the light that binds
there may be lighting technologies that are effective , but are so inefficient that they cut into a grower ’ s return on investment .”
There are many horticultural lighting technologies available that can promote plant growth , but the key to finding the best lighting system is to look at both the effectiveness and efficiency . Put another way , there may be lighting technologies that are effective , but are so inefficient that they cut into a grower ’ s return on investment . On the other hand , there are lighting systems that are inexpensive , both to purchase and to operate , but lack the ability to promote healthy plant growth .
The Cloning / Seedling Stage
The cloning / seedling stage is one of the most important stages for an indoor horticulturist to master . If the grower wishes to have a perpetual garden , a high cloning success rate is imperative for success . Horticulturists who grow from seed will also need to have a high success rate to have a productive outcome . Some seed varieties are very expensive , so low germination rates are simply not an option . Along with keeping the atmospheric conditions consistent ( crucial for success in the cloning / seedling stage ), choosing the proper horticultural lighting system is imperative . The proper lighting system in this stage will not only help increase success rates , but will also increase the rate at which the plants can be rotated into the subsequent stages .
High Intensity Discharge
High intensity discharge ( HID ) lighting systems ( including metal halide and high pressure sodium ) were once the industry standard for all stages of growth , including the cloning / seedling stage . Although HID lights will work during this stage of growth , they have a few disadvantages that make them less than perfect . During the cloning / seedling stage , plants do not need the light to be as intense as in later stages of growth . A lighting system that is too intense can cause damage or retard growth . HIDs emit light from a single point on the bulb , which means plants closer to the bulb will receive much more light than plants farther away . In other words , HIDs are terrible at creating uniform light footprints for small plants . Inconsistency during early
stages of growth can cause a whole slew of problems later down the line . Another disadvantage of HID lighting for the cloning / seedling stage is the immense amount of heat emitted . If not addressed , this heat may be too much for sensitive seedlings or tender clones . Although it can get the job done , HID lighting is probably not the best choice for the cloning / seedling stage . HID ’ s intensity and requirements for additional ventilation equate to inconsistency and inefficiency .
Fluorescents and Light Emitting Diodes
Most professional indoor gardeners prefer fluorescents or light emitting diodes ( LEDs ) for the cloning / seedling stage of growth . Both fluorescents and LEDs offer a lower heat signature than HID lighting and generally are available in lower wattages . This is extremely important because the amount of light energy required by the plants is calculated by the size of the garden space . During the cloning / seedling stage , the plants are much smaller , which means they will not need as much light energy . This , combined with the fact that they simply do not need as much light during this stage , means a low wattage system is more suitable . A common rule of thumb for light energy in an indoor garden is 40W per square foot .
116 Maximum Yield USA | February 2017