Balcony Lighting for Herbs and Vegetables 2026

Most balcony gardening guides assume you have a south-facing terrace with six hours of direct sun. Most apartment balconies don’t. A north-facing balcony in a city centre, a lightwell-adjacent terrace, or a west-facing balcony shaded by the building opposite — these are the real conditions most urban renters are dealing with.

Lighting determines what you can grow and how much you harvest. This guide covers how to measure what you have, what it means for your plant choices, and when and how to supplement with grow lights — with real cost figures for both the US and European markets.

Table of Contents

• How Much Light Does Your Balcony Actually Get?
• Light Requirements by Herb and Vegetable
• When You Need a Grow Light (And When You Don’t)
• Best Grow Lights for Balconies and Covered Terraces
• How to Mount Grow Lights Without Drilling
• Electricity Cost: What It Actually Adds to Your Bill
• My Experience Supplementing Light on a West-Facing Balcony
• FAQ

How Much Light Does Your Balcony Actually Get? {#measuring-light}

“Low light” means different things to different plants. The practical framework is hours of direct sun per day plus ambient lux at plant height during the remaining hours.

How to measure it: A free lux meter app on your phone (Lux Light Meter Pro, available for both iOS and Android) gives a directional reading. Hold the phone camera-up at plant canopy height and take readings at three times: 9am, 12pm, and 3pm on a clear day. Average the three readings.

The direction your balcony faces is the primary determinant of what you can grow. Orientation is harder to compensate for than you think — reflective surfaces and grow lights help, but a north-facing balcony in October is not going to produce tomatoes.

Light Requirements by Herb and Vegetable {#light-requirements}

The practical summary: Mediterranean herbs (basil, rosemary, thyme) need your sunniest position and fail in shade. Cold-climate crops (lettuce, spinach, mint, parsley, chives) tolerate north-facing or shaded balconies well. Fruiting vegetables (tomatoes, peppers, courgette) require 6+ hours of direct sun — don’t attempt them on shaded balconies without grow lights.

When You Need a Grow Light (And When You Don’t) {#when-grow-light}

You don’t need a grow light if:
– Your balcony gets 5+ hours of direct sun and you’re growing herbs or leafy greens
– You’re only growing mint, parsley, chives, or lettuce on a partially shaded balcony
– It’s April through August in a sunny location (natural light is sufficient)

You do need a grow light if:
– You want to grow basil, tomatoes, or peppers on a north-facing or heavily shaded balcony
– You’re trying to start seeds indoors in January–March (window light is insufficient for strong seedlings)
– You want to extend the growing season into November–February
– Your balcony faces a lightwell or gets less than 3 hours of sun

The threshold where grow lights become worth it: if your balcony registers under 5,000 lux at midday and you want to grow anything beyond shade-tolerant herbs.

Best Grow Lights for Balconies and Covered Terraces {#best-grow-lights}

For herbs and leafy greens (budget option)

A basic LED grow strip or compact panel — GE BR30 Full Spectrum LED (around $20 / €18), Sansi 15W Full Spectrum Bulb ($18 / €16), or a clip-on LED panel (Mars Hydro SP-150, $35 / €32) — is sufficient for one shelf of herbs. Run for 14 hours per day.

For herbs plus fruiting plants

You need at least 50W true draw. The Mars Hydro TS 600 ($55 / €50) and Viparspectra P600 ($60 / €55) cover approximately 30 × 60cm adequately for herbs and dwarf tomatoes. Check for the true wattage draw (listed in specs), not the “equivalent” wattage — a “600W equivalent” LED typically draws 100W actual, which is what matters for your electricity bill.

For a covered balcony with weather exposure

Any light fixture rated IP65 or higher is safe for covered outdoor use (protected from rain spray and condensation). Most indoor grow lights are rated IP40 — fine for a covered terrace with no direct rain, but not suitable for an open balcony where rain can reach the fixture. Check the IP rating before mounting outside.

Practical mounting options (no drilling required)

All of these are renter-friendly — no wall damage, no landlord conversation required.

Electricity Cost: What It Actually Adds to Your Bill {#electricity-cost}

A 45W LED panel running 14 hours/day uses 0.63 kWh per day.

