Windowsill herbs and seedlings that grow tall, thin and pale in winter are not getting enough light.
For one pot, start with the SANSI 10W clip-on: it clamps to the pot rim and switches itself off on a built-in timer. A row of pots or a tray of seedlings needs a bar light instead.
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The five lights, at a glance:
- SANSI 10W clip-on grow light: one herb pot or houseplant, clamped to the pot, with a timer.
- FECiDA 27W three-head clip grow light: three or four pots grouped on a desk or a shelf.
- Barrina T5 1 ft grow light bars, 4-pack: a windowsill row, or plants on the shelf below another shelf.
- Barrina T5 2 ft grow light bars, 4-pack: a seed-starting shelf with trays.
- Aokrean halo grow light with base: one larger houseplant with no edge nearby to clip a light to.
SANSI 10W clip-on grow light
One pot of herbs or one houseplant on a windowsill that is too dim in winter.
SANSI 10W Pot Clip-On Grow Light
Bendable gooseneck on a clamp that fits a pot
3, 6 or 12-hour timer, 4 brightness levels
Check the Amazon price
SANSI builds this light to clamp onto the pot itself, on a bendable gooseneck, so it needs no shelf, stand or wall.
The built-in timer runs it for 3, 6 or 12 hours and then repeats that cycle every day, so you set it once.
It dims in four steps, from 25 to 100 percent. It is one head on one clamp, so it lights the pot it sits on. Two pots side by side need two of these, or the FECiDA.
- Works well for
- A light that turns itself on and off every day, for 3, 6 or 12 hours
- Not needed if
- A full seed tray (that is the Barrina 2 ft bars)
FECiDA 27W three-head clip grow light
Three or four small pots grouped together on a desk, a table or a plant shelf.
FECiDA 27W Clip Grow Light, 3 Heads
Three 9 W heads
Clamps to a shelf, a tabletop or a flat panel
Check the Amazon price
FECiDA rates the three-head version for 3 to 4 potted plants on a desk or plant shelf. Each head is a 9-watt tube, which is where the 27 watts comes from.
It clamps to a flat edge rather than a pot, and its three heads spread over a small group. FECiDA’s feature list names no timer, so plan on a plug-in outlet timer to switch it on and off.
- Works well for
- Clamping to the edge of a shelf or table rather than to a pot
Barrina T5 1 ft grow light bars, 4-pack
A row of pots along a windowsill, or plants on a shelf with another shelf above them.
Barrina T5 1 ft Grow Light Bars, 4-Pack
Four 1 ft bars, 20 W together, linkable
Tape, clips and cable ties in the box
Check the Amazon price
Barrina sells four 1-foot bars that draw 20 watts together and link into one run. Laid end to end, that is four feet of light, enough for a long sill or two short rows.
A bar has to sit above the plants, so it needs the underside of a shelf, a cabinet or a frame. Barrina says not to mount the bars on fresh plaster or on dusty, greasy or rough surfaces.
Barrina’s parts list has on/off switches and no timer.
- Works well for
- Four short bars that link end to end, each with its own switch
- Not needed if
- A spot with nothing above the plants to fix a bar to
Barrina T5 2 ft grow light bars, 4-pack
A seed-starting shelf with trays of tomato, pepper or herb seedlings.
Barrina T5 2 ft Grow Light Bars, 4-Pack
Four 2 ft bars, 40 W together (4 x 10 W)
Separate switch on each bar
Check the Amazon price
These bars are twice the length of the 1-foot ones. Barrina lists four 10-watt bars, 40 watts together, with a switch on each so you can light one tray or all of them.
Seedlings need the light close and on for most of the day, which a bar fixed above a tray does well.
Fix the bars under the shelf above. Then raise the tray on an upturned box to bring the seedlings up to the light.
- Works well for
- Growing the setup later: Barrina says up to 16 bars link in one run
- Not needed if
- One or two pots (the 1 ft bars or a clip-on cover those)
Aokrean halo grow light with base
One larger houseplant on the floor or a table, with no shelf or window ledge to clamp to.
