Climatic Bait & Switch

This composition of Mexican feather grass (Nasella tenuisima) and purple pineapple lily (Eucomis) still looks good at the end of the dry season in the garden of Lauren Hall-Behrens, Portland, Or.

Yes, it rains a lot in the Pacific Northwest… except when it doesn’t. People outside the region scoff at the notion of a PNW dry garden. Trust me, in the midst of a stretch of sodden weeks (say, anytime between October and April) sometimes it’s hard to believe it ourselves.

Earlier this month, a scant two-hundredths of an inch of rain fell at Sea Tac airport; enough to break a streak of dry days and end the second longest dry period since 1951–49 straight days without precipitation. That measly measure might have been enough to thwart a new record, but it did little to quench our thirsty gardens. Since then, not a drop has fallen.

Most years, seasonal drought reliably show ups–whether temperatures rise or not–between July and September. PNW gardens, acclimated to constant moisture for most of the year, must adapt to a punishing dry spell, generally followed by the heaviest rains which typically arrive in November.  It’s enough to send both moisture-loving and drought-resistant plants to an early grave.

The good news is our somewhat tardy PNW summer has been glorious with warmth and heat (finally) producing a respectable crop of ripe tomatoes. The bad news is trees and shrubs are showing the stress of an extended dry period.

In spite of the challenge to keep the garden going under such dry conditions, these golden days are some of my favorite of the entire year. Autumn officially arrives this Saturday. The delicate balance of warm days and cool nights will soon tip over into nearly constant dark and damp.