Are Your Plants Napping When they Should?
Are Your Plants Napping When they Should? Recently we received the question, “What lighting schedule is best for my hydroponic garden?” There are a quite a few variables when growing plants hydroponically which are covered in our article, Hydroponics for Beginners. The lighting system is an essential, if not the most essential building block for quality development in a hydroponic indoor garden. While there really is no short answer, we are here to shed some light on how to properly light your indoor garden.
Don’t Faze the Phases
As far as lighting goes, hydroponics is typically broken up into the vegetative phase and flowering phase. Just like us humans or humanoids (whichever you may consider yourself), plants require a form of ‘eating’ and ‘sleeping’ to recharge. Therefore different plants require different amount of all-you-can-eat buffets and nap times, aka light exposure and uninterrupted darkness. The amount of light and darkness a plant is exposed to is called “photoperiodism.” The key is to mimic the photoperiod the plant is used to getting in its natural habitat.
Photosynthesis is fundamentally broken up into two stages, light hours (traps light) and dark hours (converts light into chemical energy). When a plant receives the suitable light levels, it is able to fill itself with the adequate chemical energy. When a plant does not receive the suitable light levels it not only gets “hangry,” it only partially fills itself with the chemical energy needed for growth. Likewise, if a plant receives more light than it is able to convert into energy, this excess amount of light (energy) goes to waste and the plant doesn’t have as much time to convert the light into energy. Just keep in mind, majority of plants being grown hydroponically love light, so the likelihood of harming a plant that with extra light is very low as long as there is a correct balance of light energy and cooling (i.e. fans, airflow).
During the vegetative phase, most plants require long 16-18 hour light cycle. It is heavily debated that a plant in the vegetative phase is even more prosperous under 24 hours of light. The concept, “more light = more growth” in theory makes sense, but plants do also require the presence of darkness to rest and recharge, just like us humans after a rough day at the office. Under a 24 hour lighting cycle, younger plants have the potential of being stressed, which can be detrimental to optimum yields.
In nature, the flowering phase usually occurs in the fall, which means short days and long nights. While longer periods of light may aid photosynthesis, they won’t encourage the “flowerset.” Instead, adding more light (lumens) is highly beneficial to the flowering phase to set you on your way to bigger flowers and yields. During the flowering phase, the chemistry in the plant changes and is quite visible. The plants stems begin to elongate, the leaves grow fewer blades, and the flower formation is noticeable. Different plants require different amounts of light and darkness exposure to flower. Short day plants require uninterrupted long nights to flower. Long day plants don’t mind the short nights or interrupted long nights of watching a midnight movie or turning on the kitchen light to devour your favorite midnight snack. Below is an example of flowering plants which require different amounts of light and darkness during this phase:
| Category | Example of Flowering Plants | Hours of Light | Hours of Darkness |
|---|---|---|---|
| Long Day Plants | Lettuce Potatoes Spinach |
18+ | <6 |
| Day Neutral Plants | Eggplants Strawberries Tomatoes |
14-18 | 6-10 |
| Short Day Plants | Chrysanthemums Poinsettias Radishes Watermelons |
12 | 12 |
Let There Be Mimicked Sunlight
Though lights may produce a high lumen output, the quality of light should mimic the sun’s spectrum. Different color wavelengths stimulate different biochemical responses within the plant. The chemical compound CO2 is best adapted when both the red and blue spectrum are present. To find out more about the presence of CO2 in hydroponic systems, check out our article, The Benefits of Using CO2 with Hydroponics. While High pressure sodium lamps tend to be rich in the red spectrum, metal halide lamps tend to be rich in the blue spectrum. In some cases, LED grow fixtures can offer both blue and red spectral blends. During vegetative states, plants require more of the blue spectrum around 475 nanometers while flowering phases require more of a red spectrum, around 650 nanometers. Combining both visible spectrums can increase formation characteristics and growth rates which could potentially lead to larger yields.
Proper distance of the light source, whether it be a grow light or grow light fixture is important to healthy photosynthesis and development. Just like I would reach for the lion cookie jar on the top shelf when I was five, plants will reach for the sought-after light source or “artificial sun.” The light source provides appropriate wave lengths your plants need to grow and prosper so why sell them short? As the light becomes more intense, it is a general rule of thumb to increase the distance between the canopy (top of the plants) and light source. Be conscious of the heat generation your light source may produce, whether it is HID or LED lighting. Overheating air temperatures can inhibit the potential yields if ventilated incorrectly.
In the light of all this, being a horticulturist or gardener is a matter of testing and find what works best for your setup. It is almost guaranteed that different lighting configurations will produce different results. If you’re feeling a little buried by hydroponics, check out our articles on The Best Plants for Beginners and 15 Best Fruits, Vegetables, and Herbs for Hydroponics. As always, for any additional questions or comments leave them in the section below. Also check back on our blog or Facebook, Twitter, LinkedIn, and Pinterest for more information. Our staff at 1000Bulbs.com is up for the challenge of answering your everyday lighting questions.
