September 25, 2019
Cultivation Considerations for Non-Flowering and Flowering Crops
Not all growers are the same – and they’re certainly not all growing the same crops. But indoor growers – whether they’re cultivating leafy greens, microgreens, perennials or cannabis – do have one thing in common: they can all benefit from using LEDs in an indoor grow space or as supplemental lighting in a greenhouse. Here, we explore how LEDs can support both non-flowering and flowering crops, and important lighting considerations for growers of all types.
Red Light, Blue Light or a Little Bit of Both?
The first aspect to consider is light spectrum. Plants, generally, respond best to a combination of blue and red light, with a little bit of the spectrum in-between. Thanks to a plant biologist named Robert Emerson, we know there are two primary chemical procedures that lead to photosynthesis. These processes are hastened, and more efficient, when the plants (both flowering and non-flowering) are exposed to both blue and red-light spectrums.
Biologically, flowering or fruiting plants (cannabis, many perennials, tomatoes) need the red ends of the spectrum to trigger flowering. That’s because the red end of the spectrum triggers the production of florigen, a hormone that causes plants to flower. You can read more about this phenomenon here.
Modern growers should investigate full-spectrum LED lights that deliver the ideal intensity and spectrum of light to support their crop. Growers growing multiple types of crops, working with complex flowering plants or simply wanting utmost control over product outcomes can also research spectrally tunable lights.
Getting Up Close and Personal
Both nonflowering and flowering plants need a certain amount of photosynthetically active radiation (PAR) in order to perform photosynthesis and survive. When growing indoors, or providing supplemental light to a partially indoor crop, cultivators will want to investigate their lighting fixtures’ PAR to ensure uniformity and efficacy standards are being met.
Commercial growers will often look beyond PAR and calculate their fixtures’ Photosynthetic Photon Flux (PPF) and Photosynthetic Photon Flux Density (PPFD). These provide a clearer understanding of exactly how much PAR is hitting the plant’s leaves each second.
In addition, LED lights run cooler than other lighting technologies, meaning growers can hang the lights much closer to the plant canopy, ensuring all corners of their garden receive adequate light. Distance is among the greatest detriments to uniformity, so cultivators will want to make sure their LEDs are close enough to their crops.
Many growers want to expand their facilities but can’t afford to invest in additional square footage. This goes for cultivators working with leafy greens, microgreens and other edible plants, cannabis cultivators and others. Vertical racking with LEDs makes an expansion possible, without breaking the bank, giving cultivators the opportunity to dramatically expand their yields without sacrificing quality or sustainability.
The urban gardens of the future may rely on the possibilities offered by vertical racking. Already, gardens in densely populated cities are taking advantage of these green skyscrapers – making growing possible, even where the land isn’t viable or available.
Banking on Plant Biology
Plants physically respond to minute changes in the light spectrum. Even if these changes are invisible to the human eye, they mean everything to plants – and can result in bigger, brighter, more fragrant results. Through harnessing the power of photomorphogenesis, cultivators can grow eye-catching, specialty lettuces, plants with bigger, lusher leaves for bountiful salads or more fragrant herbs that go for top-dollar on the market. This can all be accomplished through adjustments in the light spectrum.
In the cannabis world, the possibilities are endless. Expert cultivators have learned to adjust the spectrum to yield a full rainbow of colors in cannabis leaves and dense, trichome-coated buds. Spectral tuning has even been shown to stave off plant diseases and pests, keeping cannabis crops happy and healthy.
Lighting the Way, from Seedlings to Flowering
LEDs can support each step in a plant’s lifecycle, giving them the gentle light they need as seedlings to establish a robust root system and stalks. Then, brighter, more intense (and redder) light can trigger flowering. Because they’re easily adaptable, moveable and sturdy enough for years of use, they make sense for most types of plants, flowering and nonflowering, grown indoors or as supplemental lighting in greenhouses.