Timing of asparagus production in a temperate climate

The normal harvest period for asparagus in Poland lasts from late April or early May until 20 June. An investigation was undertaken to determine if this period could be extended. Plastic covers were applied to hasten the harvest, and the soil was covered with a layer of pine bark during winter to prolong the harvest season by delaying its start. The mother stalk method and a twice-yearly harvest were also used to extend the harvest outside the traditional season. Two all-male cultivars were included in the experiment: Gynlim, an early one; and Backlim, a late one. The preliminary results of the experiment showed that it was possible to advance the start of production by 4 to 13 days and to delay it by 9 to 14 days depending on the cultivar. If the harvest time was earlier or later;the yield was similar to that obtained in a normal harvest period. However, it was significantly lower when spears were collected outside this period. The mother stalk method gave an acceptable yield with cv. Gynlim but not with cv. Backlim. The lowest yield was obtained when spears were harvested in July.