Light is critical to the health of plants. The rate of growth and length of time a plant remains active is dependent on the amount of light it receives. Photosynthesis, the plant’s most fundamental metabolic activity, uses light energy. When determining the effect of light on plant growth there are three areas to consider: intensity, duration and quality.
Light Intensity
Light intensity effects plant food production, stem length, leaf color, and blooming. Plants cultivated in low light are often spindly with pale green leaves. A identical plant growing in direct sunlight has shorter, better branches and bigger, dark green leaves.
Light exposure
Plants are categorised according to their light requirements, which include high, medium, and low light requirements. The intensity of light received by an indoor plant is proportional to its proximity to the light source. When one moves away from the light source, the intensity of the light falls fast. The intensity of natural sunlight received by plants is affected by the orientation of windows in a house or business. The light is particularly bright in southern exposures. Eastern and western exposures get around 60% of the intensity of southern exposures, whereas northern exposures receive 20% of a southern exposure’s intensity. The southern exposure is the hottest, the eastern and western exposures are cooler, and the northern exposure is the coldest. Additional elements that influence light intensity include curtains, trees outside the window, weather, season of the year, shading from nearby buildings, and window cleaning. Within a house or workplace, reflective, bright-colored surfaces tend to enhance light intensity, whereas dark surfaces diminish light intensity.
Directional Exposure:
Day and Night:
The length of the day or the duration of light received by plants is also important. Poinsettias, kalanchoes, and Christmas cactus only bloom when the days are 11 hours or shorter (short-day plants). Some plants only flower when days are longer than 11 hours (long-day plants), while others are not sensitive to day length at all (day-neutral plants).
Day Length:
Increased light exposure time (duration) may be utilized to compensate for low light intensity, as long as the plant’s blooming cycle is not affected by day length. Longer light duration enables the plant to produce enough food to live and thrive. Plants, on the other hand, need some darkness to grow correctly and should be exposed to light for no more than 16 hours a day. Much light is just as bad as little light. When a plant receives too much direct sunlight, the leaves get pale, occasionally burn, brown, and die. Protect plants from too direct sunlight throughout the summer months.
Supplemental Light:
Incandescent or fluorescent lights may be used to provide additional illumination. Incandescent lights generate a lot of heat and use a lot of power. If artificial light is the sole source of light for growing plants, the light quality or wavelength must be taken into account. Plants need predominantly blue and red light for photosynthesis, but infrared light is also required for blooming. Incandescent lights emit mostly red and infrared light, with relatively little blue light. The quantity of phosphorus used by the producer determines the price of fluorescent lights. Cool-white lights emit predominantly blue light and emit little red light; they are cool enough to be placed near to plants. Foliage plants thrive under cool-white fluorescent lighting, while flowering plants need more infrared light. Incandescent lights or horticultural fluorescent lights may do this.
Temperature
Most plants can withstand regular temperature variations. In general, foliage plants thrive in temperatures ranging from 70 to 80 degrees Fahrenheit during the day and 60 to 68 degrees Fahrenheit at night. Most blooming plants enjoy the same daily temperature range, but thrive best when nighttime temperatures range between 55 and 60 degrees Fahrenheit. Lower evening temperatures assist the plant in three ways: recovering from moisture loss, intensifying blossom color, and extending floral life. Excessively low or high temperatures may cause: plant stress, inhibit growth, or promote a spindly appearance and foliage damage or drop. Cold nighttime temperatures are really better for plant development than hot days. As a general guideline, maintain nighttime temperatures 10 to 15 degrees cooler than daytime levels.
Misting:
The proportion of moisture in the atmosphere is represented as humidity. This is vital for plants because it allows them to control moisture loss and temperature. There are several methods for increasing relative humidity around plants. A humidifier may be connected to the house or office’s heating or ventilation system. Gravel trays with a consistent moisture level may also be put underneath plants or containers. When the liquid surrounding the pebbles evaporates, the relative humidity around the plants rises.
Humidity
Another way to increase humidity is to put plants together. Misting plant leaves is not normally suggested due to the increased risk of disease transmission. If a mist is used, it should be applied early in the day so that leaves will dry before the onset of cooler nighttime temperatures.
See Specific Light and Temperature Requirements for further information. Selected Foliage and Flowering Plants
