Oct 07, 2026 / By the Lumibox team / in LED Guides
LED grow lights let you grow vegetables, herbs and flowers all year, whether you start seedlings on a basement shelf, run a grow tent or stretch the season in a greenhouse. A good LED fixture gives plants the wavelengths they actually use, while consuming far less electricity and producing far less heat than HPS, metal halide or fluorescent lamps. Effective greenhouse lighting is no longer reserved for large operations.
This guide is for home growers, hobby and commercial greenhouse owners, and businesses such as cafés and garden centres that keep plants on display. It explains how plants use light, compares the three main formats of LED grow lights, then covers greenhouse and indoor setups, a buying checklist and common questions.
Lumens describe brightness as the human eye sees it and say very little about plant growth, because plants respond to specific wavelengths.
Chlorophyll absorbs mostly blue and red light. Blue, around 450 nm, supports germination and compact, leafy growth, and keeps seedlings from stretching. Red, at 650 or 660 nm, drives photosynthesis, budding and flowering. Red and blue bulbs and strips concentrate their output on those two peaks, hence their pink or magenta glow.
Full-spectrum fixtures emit a broad white light that closely replicates sunlight through the vegetative and flowering stages. Under white light, it is also easier to judge leaf colour and spot pests or deficiencies.
PAR (photosynthetically active radiation) is the band of light plants use, commonly defined as 400 to 700 nm. Three measurements describe it:
Efficacy, in µmol/J, measures plant light per unit of electricity: it is why an LED fixture can match an HPS lamp at the canopy while drawing less power. Target PPFD depends on the crop and its stage; the ranges below are common rules of thumb, not product data.
| Stage or crop | Common PPFD range (µmol/m²/s) |
|---|---|
| Seedlings and cuttings | About 100 to 300 |
| Leafy greens, herbs and microgreens | About 200 to 400 |
| Vegetative growth of larger plants | About 400 to 600 |
| Flowering and fruiting crops | About 600 to 900 |
Low-wattage grow bulbs suit a few plants close to the bulb, strips spread light along shelves, and full-spectrum fixtures reach the higher ranges over a tent or a greenhouse bench.
Photoperiod, the number of hours of light per day, matters as much as intensity. As a common benchmark, growers give seedlings, leafy greens and vegetative plants 16 to 18 hours of light, then switch to 12 hours of light and 12 of darkness to trigger flowering in short-day plants. Plants need their dark period, so use a timer.
Product instructions come first: the A19 9W LED Grow Light runs up to 16 consecutive hours in a windowless room, or a maximum of 8 hours in a row followed by 4 hours off when the plant also gets sunlight.
Most setups call for one of three formats, depending on the space, the crop and how the light will be mounted.
A grow bulb threads into a table lamp, clamp lamp, pendant, track head or recessed can you already own, with no driver or ballast. Two grow bulbs listed with the A19, A21 and E26 LED bulbs combine 450 nm blue and 650 nm red, run on 110 to 130 V, operate from -20 to 50 °C and are rated for damp locations from 40 to 85% relative humidity, which suits propagation areas and greenhouse benches.
The BR30 aims its light down onto a seed tray; the A19 spreads it sideways over a shelf of herbs. The BR30 dims with a compatible dimmer (check compatibility among the LED dimmers), while the A19 works best on a plug-in timer.
On seed-starting shelves, microgreens racks and propagation cabinets, a strip spreads light evenly instead of creating one hot spot. The LED Strip Horticultural 16W/M, listed with the indoor LED strips, carries 660 nm red and 450 nm blue diodes on a 24 V DC circuit, with IP54 protection against splashes and dust.
It needs a 24 V DC driver from the power supplies, never a direct connection to line voltage: multiply 16 W by the number of metres, then leave headroom. Feed long runs from both ends, cut only at the printed marks, and mount the strip in an aluminum LED channel to keep it cooler. The guide on how to choose LED strip lights covers voltage and power supplies in detail.
For grow tents, grow rooms and greenhouse benches, a full-spectrum fixture provides the intensity that bulbs and strips cannot. Four are listed with the LED floodlights: the 400W Grow Light, two canopy-style grow lights including the 720W Grow Light, and a greenhouse model. All four use passive cooling through aluminum housings and heat sinks, with no fans to maintain, and carry cUL and CSA certification.
| Format | Best for | Key specs |
|---|---|---|
| E26 grow bulb | Seedlings, herbs, a few pots | 9 W or 10 W, PPF of 9 or 8.5 µmol/s, damp locations |
| Horticultural LED strip | Shelves, racks, cabinets | 16 W/m, 24 V DC, IP54 |
| Full-spectrum grow fixture | Grow tents, basements, grow rooms | Passive cooling, hanging hardware, cUL and CSA |
| Greenhouse fixture | Greenhouses, very humid spaces | Wet locations, daisy-chain wiring, rail or hanging mounts |
In Canada, winter days are short and often grey, so a greenhouse rarely gets enough natural light from late fall to early spring. Supplemental LED greenhouse lighting lengthens the day and adds intensity on cloudy days, which keeps seedlings compact.
Watering, misting and condensation make humidity the main challenge, so look for a wet-location rating rather than a damp-location one. The 640W Green House Light is IP-rated for wet locations and certified cUL and CSA. Its mounting system suits overhead rails and adjustable hanging kits, and daisy-chain connectivity links several units along a bench without complicated wiring. Its full-spectrum light, with a high CRI, also makes plant health easy to read.
In a commercial greenhouse, aim for uniform PPFD across the benches: several fixtures at regular spacing beat one powerful unit. Have a licensed electrician size the circuits, and control the system with a timer or controller. Compared with HPS and metal halide, LED greenhouse lighting systems provide equal or greater usable light at the canopy with substantially less electricity and less heat. The guide to LED lighting ROI for Canadian businesses explains how to estimate the savings.
Programmable control lets lights follow a schedule and dim as the crop changes stage. The 720W Grow Light has a driver designed for optional external lighting controllers that program schedules and dimming levels, and an IP-rated enclosure built for humid grow rooms and hobby greenhouses. A simple timer handles a fixed daily cycle.
Indoors, the fixture is the only light source, and a basement or a tent traps humidity, so every grow light in this guide is built for damp or humid conditions.
Raise the light if leaves bleach or curl, lower it if seedlings stretch and turn pale, and keep air moving inside the tent. For the rest of a finished basement, see LED basement lighting.
For most growers, yes. An LED fixture turns more of its energy into usable plant light, produces less heat at canopy level and consumes substantially less electricity than HPS or metal halide for equal or greater usable light.
Yes. The driver of the 720W Grow Light works with optional external lighting controllers, and any fixture can run on a timer.
A common benchmark is 16 to 18 hours for seedlings and leafy greens, and 12 hours for short-day plants in flower, always followed by a dark period. Follow the product's instructions: the A19 9W LED Grow Light runs up to 16 consecutive hours in a windowless room.
Start with the manufacturer's recommendation, then adjust. Raise the light if leaves bleach or curl, and lower it if seedlings stretch and turn pale; adjustable hanging cables make this easy.
A regular white LED bulb can keep a houseplant going, but it is engineered for human eyes. A grow bulb concentrates its output at 450 nm and 650 nm, where chlorophyll absorbs most.
Yes. The full-spectrum grow fixtures carry cUL and CSA certification, and the A19 and BR30 grow bulbs are cULus certified. Check the location rating too: damp, wet or IP54.
Ready to light your growing space? Start with the grow fixtures listed with the LED floodlights, or browse the LED bulbs for a grow bulb that fits the lamps you already own.
