Nectar Flow and Bees
What starts and stops nectar flow in a flower? If bees collect all the nectar in a single flower, does the flower keep producing more?
Emmet County Michigan
It will depend on the species of plant and environmental conditions. For any given species, the flowers have a life span. As they age (whether it lasts on a few hours or weeks) the level of nectar production usually goes down. For many species, nectar production stops after the flower has been pollinated and the seed embryo development begins (no further need to attract a pollinator). Flowers can indeed "refill" after being visited by bees and other nectar-feeding insects. Weather plays a huge role, as the physiological activity of plants is closely tied to the ambient temperature; sugars cannot be produced if the plant is too cold. There may also be an upper limit, a high temperature could shut down nectar production as well.
So, no simple answer to a very good question.