The usability of basket willow rods depends almost entirely on how and when they are cut. In Poland's osier-growing districts, harvesters follow patterns shaped by climate, species growth habits, and the intended end use of the material.
Salix viminalis rods can be cut during two distinct periods: the dormant season (November through February) and the brief window in early spring before bud break. Each window yields material with different characteristics that suit different end uses.
The bulk of Polish commercial osier harvest takes place after leaf drop and before growth resumes. Dormant rods contain less moisture than summer-grown material, which simplifies drying and reduces the risk of mould during storage. The bark at this stage adheres firmly to the wood, meaning the rods can be stored without peeling for several months.
In the Nowy Tomyśl area of Wielkopolska — historically the centre of Polish wickerwork production — most smallholders schedule cutting between December and late January, avoiding periods of hard frost that can make standing rods brittle.
A second, shorter window opens once temperatures consistently exceed 5°C but before buds open. At this stage the bark loosens from the wood as sap begins to move, making it possible to peel rods by hand without steaming or boiling. Rods peeled in this state are referred to as "buff" or "white" willow, depending on the treatment applied subsequently.
Dormant-harvest rods are typically dried with bark intact ("brown willow") and later processed by boiling or steaming to loosen the bark before peeling. Spring-cut rods peel without additional treatment when processed promptly.
Rods are cut close to the stool — the woody base from which annual growth emerges — leaving a stub of no more than a centimetre. A clean cut is made with a sharp curved billhook or secateurs; ragged cuts create entry points for fungal infection that can weaken stools over time.
Cut angle matters: a slanted cut that directs rainwater away from the cut face reduces rot risk. This is particularly relevant in the flat, poorly-drained fields common in Kujawy-Pomerania, where standing water around stools after cutting is a recurring management problem.
Commercially viable basket-weaving rods typically run between 60 cm and 250 cm in length. After cutting, rods are bundled by length in groups of roughly equal diameter at the base. This simplifies use at the workbench, where consistent rod thickness within a batch affects the uniformity of the finished basket structure.
| Rod Category | Length Range | Common Use |
|---|---|---|
| Short | 60–90 cm | Small basket bases, handles |
| Medium | 90–150 cm | General basket sides, waling |
| Long | 150–220 cm | Staking, large hampers, panels |
| Extra long | 220–250 cm | Hurdle-making, large structure work |
Freshly cut rods require drying before storage. In commercial operations, bundles are stood upright in ventilated sheds, butt ends resting on clean ground or wooden rails, with space between bundles to allow air circulation. Drying to a stable moisture content — at which point rods no longer lose measurable weight — typically takes four to six weeks under normal Polish winter conditions.
Rods dried too rapidly in direct sunlight may split along the grain. Those that remain damp for extended periods develop surface mould, which stains the bark and reduces market value if the rods are to be sold as decorative-grade material.
Rods intended for use as brown willow (bark intact, dried) require no further treatment before weaving other than soaking or dampening to restore flexibility. Standard practice is to soak in water for 12–48 hours depending on rod diameter, then leave to mellow wrapped in wet sacking for a further period before working.
To produce white or buff willow, the bark must be removed. Dormant-cut rods that have been dried are processed by standing the butt ends in water for several weeks until the bark loosens ("pitting"), or more commonly by steaming the rods in purpose-built chambers for one to two hours. Once the bark has loosened, a draw knife or wooden peel is used to strip it. The resulting pale rod dries to the ivory-white finish characteristic of traditional Polish export basketwork.