Countertop HarvestBy the Countertop Harvest team · Last updated
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Why do herbs struggle in winter?
Light is usually the limiting factor indoors, and winter makes it worse. Iowa State Extension notes that most herbs want eight or more hours of direct light a day indoors, and that "providing enough light for herbs to grow well indoors is difficult, especially during the winter months when days are shorter." Penn State Extension says most herbs need about 6 hours of direct sun. Herbs that get less become thin and spindly, with smaller leaves and weaker aroma. Cold glass is the other winter problem: basil can't survive temperatures below 50°F, so keep it off chilly windowsills at night.
How much grow light do winter herbs need?
- Hours: Iowa State recommends putting lights on a timer for 12–16 hours a day. Penn State suggests 14–16 hours under fluorescent tubes. Plants still need a dark period, so don't run the light 24/7.
- Distance: fluorescent fixtures go about 6–12 inches from the leaves. LEDs can often sit 12–24 inches away depending on strength (Iowa State). Modern Sprout recommends 10–16 inches above established plants for its fixtures. Follow your light's instructions.
- Type: look for a full-spectrum LED. White full-spectrum light works for herbs and doesn't turn your kitchen purple.
- Adjust by symptom: stretching or pale growth means the light should come closer or be stronger. Bleached or scorched leaves mean it should move further away.
Winter grow light setups compared
| Setup | Example | Best for | Watch out for |
|---|---|---|---|
| Under-cabinet LED bar | Modern Sprout Smart Growbar (15" bar) | A row of herb pots under a shelf or cabinet | Lights a row, not a big area; app needs 2.4 GHz Wi-Fi (manual switch included) |
| Countertop grow light with planter | Modern Sprout Smart Growhouse | 3–4 small plants as a display piece | Small capacity for the footprint |
| Smart garden, soil pods | Click & Grow Smart Garden 3 (8W light) | Silent, low-effort basil on a narrow counter | 3 pods; proprietary pods |
| Hydroponic kit with light | LetPot LPH-Air (10 pods, 24W, 14" light) | Several herbs at once with light and water handled | Has a pump; needs plant food |
| Clip-on or budget LED | See our under-$50 guide | One or two pots on a budget | Coverage and build vary widely |
Specs from the makers' product pages, checked October 2026.
Our picks for winter herbs
Modern Sprout Smart Growbar
A slim 15-inch full-spectrum LED bar that mounts under a shelf or cabinet. Modern Sprout says it suits a row of herbs or a seed tray, not a whole plant wall. It runs a warm 4000K white with app scheduling and a manual on/off switch.
Modern Sprout Smart Growhouse
A metal-frame countertop light with a watertight planter built in, holding 3–4 small plants under dimmable full-spectrum LEDs.
Click & Grow Smart Garden 3
Three pre-seeded soil pods with an 8W light on extension arms and passive watering, so there's no pump. Click & Grow lists it at about 5" deep and estimates around 3.8 kWh a month.
LetPot LPH-Air
A 10-pod hydroponic garden with a 24W full-spectrum light that rises to 14", app scheduling and water alerts. For more models see our LetPot review.
Winter setup checklist
- Set the timer for 12–16 hours of light a day.
- Place the light close to the leaves, at the distance its maker recommends, and raise it as the plants grow.
- Move basil away from cold glass at night (keep it above 50°F).
- Water by touch. Plants under lights in warm rooms may dry out faster.
- Rotate pots weekly if light hits from one side.
Leggy basil already? See why indoor basil dies. On a tight budget, start with our grow lights under $50 guide, or compare built-in-light gardens in best smart gardens for small kitchens.
Sources
- Iowa State Extension: providing more light for herbs indoors
- Iowa State Extension: setting up supplemental lights
- Penn State Extension: growing herbs indoors
- Modern Sprout grow lights
- Click & Grow Smart Garden 3
- LetPot LPH-Air
Frequently asked questions
How many hours of grow light do herbs need in winter?
Iowa State Extension recommends a timer set for 12 to 16 hours a day. Penn State suggests 14 to 16 hours under fluorescent lights.
How far should a grow light be from herbs?
Fluorescent fixtures go about 6 to 12 inches from the leaves, and LEDs often 12 to 24 inches depending on strength. Follow your light's instructions.
What is the best grow light for herbs under a cabinet?
A slim full-spectrum LED bar, such as the 15-inch Modern Sprout Smart Growbar, suits a row of herb pots under a shelf or cabinet.
Can basil stay on a windowsill in winter?
Penn State Extension notes basil cannot survive below 50°F and should not be kept on windowsills during winter.
Do I need a purple grow light?
No. A white full-spectrum LED works for herbs and blends in with normal kitchen lighting.