How Many Watts of LED Grow Light Do Desktop Plants Need?
Desktop growing is the most common question we get from home growers: “How many watts do I actually need on my desk?”
The quick answer
| Plant type | Watts per square foot (LED) |
|---|---|
| Low-light houseplants (pothos, snake plant) | 10–15W |
| Herbs (basil, mint, parsley) | 15–20W |
| Leafy greens, microgreens | 20–30W |
| Compact fruiting (peppers, cherry tomato) | 30–40W |
For a typical 2 ft × 1.5 ft desktop shelf (3 sq ft) of herbs, you want roughly 45–60W of efficient LED light.
Why watts alone is not the whole story
Efficiency matters more than raw watts. A 20W fixture at 2.2 µmol/J delivers more usable photons than an old 30W fixture at 1.0 µmol/J. Check the µmol/J (efficacy) figure, not just the wattage.
Distance matters
Desktop lights are usually close to the canopy:
- 10–20W fixtures: keep 6–12 inches from leaves
- 20–40W fixtures: keep 12–18 inches
If leaves curl or bleach, raise the light or turn it down — a dimmer saves you both.
Our recommendation
For most desks, a 20–30W dimmable full-spectrum panel is the sweet spot: bright enough for herbs, dim enough for low-light plants. See our 45W–50W panel range or contact us for help sizing a light for your exact shelf.