How Do Black Lights Affect Plant Growth?

Views: 19781 | Last Update: 2009-03-27
Black lights can help plants to grow and survive, but they won't have many blooms, and they will be very leggy. Find out why blue and red lights are the best artificial lights for growing plants with help from a sustainable gardener in this free video on... View Video Transcript

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Yolanda Vanveen

Video Transcript

Hi, this is Yolanda Vanveen and in this segment we're going to talk about how do black lights effect plant growth? Now plants need light and there's all types of light, and natural light has all the colors of the spectrum. That's why when you see a rainbow, the light's broken down into all the colors. But you can also grow your plants indoors using artificial light and there's all types of colors you can use as artificial light and there's a lot of theory as to which are the best colors. And basically, the blue color is the best because when the plants first grow, it's great for sprouting plants. It's just like spring light. Spring light is more in the blue spectrum. But once you get into the summer, it's more of a red-orange-yellow light and so the red light is the best when you want to have blooms or buds. So you need a combination of lights indoors to get the best plants and so fluorescent lights are the best because they have the full spectrum of colors. But when you're getting down to the black light, the problem with black light is that it's like light at night or in the middle of the winter on a really cloudy day. It's not very bright and plants will start growing in it and they will survive but they'll be very leggy. They'll reach for the sun, they'll reach for the light and there'll be no light to be had and it is almost impossible to get any blooms with a black light 'cause the plants naturally will never bloom if they're in the dark. So if you are growing plants with artificial light, remember the best lights are the blue in the spring when you're starting the sprouts and then the red lights, or the hot light, for getting blooms, and black lights are wonderful for Halloween and for entertainment purposes, but for growing plants, they really don't work that well.