Bigbryantn
Active Member
This article came out in an agricultural mag and I think might help some of those contemplating which light cycle to run for autos.
When growing plants indoors, it becomes your job to provide all of the things Mother Nature would in the plant’s natural habitat. Light is one of the most important things you must provide and like other needs, requirements vary from one plant species to another. Many plants do well under 24-hour artificial lighting, but there are a handful that will refuse to bloom and perform their best under these circumstances. Others will thrive and bloom faster than usual when continuously exposed to light.
The Dark Side of Photosynthesis
Photosynthesis involves two biochemical processes, known as light reaction and dark reaction. During light reaction, the plant absorbs light and turns it into energy. This energy is in an unstable form, however, and cannot be stored for later use. To solve this problem, the plant's dark reaction converts these energy compounds into carbohydrates, which can be stored and accessed later. As the name implies, light reactions do need sunlight or artificial light to occur. Dark reactions, however, can happen at any time and often occur while the plant is exposed to light. Because dark reactions do not require the absence of light, plants will remain healthy when exposed to light 24 hours a day. There are some plants, however, that will survive but not thrive without darkness.
Plants That Crave Darkness
Some plants are photosensitive and need a certain amount of darkness in order to bloom. Winter-blooming plants, such as poinsettias (Euphorbia pulcherima), bloom in response to the season’s shorter days. When grown outdoors in U.S. Department of Agriculture plant hardiness zones 9 through 11, poinsettias automatically receive less light as days grow shorter. Indoors, these plants need you to regulate the light for them. Kalanchoe (Kalanchoe blossfeldiana) and Christmas cactus (Schlumbergera truncata), both perennial in USDA zones 10 through 12, are also photosensitive and won’t bloom when continuously exposed to light. Spider plants (Chlorophytum spp.), perennial in USDA zones 9 through 11, do best with 12 hours of light a day rather than 24.
Loving the Light
While some plants need a certain amount of darkness to bloom, others crave light. Exposure to 24-hour light helps some plants like orchids (Orchidaceae spp.) and cacti (Cactaceae spp.) bloom more quickly than they normally would if grown outdoors. Orchid varieties, depending on species, grow outdoors in USDA zones 1 through 11 while cacti, also depending on species, are perennial in USDA zones 5 through 13. Many houseplants and bedding plants also do well in 24-hour lighting, including coleus (Coleus hybridus), Swiss cheese plant (Monstera deliciosa) and dieffenbachia (Dieffenbachia spp.). The Swiss cheese plant and dieffenbachia both are perennials in USDA zones 10 through 12, while coleus is grown indoors or as an annual.
A Word on Intensity
When experimenting with or altering the amount of light your indoor plants receive, remember that the intensity of the light can be as important as the amount. Some plants require bright, intense light while others require low or indirect light. A plant that looks dull and has smaller leaves than it should is not getting enough light. Try increasing the intensity of the light the plant receives or start providing light 24 hours a day. Plants that receive too much light turn yellow in color and may eventually be covered in patches of dead, burnt tissue. Help these plants by moving the light source further away, reducing the intensity of the light they receive, or by providing longer periods of darkness.
When growing plants indoors, it becomes your job to provide all of the things Mother Nature would in the plant’s natural habitat. Light is one of the most important things you must provide and like other needs, requirements vary from one plant species to another. Many plants do well under 24-hour artificial lighting, but there are a handful that will refuse to bloom and perform their best under these circumstances. Others will thrive and bloom faster than usual when continuously exposed to light.
The Dark Side of Photosynthesis
Photosynthesis involves two biochemical processes, known as light reaction and dark reaction. During light reaction, the plant absorbs light and turns it into energy. This energy is in an unstable form, however, and cannot be stored for later use. To solve this problem, the plant's dark reaction converts these energy compounds into carbohydrates, which can be stored and accessed later. As the name implies, light reactions do need sunlight or artificial light to occur. Dark reactions, however, can happen at any time and often occur while the plant is exposed to light. Because dark reactions do not require the absence of light, plants will remain healthy when exposed to light 24 hours a day. There are some plants, however, that will survive but not thrive without darkness.
Plants That Crave Darkness
Some plants are photosensitive and need a certain amount of darkness in order to bloom. Winter-blooming plants, such as poinsettias (Euphorbia pulcherima), bloom in response to the season’s shorter days. When grown outdoors in U.S. Department of Agriculture plant hardiness zones 9 through 11, poinsettias automatically receive less light as days grow shorter. Indoors, these plants need you to regulate the light for them. Kalanchoe (Kalanchoe blossfeldiana) and Christmas cactus (Schlumbergera truncata), both perennial in USDA zones 10 through 12, are also photosensitive and won’t bloom when continuously exposed to light. Spider plants (Chlorophytum spp.), perennial in USDA zones 9 through 11, do best with 12 hours of light a day rather than 24.
Loving the Light
While some plants need a certain amount of darkness to bloom, others crave light. Exposure to 24-hour light helps some plants like orchids (Orchidaceae spp.) and cacti (Cactaceae spp.) bloom more quickly than they normally would if grown outdoors. Orchid varieties, depending on species, grow outdoors in USDA zones 1 through 11 while cacti, also depending on species, are perennial in USDA zones 5 through 13. Many houseplants and bedding plants also do well in 24-hour lighting, including coleus (Coleus hybridus), Swiss cheese plant (Monstera deliciosa) and dieffenbachia (Dieffenbachia spp.). The Swiss cheese plant and dieffenbachia both are perennials in USDA zones 10 through 12, while coleus is grown indoors or as an annual.
A Word on Intensity
When experimenting with or altering the amount of light your indoor plants receive, remember that the intensity of the light can be as important as the amount. Some plants require bright, intense light while others require low or indirect light. A plant that looks dull and has smaller leaves than it should is not getting enough light. Try increasing the intensity of the light the plant receives or start providing light 24 hours a day. Plants that receive too much light turn yellow in color and may eventually be covered in patches of dead, burnt tissue. Help these plants by moving the light source further away, reducing the intensity of the light they receive, or by providing longer periods of darkness.
