ROTATING YOUR HOUSEPLANTS

BUT WHY? Aesthetics…yes but there is a scientific reason as well… 

Phototropism

Diagram of phototropism

Plants have evolved a way to adapt to the variable light conditions in which they are growing. It is called a phototropic response - the bending of a plants stems and leaves towards the light source – specifically a directional blue light source.This movement is also called orthotropic – in other words it gets directed towards the source. It allows a plant a mechanism to alter their growth and development to changes in light intensity, quality and direction.The response is not only a movement toward the light but also against the force of gravity. It happens because more auxin (plant hormone) is distributed to the side away from the light than to the side toward it. Auxin controls cell elongation and growth causing the shaded side to elongate more strongly. This curves the leaves and stems.Sometimes the auxin is actually destroyed by the light – so the darker side which has more auxin elongates. 

Function of Auxin

 The plant through its actions is trying align its leaves and stems so they are perpendicular to the light source. This allows for maximum angle penetration of the photons in the light to reach the cells that make sugar. Eventually the entire foliage canopy is facing the light ! 

The problem

 Of course, this light response makes the plant look lopsided! But more importantly – it does not allow for all the leaves to receive the proper amount to light. Those on the side that faces the light gets more than those behind. 

a lopsided plant  !

 It is not very common but sometimes the amount of sugar produced in those farther away leaves is so little – the plant simply drops them. 

The solution

 That is why we rotate the plants! So that they keep their shape and all leaves are able to get the full perpendicular light they want - as they get rotated.How often to rotate is a matter of contention - I recommend a weekly ¼ turn. Some literature suggests once a month. 

All houseplants will benefit from rotating - how often is up to you !

Call us if you need help ! 

PLANT SPECIALISTSGREENING NEW YORK FOR OVER 53 YEARS !

   Article written by our Staff Horticulturist, Peter B Morris, BSc, MSc, MBAAll photographs used with permission @SHUTTERSTOCK