Well firstly let�s have a look at light & how it works. The light from the sun or from your light bulb, that we see, is known as white light & is part of a broad spectrum of electromagnetic radiation that also includes radio waves, microwaves, infrared waves (heat), ultraviolet waves, X-ray, and gamma rays to mention but a few. This white light is divided into different wavelengths & each wave length is represented to us visually as a colour. Now we see things as a colour & this is because that object contains things called pigments. These pigments absorb all light except one particular wavelength of light or colour. That wavelength (colour) is reflected off the object & absorbed by the our eyes, hence we see the object as being the reflected colour. Our orchids, like all plants need a certain amount of light to be able to carry out an essential process called Photosynthesis. In simpler terms, this is using the suns energy which is absorbed into the chlorophyll cells in the green stem & leaves, to convert water (with it�s nutrients) & carbon dioxide into sugars that the plant can then uses as energy for the growth of leaves, roots and flowers. During this process your plant will give off oxygen, which is lucky really, because that�s what we need to breathe. Who said that your plants don�t care about you? Now orchids contain two main pigments in their leaves these are Chlorophyll, which is good at capturing all the useful light energy, & this reflects only the green light, which is no good to it, so this is why we see the leaves as green. The other pigment is Carotenoid, which is no good at capturing useful light, & this reflects a yellowish colour. If your plant is not getting enough light, it produces more & more Chlorophyll to capture all the available light energy there is, the more Chlorophyll it produces, the darker green the leaves are. If your plant is getting too much light, it has more energy than it can utilise, so it doesn�t need to keep so many Chlorophyll molecules, therefore the Carotenoids become more prominent & the plant takes on a yellowish appearance. From this you can get an idea whether your plant needs more or less light. Most plants leaves should be a nice uniform green, maybe just paling a little. Now the above is only a rule of thumb indication, & indeed some genera may actually prefer either darker or lighter foliage. If you have any doubts or questions about just how much light your orchid needs, just ask any of our more knowledgeable members at the club, & if your not too sure who, ask anyone, they soon put you in touch with someone that can help. That�s why we�re there� |
| How does light affect my plants? |
| Back to the Home page.... |
| Email me ....Macara@xtra.co.nz |
 |