may-jun-2020

THE BEE BOX More than Almonds… The vast majority of commercially managed honey bee colonies in the United States spend February and a portion of March pollinating almonds in the California Central Valley. Almond pollen is very nutritious to bees, and colonies build up well on it when favorable weather conditions prevail during bloom. The weather during the 2020 almond pollination season was very favorable and colonies made significant increases in both population size and food reserves during the bloom period. While warm and dry conditions led to a good nut set this year, it also meant the almond bloom progressed quickly, and once it was finished there were few other flowers supplying significant sources of honey bee forage. Working in various almond locations from Kern county in the south to Chico near the northern end of the valley, the BIP Tech Transfer Team Field Specialists were able to cover a lot of ground and observe the plants that bees were visiting. Aside from almond flowers, bees were also seen on a few other plant varieties, from unintentionally established invasive exotic weeds, such as mustard, wild radish and filaree, to beneficial cover crops intentionally planted by almond growers and other producers in the region. Growing Wild A welcome sight in a sea of declining almond blooms is Filaree ( Erodium cicutarium ), a common occupant of orchard floors and surrounding areas where it is able to utilize irrigation water intended for almond trees. Also called redstem filaree, E. cicutarium , a member of the Geranium family, is native to Europe and Asia. Its ability to tolerate a wide variety of light, moisture, and temperature conditions has led to its widespread distribution in Mediterranean climates, particularly in the western United States. The small, pink, upright facing flowers appear in clusters on the end of hair-covered stalks. It can bloom for several months and peaks in the Central Valley during February and March. The fruits of the plant mature into a long-beaked capsule whose shape has led to one of its common names: “stork’s bill” (also regionally termed “heron’s bill”). Once the almond flowers are gone, filaree becomes an attractive option for bees as they shift their attention to orchard floor flowers if the ground cover has a significant amount of filaree. While filaree does produce some nectar, it does not do so in sufficient quantities to yield a honey crop. However, when most beekeepers have exited almonds as soon as they are released from pollination contracts, the locals that stay recognize that filaree can be an important component of spring forage. Deliberate Plantings Honey bees need an abundance and diversity of floral resources to grow and thrive throughout the season. The sole reliance on wild species to supply additional nutrition for honey bees is simply not enough. One of the pollinator friendly plants that is more commonly seen in and around orchards and agricultural fields is mustard. Its common appearance is due to both deliberate planting as a cover crop and through self-sowing. IN YOUR ORCHARD Left: This forager is collecting pollen from filaree (Erodium cicutarium) flowers on an orchard floor near Orland, California. Right: The seed containing fruits provide inspiration for the alternative common names of filaree which include storksbill or heron’s bill. Photo Credit: Dan Wyns 3 0 A L M O N D F A C T S