The Best Grow Lights for Winter
Winter takes hours away as much as it takes intensity. The fix is usually a modest fixture on a long timer, not a big one.
By Scooter M. — An enthusiast who's genuinely into this. I read the manuals, compile the published specs, and do the math. No lab coat.
Published · How we pick
Photographs on this site are licensed stock and are illustrative of the fixture type. We do not own the units we write about.
How this page is funded: the buy links here are Amazon Associates links, and we earn a commission on qualifying purchases at no extra cost to you. We have not been paid to feature anything on this page, we accept no free product, and commission plays no part in the ranking. Full disclosure.
We have not tested these units. Everything below comes from the manufacturer’s own published specifications, or from arithmetic we have shown our working for. Where a figure is not published, we say so instead of estimating one. Read the method.
Quick picks
Efficacy is photons out per joule in. Where a manufacturer publishes it we quote theirs; where they publish photon output and wattage but not efficacy, we divide and label it as ours; where they publish neither, the cell says so rather than guessing. Tap a row for the full write-up.
| # | Product | Best for | Efficacy | Price |
|---|---|---|---|---|
| 1 |  Barrina T5 4ft Grow Light Strips The default seed-starting bar for good reasons — 4 ft long, linkable in series, cheap per foot — and the reason we built a coverage calculator, because Barrina publishes no photon data whatsoever. | A window shelf | Not published | |
| 2 |  SANSI 36W BR30 Grow Light Bulb The rare grow bulb that publishes both PPF and a PPFD figure with the measurement distance attached, which is the only reason it can be sized honestly. | One plant, retrofit | 1.82 umol/J (ours) | |
| 3 |  Soltech Aspect Gen 2 The only fixture here you would willingly hang in a living room, and the only one publishing PPFD at three separate distances so it can actually be placed by the numbers. | A living-room specimen | 1.39 umol/J (ours) | |
| 4 |  VIVOSUN VS1000 Samsung LM301 diodes and a published 2.75 umol/J — the highest efficacy claim on this list, though the photon output it implies is never printed anywhere. | A dense plant group | 2.75 umol/J |
The reasoning
The winter problem is usually misdiagnosed as “my window is too dark”. It is more precisely: the day is too short, and the light that does arrive is weaker and grayer. Those multiply. Daily light integral captures both at once, which is why it is the right frame for a seasonal fix.
The practical consequence is important and cuts against instinct: the usual answer is not a brighter fixture. It is a modest fixture running longer. Because DLI is intensity multiplied by hours, adding six hours at the front and back of a short day recovers a large fraction of what the season removed, for very little power.
A plant receiving 100 µmol/m²/s from a window for 8 useful winter hours: DLI = 100 × 8 × 3600 ÷ 1,000,000 = 2.9 mol/m²/day. Below even the low-light band.
Option A — double the intensity for the same 8 hours: 200 × 8 × 3600 ÷ 1,000,000 = 5.8 mol/m²/day.
Option B — keep 100 µmol/m²/s but supplement to 16 hours: 100 × 16 × 3600 ÷ 1,000,000 = 5.8 mol/m²/day. The same result.
Option B is far cheaper to buy, because a fixture producing 100 µmol/m²/s over a shelf costs a fraction of one producing 200. You pay a little more in hours, and hours are cheap.
How to run a winter supplement
- Put it on a timer, 12 to 16 hours. University of Minnesota Extension gives 12 to 14 hours for foliage houseplants and 14 to 16 for flowering ones. Set it once in November and forget it.
- Run it at the ends of the day, not the middle. Two hours before dawn and four after dusk extends the photoperiod; running at midday just adds to light the plant already has.
- Get it close. Intensity falls with roughly the square of distance. Six inches of adjustment does more than a fixture upgrade.
- Turn it down again in March. The supplement is for the season. Leaving a shelf lit 16 hours a day in June wastes electricity and can push plants harder than you want.
What a winter of it costs
| Fixture | Draw | kWh over the season | Season cost |
|---|---|---|---|
| GooingTop clip light | 10 W | 21.0 | $3.85 |
| SANSI 36W bulb | 36 W | 75.6 | $13.86 |
| Soltech Aspect Gen 2 | 36 W | 75.6 | $13.86 |
| Barrina, 4 linked bars | 80 W | 168.0 | $30.81 |
| VIVOSUN VS1000 | 100 W | 210.0 | $38.51 |
| AC Infinity IONBOARD S22 | 115 W | 241.5 | $44.29 |
Arithmetic: watts × 14 hours × 150 days ÷ 1000 = kWh, × $0.1834. The rate is the US residential average from the EIA’s Electric Power Monthly for June 2026; substitute yours in the cost calculator.
The whole-season numbers are the useful ones here, and they are smaller than most people expect — under $14 to keep a specimen plant growing from November to March. The longer treatment is in what it costs to run a grow light all winter.
Picking between these four
A window shelf of several plants is a linear problem, so linked bars are the right shape — one run along the shelf lights everything on it. That is why Barrina leads here despite publishing no photon data at all: nothing else matches a shelf as cheaply per foot.
One plant you already have a lamp for is the SANSI bulb: 65.6 µmol/s published, 265.58 µmol/m²/s at 1 ft, and no new hardware. One plant in a room you look at is the Soltech, with the efficiency caveat stated plainly on our indoor plant roundup. A dense group in a corner is where a 100 W panel finally earns its keep.
Every pick in full
Barrina T5 4ft Grow Light Strips
LED barA window shelf
The default seed-starting bar for good reasons — 4 ft long, linkable in series, cheap per foot — and the reason we built a coverage calculator, because Barrina publishes no photon data whatsoever.
