Manual Growing lights
it takes up to 60-90 minutes for the last foraging bumblebee to return to the
hive. Under low light conditions, this time increases up to 120 minutes. [...] equipped with a blue hive door (in the visible spectrum for bumblebees) and
has a special, flower shaped, UV pattern around the entrance of the hive to help the [...] lights come on and start to close 10 to 12 hours later.
Switching on the growing lights before midnight, causes the flowers to close as early as 10:00 in