Typically, a nectar flow happens in the spring when there is ample rainfall patterns and there is an abundance of nectar coming into the hive on a daily basis. Many areas often see a second, but lesser nectar flow during autumn. The extent of the flow is normally based on weather conditions. Even though we may see flowers all around, without moisture in the ground the blooms are not able to produce much nectar.
When the seasonal rains come and there are active blooms around, the scent of nectar and pollen is in the air. The scout bees will locate the sources and report back to the hive with samples and directions. The scouts preform the "Waggle Dance" to communicate the locations where they found the goods and share samples and with their sisters and the hard work of harvesting the lifeblood of the hive begins.
Once the message gets spread across the field bee workforce, the entrance of the hive becomes extra busy and bees coming in with pollen baskets full can bee seen in abundance. The variety of colors of pollen coming into the hive shows the diversity of forage available. The different colors come from different floral sources, each having their own nutritional values and properties, offering higher rates in the quality of the bee's diet.
The frames in the hive that already have honeycomb will begin to fill up fast and any blank frames of foundation will begin to show signs of fresh pretty white pure wax. This is known as Drawn Comb, and happens as the bees "draw out" wax, or build it up onto the foundation's preformed honeycomb cells. The influx of resources triggers the wax glands and they start to produce fresh was in the younger population. The younger female worker bees of this age group, typically around 12 to 18 days old, are often referred to "wax builders" and are responsible for producing and forming the beeswax into the cells that build up the honeycomb.
They will continue to build as long as the resources are abundant. As the seasons change, or moisture levels drop, the resources become limited and even non-existent. This is known as a Nectar and/or Pollen Death, basically the opposite of the Nectar Flow.