What Lights Make Beanstalk Plants Grow Well?

Natural Sunlight

• Bean plants outdoor get plenty of natural light for their photosynthesis. Sunlight contains the complete spectrum. According to GrowingBeans, plant beans where they will get at least six hours of direct sunlight, although they need shade in the hottest part of the day. Climbing varieties of beans tolerate shade better than bush varieties. Beans grow indoors when placed in windows that get a lot of sunlight during the day. Filtered sunlight in winter is unlikely to provide the full amount of sunlight that bean plants need.

Artificial Light

• For indoor growing bean plants in winter, use artificial lights giving the plants all the light they need to convert nutrients into plant cell structures for healthy growth. Even with artificial light, give your plants a period of rest away from light, as they would have in natural light, according to the Gardener's Supply Company website. Incandescent lights are a good source of red light, but not of blue light. Fluorescent lights can provide blue and yellow-green light wavelengths if they are a "cool white" type bulb. "Warm white" coated bulbs emit more orange and yellow light. Full-spectrum fluorescent and high intensity discharge lights are also available, but are more expensive and may need special electrical work.

Colored Lights

• Red light assists in vegetative growth and flowering, while blue light regulates plant growth. Too much red light makes plants grow tall and spindly. Beans grow fuller and healthier with blue light. Experiments, such as the one at the Schoelles website, show that sunlight creates the best growing light for plants, because it contains all color wavelengths. Red wavelength light also produces good growth in bean plants, although plants require the full spectrum for optimum results in a variety of their internal cellular processes.