If you’re wondering how to set up grow lights indoors, this beginner-friendly UK guide walks you through everything step-by-step.
We’ll look at how to choose the right location, how high to hang your light, and how to set timers so your plants get the perfect amount of light each day. With the right setup, you can grow herbs, salads, chillies and vegetables all year round, even through the darker winter months.
For a broader overview of grow light types, setup, and indoor use, see our Grow Lights UK complete guide, which also links out to more detailed deep-dive articles on topics like light spectrum, distance, and timing.
🧰 What You’ll Need (Simple Checklist)
You don’t need everything here, but these basics make indoor grow light setups smooth:
- A grow light (LED panel, strip, or bulb)
- Something to hang or stand it on (tripod, rope ratchets, shelving unit)
- A plug-in timer (mechanical or smart)
- Tape measure
- Optional: reflective surfaces, small grow tent, light meter app
📍 Step 1: Choose the Right Spot
A good location makes indoor growing far easier. Look for:
- Stable temperature
- No strong draughts
- A nearby plug socket
- Some airflow (cracked window or small fan)
Avoid radiators, damp sheds, or bright hot windows that cause glare.
📏 Step 2: Hang Your Grow Lights at the Right Height
General height guidelines:
- LEDs: 12–24 inches (30–60 cm) above plants
- Fluorescent/T5: 6–12 inches
Use ratchet hangers for easy adjustments.
Too high: leggy, weak plants
Too close: scorched or bleached leaves
Hand test: if it feels too warm on your hand, it’s too warm for seedlings.
Step 3: Add a Timer (Set and Forget)
⏱️ Step 3: Add a Timer (Set & Forget)
Timers make your grow light setup consistent and efficient.
Recommended light cycles:
- Seedlings: 16–18 hours
- Leafy greens/herbs: 14–16 hours
- Fruiting plants: 12 on / 12 off once flowering
A mechanical timer is fine, but smart plugs or smart power strips work too
📈 Step 4: Adjust Your Lights as Plants Grow
Lights must move as plants grow.
- Raise the light gradually
- Rotate pots/trays for even light
- Watch for plant signals
Pale/leggy: increase light or lower the fixture
Crispy edges: raise the light or reduce intensity
You can use Photone (iOS) or Lux Light Meter (Android) to estimate light levels.
🔁 Step 5: Add Reflective Surfaces (Optional)
Reflective materials help bounce light back onto your plants:
- Foil-covered cardboard
- White walls
- Small grow tent
- Mylar sheets
These improve efficiency, especially in winter.
❌ Common Mistakes to Avoid
- Leaving lights on 24/7
- Hanging lights too high
- Not adjusting height
- No airflow (risk of mould/fungus gnats)
- Overwatering under strong lights
📚 Bonus Tip: Stackable Indoor Grow Shelving
If space is tight, use a vertical shelving system:
- Metal shelving unit (e.g., IKEA Hyllis)
- LED strips such as Barrina T5 under each shelf
Great for herbs, lettuce, and microgreens.
🌿 Conclusion
With your grow lights now set up correctly, you’re ready to enjoy fresh herbs and vegetables any time of year — even during winter. A simple indoor setup can make a surprising difference to your daily harvest and your self-sufficiency goals.
If you’d like more neutral, expert-led information, the RHS website is an excellent resource. As the UK’s largest gardening charity, they offer trusted advice on a huge range of growing topics.
If you want to browse all our grow light guides and comparisons in one place, see our Grow Lights UK hub.
📎 Related Guides • Grow Light Distance Chart UK A practical reference for hanging heights and safe distances for bulbs, bars, and LED panels. • Best Indoor Grow Lights UK for Beginners Simple, plug-and-play grow lights that work well for herbs, seedlings, and small indoor setups. • Grow Lights UK Our complete guide to grow light types, setup basics, and choosing the right light for your space.
How do I set up grow lights indoors for beginners?
Start by choosing a stable location with a nearby plug socket. Place the lights 12–24 inches above plants (LED) or 6–12 inches (fluorescent), and use a timer for consistent light cycles.
How many hours a day should grow lights be on indoors?
Seedlings need 16–18 hours of light. Leafy greens and herbs grow well with 14–16 hours, while fruiting plants like chillies or tomatoes need around 12 hours once they flower.
Can I grow vegetables indoors with LED grow lights in the UK?
Yes. LED grow lights make it possible to grow herbs, lettuce, leafy greens, and even chillies or tomatoes indoors year-round in the UK.
Do I need a timer for indoor grow lights?
A timer is highly recommended. It ensures plants get consistent light cycles — for example, 16–18 hours for seedlings and 12–16 hours for mature plants.
What is the easiest way to set up grow lights indoors?
The easiest way to set up grow lights is to place them above your plants on a shelf or stand, keep them 12–24 inches away (for LEDs), and use a plug-in timer for consistent light cycles.
Do I need special equipment to set up grow lights at home?
No — you only need a light, something to hang or support it, and a timer. Many beginners simply use a shelf unit when learning how to set up grow lights for the first time.
How do I know if my grow light setup is strong enough?
A simple way to check is to look at your plants. If they look leggy or lean toward the light, your setup needs adjusting. This is very common when people first learn how to set up grow lights.