What a very interesting question! It is true that different light colors in the spectrum provide different benefits to the plants they shine on. Some make them grow faster, others aid the photosynthesis process, and some aid in the regenerative process.
One of the awesome perks of growing a hydroponic garden instead of a more traditional garden is having control over what kind of light source is used to aid the growth of the soil free planting experiment. If you are planning to only use the light of the sun, then this light spectrum experimentation will be harder to implement. If, however, you are planning to add an LED grow light to your indoor hydroponics system of gardening, then you will be able to find a system that will shine different LED lights throughout the light spectrum should you so desire.
Sunflowers are a great crop to try in a hydroponics gardening system because they are a hardy plant, hard to kill, very useful, pretty, and somewhat sensitive to the different colors in the light spectrum. If you are thinking of looking at the effects of different colored LED lights on a crop, then sunflowers would be a great seed to try this with.
The answer to this isn’t quite as straightforward as you might think. But really, is anything every as straight forward as you want it to be these days? It sure doesn’t feel like it. Anyway, different colors will bring out different benefits to the sunflowers in your hydroponics gardening system, so we think the best answer to the question of what color of light will a sunflower garden grow best in, is a variety of colored lights at different times. We think you should shine different colors for different intervals of time to make sure you are getting the different benefits for your sunflowers.
White is the color of light most people use in their hydroponic sunflower gardens because white light is actually utilizing every color in the spectrum. This is a simple way to get all the benefits you want for your plant at once. If you don’t feel light trading out colored lights at different times, then white may be the way to go. It is a low-maintenance option. If, however, you want to switch things out and make things more exciting, then read on to see what the other colored lights can do for your indoor hydroponics sunflower garden.
Blue lights are a great way to get the leaves and petals of your plants to grow well. The leaves and petals love blue light as it stimulates growth and reproduction at a fast rate. If you want big head on your sunflowers, then a couple hours of blue light exposure every day can really help with that. Blue lights can be found in LED or halogen form. They are easy to find, fairly inexpensive, and can speed along the growth rate of your plants in an awesome way. However, you don’t want to rely solely on blue lights because if the leaves start to outgrow the capacity of the roots (which blue lights won’t help much with) then you will have a problem, and your lovely indoor sunflowers will stop flourishing in the way you want.
Red Lights are another good color to put on your plants for an hour or so a day. Red lights are hot. If you live in a cold area or have your hydroponics system in an area that doesn’t hold heat as well as other places, then red lights is a great way to up the temperatures and stimulate the growth of the plant and the strength of the roots. Using red lights on their own can be a risk as some plants, sunflowers included, don’t like it to be hot all the time. You will have to switch the red lights out with something else, but adding in a splash of red every now and again can really perk up your soilless crop of sun flowers in a huge way. Plants like heat, and red light delivers that heat in an easy and mess-free way.
If you don’t have the time to monitor the red light effect on your plants, then another way to give them that sweaty goodness is to use orange lights instead. The orange lights are not as good for the plant as the red, but they aren’t as dangerous in overexposure either. This means that your plants can still get warmed up through the use of a reddish tinted light without you having to be there to switch out the light color as soon as if you had used red.
Another way to control how long the blue and red lights are used on the plants to make sure over exposure dangers are not posed to the sunflowers is to get a timer. These are easy to find and set up, and work especially well on LED sets. Some LED grow light systems actually come with these timers built in. If you are trying to choose between more than one LED grow light system and you know one of them has a timer, go with the timer every time. Trust us, you won’t regret it. Having the timer on means you can work your garden’s schedule around your own and not the other way around. We know that hydroponic gardening is fun and a worth while activity, but nobody wants to be a slave to a garden watering and lighting schedule.
So, there you have it. The best colored lights for sunflowers to grow under is a mixture of white, red, and blue lights. Very patriotic, no? If red is not something you want to deal with the risks of, then either cut it out completely, or use orange lights instead. Having this fun system of switching out colored lights will make your plants happy and will stimulate the growth of each part of the plant in an even way.
– See more at: http://wickedhowtos.com/hydroponicsystems/category/grow-lights#sthash.GLq3H47C.dpuf
Ever since I hooked an ignition coil up to a car battery and zapped myself I've been interested in 'how-to' do all sorts of things--I put some of them here.