Example 1: I read about how plants need water to survive. We watered our plants __ times a week and I think this ____________________________.
Example 2: I read about how sunflowers can live under fluorescent lights. We gave them light but they didn't grow. I think they didn't grow because _________________.
Example 3: I read about how plants get different colors of light from the sun and flourescent lights. I think the plants in the back of the room and in the closet got this color of light ___________ because ________________________.
Research Data:
The Right Color
Sunlight contains the complete spectrum of light including all colors of the rainbow: red through yellow to blue and violet. Plants use the full spectrum for photosynthesis, although red and blue light seem to be most critical. Red light stimulates, or helps, vegetative growth and flowering, but if a plant gets too much red light, it will become tall and spindly. Blue light regulates plant growth, which makes it ideal, or best, for growing foliage plants and short, stocky seedlings.
Some plants perform best when given more of a certain color light. An African violet will thrive under blue light, but if it doesn't receive an abundance of red light, it may never flower. If you learn what color light your plants need, you can then select the right type of bulbs to meet that need.
- Rotate your plants each week. The light from a fluorescent bulb is more intense at the center of the bulb than it is at the ends.
- Replace fluorescent tubes when the ends darken. That means the tube is old and the light output may be less than half of a new bulb.
- Clean your fluorescent bulbs each month. Dust and dirt can dramatically decrease the amount of light emitted.
- Place your hand where the light hits the foliage. If you feel any warmth, the light is too close.
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Fill your pots with a light, rich potting mix that contains peat moss and compost. Small pots are fine to use if you plan to transplant the seedlings later, but use pots that are at least a foot in diameter and a foot deep to accommodate the large root systems of indoor sunflowers.
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Choose the smallest types of sunflowers you can find for winter indoor plants. Varieties like Teddy Bear and Big Smile are good choices for potted sunflowers because they don't get more than two feet tall. Other varieties like Mammoth or American Giant can exceed 12 feet and are better suited for outdoor gardens.
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Plant two or three seeds in each pot. Sow the seeds about two inches deep and water them well.
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Place the pots in a sunny window. Natural light is the best light for sunflowers, so use the fluorescent lights to make up for lack of exposure to natural light.
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Use the brightest fluorescent lights you can find, and put them in a fixture that can hold at least two tubes. Arrange the lights so they are a few inches from the soil surface. Make sure the sunflower seeds get 12 hours of light a day, either all from the fluorescent lights or by combining natural and fluorescent light.
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Raise the lights as the seedlings grow to give them plenty of room. The lights should always be a few inches from the top of the tallest plant.
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Pick out the weaker seedlings when they are about 3 inches tall, or transplant the seedlings outdoors. For indoor sunflowers, you can transplant the seedlings you picked out to other pots if you prefer, or just throw them away.
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Keep the fluorescent lights on indoor sunflowers for their entire life cycle, making sure the flowers get at least 12 hours of light a day until the plants have bloomed out.