What Barrina publishes
- Power draw
- 20 W per fixture; an 8-pack draws 160 W (source)
- Spectrum
- 5000 K (source)
- Dimming
- No; on/off switch per fixture, linkable up to 8 in series (source)
- Dimensions
- 4 ft strip, 120-degree beam angle, 120 V AC (source)
What Barrina does not publish
- PPF in umol/s — for any strip in the range
- PPFD at any stated distance
- Photon efficacy in umol/J
- LED count per strip, and rated lifespan
Who should skip it
Skip it if you need to know what you are getting before it arrives. There is no published PPF, no PPFD and no efficacy figure, so nothing about its output can be verified in advance.
SANSI 36W BR30 Grow Light Bulb
Grow bulbOne plant, retrofit
The rare grow bulb that publishes both PPF and a PPFD figure with the measurement distance attached, which is the only reason it can be sized honestly.
What SANSI publishes
- Power draw
- 36 W (source)
- PPF (photon output)
- 65.6 umol/s (source)
- PPFD
- 265.58 umol/m2/s at 1 ft (source)
- Spectrum
- 4000 K, 400-780 nm, CRI close to 100 (source)
- Rated life
- 25,000 hours (source)
Our arithmetic
- Efficacy, computed from the published figures: 1.82 umol/J
65.6 umol/s / 36 W = 1.82 umol/J. That is roughly a third less efficient than the panels on this page — the price of a screw-in form factor. - Electricity used at 12 hours a day for 30 days: 12.96 kWh a month
36 W x 12 h x 30 d / 1000 = 12.96 kWh.
What SANSI does not publish
- Beam angle
- Fixture dimensions
Who should skip it
Skip it if you are lighting more than one plant. 65.6 umol/s is a small amount of light spread over a cone — it lights a single specimen, not a shelf.
Soltech Aspect Gen 2
PendantA living-room specimen
The only fixture here you would willingly hang in a living room, and the only one publishing PPFD at three separate distances so it can actually be placed by the numbers.
What Soltech publishes
- Power draw
- 36 W (source)
- PPF (photon output)
- 50 umol/s (source)
- PPFD
- about 50 umol/m2/s at 1 m, 34.9 at 4 ft, 15.5 at 6 ft (source)
- Spectrum
- 3000 K warm white, CRI 98 (source)
- Dimming
- Yes, in-line dimmer 10-100% (source)
- Dimensions
- 3.5 x 3.5 x 6.2 inches (source)
- Rated life
- 50,000 hours (source)
Our arithmetic
- Efficacy, computed from the published figures: 1.39 umol/J
50 umol/s / 36 W = 1.39 umol/J. Roughly half the efficacy of a 2.7 umol/J board — the design premium is paid twice, once at purchase and again every month on the meter.
Who should skip it
Skip it if photons per watt is the metric that matters. At 50 umol/s from 36 W it is the least efficient fixture on this page, and much of the price is industrial design.
VIVOSUN VS1000
LED panelA dense plant group
Samsung LM301 diodes and a published 2.75 umol/J — the highest efficacy claim on this list, though the photon output it implies is never printed anywhere.
What VIVOSUN publishes
- Power draw
- 100 W (source)
- Efficacy
- 2.75 umol/J (source)
- Stated coverage
- 2 x 2 ft (source)
- Spectrum
- 380-780 nm, including 660 nm and 730 nm; 3000 K and 5000 K (source)
- Diodes
- Samsung LM301 (source)
- Dimming
- Yes, four dimming levels, daisy chain (source)
Our arithmetic
- Photon output implied by the published wattage and efficacy: about 275 umol/s
100 W x 2.75 umol/J = 275 umol/s. Our arithmetic from VIVOSUN's two published figures, not a VIVOSUN figure.
What VIVOSUN does not publish
- PPF in umol/s
- PPFD at any stated distance
- Rated lifespan
Who should skip it
Skip it if you want the efficacy claim independently checkable. With no published PPF there is no second figure to divide against, so the number has to be taken on trust.
Questions people actually ask
+Do houseplants need grow lights in winter?
+Should I run a winter grow light brighter or for longer?
+When should I start and stop supplementing?
+What does a winter of supplemental light cost?
Sources
- University of Minnesota Extension — Lighting for indoor plants and starting seeds — consulted September 2, 2026
- Iowa State University Extension — Important Considerations for Providing Supplemental Light to Indoor Plants — consulted September 2, 2026
- US Energy Information Administration — Electric Power Monthly, Table 5.3 (US residential average, June 2026) — consulted September 2, 2026
- SANSI — BR30 36W grow light bulb product page — consulted September 2, 2026
- Soltech — Aspect Gen 2 published specifications — consulted September 2, 2026
- VIVOSUN — VS1000 product page — consulted September 2, 2026
Read next
Houseplants
Winter Daylight Loss, and What to Add Back
Why the winter deficit compounds, and how to size the supplement that closes it.
Running Cost
The Cost to Run a Grow Light All Winter
Five setups priced for a full winter season, from a clip light to a three-shelf rack.
Houseplants
How Much Light Do Houseplants Need in Winter?
Published DLI bands by plant type, and how to work out what your winter window is short by.
Houseplants
The Best Grow Lights for Indoor Plants
Sized to a 3-10 mol/m2/day houseplant target rather than a grow-tent target, with running cost for each.
Where this sits
This page belongs to Grow Lights for Houseplants and Winter. Every figure on it is either quoted from a named published source or derived in view — the full method is on our methodology page, and how the site is funded is on the affiliate disclosure.