Sunlight is a key
component for plant growth. However, natural
sunlight is not the best light for plants. In fact, direct light
may even damage plants. The same harsh rays that cause sunburns in people can
also singe plant’s foliage. Studies show that diffused light is the best light
for growing. Growth rates increase 20
to 30 percent under diffused light when compared to plants grown
under more direct light. Diffused light reaches your plants from all angles,
allowing light to contact leaves that would not normally get much light. Plants
are consequently able to photosynthesize more and produce more food to promote
healthy, robust growth.
Diffused light also produces fewer
shade spots in your greenhouse, which means that plants don’t
have to strain to reach towards available light. As a result, the plants develop
bushy, compact growth opposed to unattractive, leggy growth. Some greenhouse
coverings may diffuse light to some extent, but still transmit too much direct
light. This additional light may ultimately cause more harm than good
because too much light causes plants to waste energy through transpiration.
Excessive heat, also a consequence of more direct light, can stress plants and
reduce photosynthesis rates.
If
your greenhouse paneling does not naturally diffuse available sunlight you run
the risk of harming your plants. I
lieu of changing your glazing or moving the position and site of your
greenhouse, you can use a shade cloth. Draped
over the outside of your nursery, a shade cloth blocks or diffuses the light
that enters your growing space. The
percentage of light blocked is determined by the weave and material of the
blanket. Most attach with grommets or to the frame of your nursery
structure. Be sure to use and
position the shade cloth to provide the most protection possible for you plants;
in the summer when the sun is highest in the sky, between 10 a.m. and 5 p.m. and
over any greenhouse that has excessive western exposure.