Aokrean Halo Grow Light with Base
Pole extends up to 26 in, 10 brightness levels
3, 9 or 12-hour timer, 3 light colors
Check the Amazon price
Aokrean’s stand is a flat base that the pot sits on, and Aokrean notes the base needs the pot’s weight on it to stay steady. The stake can also go straight into the soil instead.
The ring sits on a pole that extends up to 26 inches, so it can rise as a plant grows taller.
The timer has 3, 9 and 12-hour settings. It plugs in; it does not run on a battery.
- Works well for
- A pot with nothing nearby to clip to: the pot stands on the light's base
- Not needed if
- A row of pots (the ring lights the one plant under it)
Which light fits your space
A clip-on needs an edge, a bar needs something above the plants, and a halo needs only the pot. Find your setup in the table.
| Your pots and space | Start with this |
|---|---|
| One pot of herbs or a houseplant on a sill | SANSI 10W clip-on grow light |
| Three or four pots on a desk or a shelf | FECiDA 27W three-head clip grow light |
| A row of pots along a windowsill or under a shelf | Barrina T5 1 ft grow light bars, 4-pack |
| A shelf of seed trays | Barrina T5 2 ft grow light bars, 4-pack |
| One larger plant with nothing to clamp to | Aokrean halo grow light with base |
How close, and how many hours a day
Seedlings want the light 2 to 6 inches above them for 14 to 16 hours a day.
That is the advice of the University of Maryland Extension, the university’s public advice service for home gardeners. It also says to run the lights on an outlet timer.
Closeness matters because light fades fast. Maryland says its strength decreases rapidly with increasing distance from the plant.
Houseplants and herbs that also sit in a window have a different limit:
- Count daylight and lamp light together. Maryland says to give plants no more than 16 hours of light a day in total, because most plants need a dark period.
- The built-in timers stop at 12 hours. That is the longest setting on the SANSI and the Aokrean. Set it to run through the daylight hours, and lamp plus window stay within 16.
- Seedlings under lights alone need the longer day. Neither built-in timer reaches 14 hours, so a seed shelf runs on a plug-in timer instead.
A basic model is enough, and you can compare plug-in outlet timers on Amazon. If you are starting seeds, when to start each crop indoors tells you the week the lights need to go on.
What is worth paying for
A timer and a shape that fits the space matter as much as wattage. How close the light sits changes how much reaches the plant.
Worth paying for
- A timer, built in or plugged in, so the light keeps the same hours every day.
- A shape that matches the space: a clamp for one pot, bars for a row.
- A switch on each bar, so one tray can be lit without the rest.
Not worth paying for
- “Replaces a 120 W bulb” claims, which compare the light with an old bulb and say nothing about how much reaches your plant.
- More watts than the space needs, when moving a light closer gives the plant more of it.
- Purple red-and-blue light, when a white light sold as full spectrum lets you see the plant’s true color.
Maryland says red, far-red and blue light all matter for plant growth, and to supply all three.
When a window is enough
You may not need a light at all. Maryland’s light table puts snake plant, ZZ plant and peace lily in low light, the kind a north-facing window gives.
The University of Florida’s gardening service for homeowners says a north-facing window may never reach even 400 foot-candles, a common unit of light. Plants that want more than that need a brighter window or a lamp.
Maryland names the signs of too little light: plants stretch and turn leggy, lean toward the window and fade in color.
A pot of herbs on a kitchen windowsill that stays compact and green is probably getting enough light.
Which one to buy, by what you are growing
- One herb pot or houseplant: the SANSI 10W clip-on, with its own timer.
- A small group on a desk or shelf: the FECiDA three-head clip light, on a plug-in timer.
- A windowsill row or a shelf of plants: the Barrina 1 ft bars.
- Seed trays in late winter: the Barrina 2 ft bars, 2 to 6 inches above the seedlings.
- One big plant in a corner: the Aokrean halo, standing under the pot.
