardener + hundreds of volunteers (Master Gardeners, Rose Society, Royal Rosarians, Festival Association). Public ownership ensures accessibility and education.

Visiting Tips

• Peak bloom: June–October.
• Free admission; dawn to dusk.
• Washington Park location—combine with Japanese Garden, Zoo, Hoyt Arboretum.
• Guided tours available summer weekends.

This living laboratory preserves rose heritage while testing tomorrow's classics—all in a setting of stunning beauty.