Blackberries are a defining feature of the Washington summer landscape, with their thorny canes and dark, sweet fruit. The yearly harvest is not limited to a single short window, but rather a long, varied season that changes depending on the specific type of berry. Understanding the timing of these different varieties allows enthusiasts to extend their foraging and picking from early summer well into the autumn months.
Defining the Washington Blackberry Seasons
The blackberry season most commonly recognized by Washington residents is largely dictated by the invasive Himalayan blackberry (Rubus armeniacus). This non-native species, known for its thick, thorny thickets and large, juicy fruit, dictates the main foraging window across the state. The season generally begins in mid-July as the first berries fully ripen on the heat-exposed canes.
The peak for the Himalayan variety occurs throughout August, when warm, sunny days maximize the sugar content and the volume of ripe fruit. The harvest often continues into early September, gradually tapering off as the weather cools. Picking during this peak yields the largest and sweetest berries, though foragers must contend with the plant’s robust thorns.
Timing Variations: Cultivated and Native Berries
While the Himalayan variety dominates the landscape, Washington’s cultivated and native berries offer harvest windows that bookend the main season. Trailing blackberries (Rubus ursinus), the only true native species, are generally the first to ripen, sometimes appearing as early as late May or June. These native dewberries grow low to the ground and produce smaller, delicate fruit. Although highly prized for its flavor, this native variety is far less common than the invasive types.
Cultivated varieties, such as the Marionberry or Triple Crown, are often available earlier than their wild counterparts, frequently starting in late June or early July. Marionberries, a popular cultivar, typically have a controlled harvest season lasting about four weeks, usually spanning from mid-July through mid-August. These farmed berries are selectively bred for superior flavor and size. U-Pick operations can extend availability by growing multiple varieties that ripen sequentially until the first frost.
Where to Pick: Rules for U-Pick and Wild Harvesting
For those seeking a guaranteed harvest of high-quality, often thornless berries, visiting a U-Pick farm is the most reliable option. These operations cultivate specific hybrid varieties like ‘Triple Crown’ and ‘Natchez’ that offer a consistent picking experience. It is advisable to call ahead to U-Pick locations, as harvest schedules are short and can change quickly based on weather and customer volume.
Wild harvesting, particularly of the abundant Himalayan blackberry, is permitted on many public lands, but requires knowledge of specific regulations. On Washington State Parks lands, non-commercial harvest for personal consumption is allowed up to a limit of two gallons per person per day. Harvesting is prohibited in Natural Area Preserves, and specific areas may be closed or have different posted limits.
Foraging on lands managed by the Washington Department of Natural Resources (DNR), such as state forests, permits up to three gallons of a single species of berry per person annually for personal use. Picking in areas like roadside ditches should be approached with caution, as berries near high-traffic areas or agricultural fields may have been exposed to vehicle exhaust or chemical sprays. Regardless of the location, wearing thick gloves is recommended to protect against the plant’s sharp thorns.