Growing fruit trees in the Puget Sound area is supported by the region’s distinct maritime climate. Seattle’s mild temperatures and long growing season support a wide range of fruit production, despite lacking the intense heat of inland areas. Success depends on selecting varieties adapted to the winter cold and the cool, wet spring and summer conditions. Understanding the local environment is key to establishing a productive backyard orchard.
Seattle’s Unique Growing Conditions
The local climate is defined by mild, wet winters and cool, relatively dry summers. Seattle is primarily designated as USDA Hardiness Zone 9a, a recent update from 8b, which indicates that the average annual minimum winter temperature is generally above 20°F (–6.7°C). This mildness is a significant advantage for tree survival, but it introduces a different challenge: the need for adequate winter chilling.
Many temperate fruit trees require a specific number of “chill hours,” defined as hours spent below approximately 45°F (7.2°C), to properly break dormancy and set fruit. Seattle’s moderate winters typically provide the necessary chill. However, the cool, damp conditions also increase disease pressure, especially during spring bloom. Furthermore, low summer heat units mean certain fruits may struggle to achieve maximum sweetness or ripen fully before cooler weather returns.
Reliable Mainstays: Pome Fruits
Pome fruits, including apples and pears, are the most reliable choices for the Seattle climate. These trees thrive in the region’s moderate temperatures and easily meet their chill-hour requirements. Cultivating varieties known for disease resistance is a helpful strategy, particularly against apple scab, a common fungal issue in wet climates.
Recommended varieties for the area include:
- Apples: ‘Gravenstein’ (a regional favorite), ‘Liberty’ (highly resistant to apple scab), ‘Jonagold,’ and ‘Honeycrisp.’
- European Pears: ‘Orcas,’ ‘Bartlett,’ and ‘Comice’ are excellent selections.
- Asian Pears: ‘Shinseiki’ and ‘Kosui’ are well-adapted to local conditions and offer a crisp texture.
Selecting and Managing Stone Fruits
Stone fruits, such as cherries and plums, require more careful management than pome fruits in the maritime environment. The primary challenge is the high risk of fungal and bacterial diseases, exacerbated by frequent rain and humidity during the flowering period. The cool, wet spring weather creates ideal conditions for diseases like brown rot, which attacks blossoms and young fruit, and bacterial canker.
For cherries, self-fertile varieties like ‘Lapins’ and ‘Sweetheart’ are popular, though sweet cherries are vulnerable to rain-induced splitting. Tart cherries, such as ‘Montmorency,’ are more resilient and reliably productive.
European plums, including ‘Italian Prune’ and ‘Seneca,’ are less prone to issues than Japanese plums. Selecting varieties with a late bloom time helps avoid the worst early spring rains. Proper pruning to ensure good air circulation is essential for disease prevention. Apricots and peaches are the most challenging stone fruits, though ‘Puget Gold’ apricot and ‘Frost’ peach have been bred for better regional success.
Adding the Unexpected: Specialty Trees
Beyond standard orchard fruits, several specialty trees thrive in Seattle. Figs are successful if planted in a protected location that receives maximum sun exposure, such as against a south-facing wall. The ‘Desert King’ fig is notable for the Pacific Northwest, producing a reliable crop of breba figs (fruit from last year’s wood) that ripen well in the cooler summer.
Another cold-hardy option is the quince, which produces aromatic fruit perfect for cooking and preserving. Quince trees tolerate the wet climate well and are less bothered by pests than pome fruits. Hardy persimmons, such as the Asian variety ‘Izu,’ can be grown, but achieving full fruit ripening often requires a long, warm season, making them a more marginal choice in a typical Seattle summer. These specialty trees add diversity to the backyard orchard.