• US average rate (~$0.16/kWh): approximately $3.00/month
• European average rate (~€0.28/kWh): approximately €5.30/month

Running two panels for a full herb shelf:
– US: ~$6/month
– Europe: ~€10–11/month

At European electricity prices, one grow light adds roughly the cost of a bunch of supermarket basil per month to your bill — but produces continuous harvests instead of one bunch. The payback calculation still works; it just takes a little longer in Europe than in the US.

Use a programmable outlet timer ($8–$12 / €7–€10) to automate the light schedule. Plants need a dark period — never run grow lights 24/7.

My Experience Supplementing Light on a West-Facing Balcony {#my-experience}

My balcony faces west and is partially shaded by an adjacent building until around 2pm, giving me approximately 3.5 hours of direct afternoon sun. Peak midday lux at plant height: 12,000–18,000 lux in summer, dropping to 4,000–7,000 in October.

In 2024 I grew basil directly in that light without supplementation. The plants lived but didn’t thrive — stems were leggy, new growth was slow, and flavour was noticeably weaker than shop basil. I was harvesting about 20g per week from two pots.

In spring 2025 I added a 45W LED panel (Mars Hydro SP-150, €42 from Amazon.de) on a clip mount to the balcony railing, running 14 hours/day via a timer. In the same two pots with the same watering and fertiliser routine, weekly basil yield increased to 55–70g. The leaves were darker green and noticeably more aromatic.

What I got wrong: I positioned the light too high initially — about 50cm above the canopy — thinking I’d get better coverage. At that distance, the light intensity at plant level was insufficient. Moving it to 20–25cm above the canopy made the difference. Measure the manufacturer’s recommended distance rather than guessing.

The morning light finding: I’d assumed the 14-hour LED schedule could start at any time. Running it from 6am to 8pm (overlapping with natural afternoon light) produced better results than running it 10pm to noon, which gave the plants simulated “morning” at midnight. Plants seem to respond to light in phase with natural temperature cycles, even if the light is artificial.

For related guides, see growing food in a windowless apartment and the balcony plant calendar for timing your growing season.

Safety Disclaimer

Grow lights not rated for outdoor use (IP40 or lower) must be used on fully covered balconies only. Direct rain or heavy condensation on an indoor-rated fixture creates an electrical hazard. Ensure all outdoor extension cords and power strips are rated for outdoor use (IP44 minimum). Keep grow lights at manufacturer-recommended distances from plants — too close causes light burn (pale, bleached patches). Don’t look directly into LED grow panels during operation; they emit UV wavelengths.

FAQ

What type of grow light is best for balcony herbs?
Full-spectrum LED panels are the most energy-efficient option. They cover the red (630–660nm) and blue (430–460nm) wavelengths plants use, without generating the heat of HPS or fluorescent alternatives. For herbs and greens, a 20–45W panel is sufficient. For fruiting plants (tomatoes, peppers), use at least 50–100W true draw.

How many hours of artificial light do herbs need?
Leafy herbs (mint, chives, parsley, lettuce): 12 hours/day. Mediterranean herbs (basil, rosemary, thyme): 14 hours/day. Fruiting plants (tomatoes, peppers): 16 hours/day. Always include a dark period — running lights 24/7 doesn’t help and can cause light stress.

Are grow lights safe to use outdoors?
Only if rated for outdoor use (IP65 for full weather protection, IP44 for splash protection on a covered balcony). Standard indoor grow lights (IP40 or lower) are not waterproof and should only be used on fully covered, enclosed balconies where rain cannot reach them.

Will grow lights noticeably increase my electricity bill?
A 45W panel at 14 hours/day adds approximately $3/month (US) or €5.30/month (Europe) to your bill. Running two panels for a full herb shelf: $6/month US or €10–11/month Europe. This is offset by the cost of not buying fresh herbs at the supermarket.

Can I use any LED bulb as a grow light?
Standard warm white LED bulbs don’t provide the full spectrum plants need — they’re heavy in green wavelengths, which plants reflect rather than absorb. Use bulbs specifically labelled as “full spectrum” or “grow light.” These emit more blue and red wavelengths. Look for 5000K–6500K colour temperature as a minimum guide; proper grow lights also list PPFD output in their specifications.

How close should a grow light be to plants?
This varies by light power, but general guidelines: LED strips and low-power panels (under 25W): 10–20cm. Mid-power panels (25–100W): 20–40cm. High-power panels (100W+): 40–60cm. Too close causes light burn (bleached patches); too far reduces effective PPFD to below the threshold for productive growth. Check the manufacturer’s recommendation for your specific model.