If you’re wondering how to set up grow lights indoors in the UK, this beginner-friendly guide will walk you through everything you need to get started — from choosing lights to growing fresh herbs and vegetables, even in winter.
Not quite what you’re looking for? Take a look at our Grow Lights UK – Complete Resource Hub for a full overview of light types, setup tips, and running costs.
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What You’ll Need
Not every setup needs all of these, but here’s a quick checklist of what you will need to set up grow lights indoors:
- A grow light (LED panel, strip, or bulb)
- Something to hang or stand it on
– e.g. adjustable tripod stand, rope hangers or a shelf unit - A plug-in timer
– e.g. simple mechanical timer or smart digital plug - Tape measure (for height setup)
- Optional: reflective surface, grow tent, light meter app
Step 1: Choose the Right Spot
You don’t need a fancy grow tent — but the right location helps a lot.
- Choose somewhere with a stable temperature, not freezing cold or baking hot.
- Avoid rooms with too much natural light glare or cold draughts.
- You’ll need a nearby plug socket and preferably some airflow (a cracked window or fan is plenty).
Avoid growing near radiators or in damp spaces like uninsulated sheds.
Step 2: How to Set Up Grow Lights Indoors at the Right Height
How high should you hang your grow light? It depends on the type and whether you are setting up led grow lights or fluorescent lights.
- LEDs: start around 12–24 inches (30–60 cm) above plants
- Fluorescent lights: can sit much closer — around 6–12 inches
Each brand varies, so check the box or manual if possible. You can use ratchet hangers to make adjusting easier — these are cheap and reliable.
Too far = leggy, weak plants
Too close = scorched leaves or bleaching
The hand test works well: hold your hand where your plant will be. If it’s too hot for your hand, it’s too hot for seedlings.
Step 3: Add a Timer (Set and Forget)
When setting up indoor grow lights for herbs and vegetables consider getting a timer. This way you don’t have to remember to keep turning the lights on and off, which could be bad for the plants and also your electricity bills.
- For seedlings: 16–18 hours light / 6–8 hours dark
- For leafy greens and herbs: 14–16 hours light
- For fruiting plants (like chillies or tomatoes): 12 hours on / 12 off once they start flowering
Plug-in timers cost a few quid and are totally worth it. I use this mechanical plug in timer, but smart plugs work too if you prefer controlling things from your phone. Here is an excellent multi block smart power strip which will allow you to set up different timings for different plants if required. Alternatively you can use individual smart plugs.
Step 4: Adjust as You Grow
Plants grow. That means your lights need to move too.
- Raise the lights gradually as plants get taller
- Rotate trays or pots every few days for even coverage
- Watch for signs:
– Leggy, pale plants = too little light
– Crispy or curled leaves = too much
Adjusting your setup regularly is one of the keys to success when learning how to set up grow lights indoors effectively.
If you’re curious about light levels, free phone apps like Photone (iOS) or Lux Light Meter (Android) can help you roughly gauge intensity at canopy level.
Step 5: Reflective Hacks (Optional)
If your grow setup is in a dark corner, you can reflect light back onto your plants using:
- Foil-covered cardboard
- White walls or surfaces
- Or even a small indoor grow tent
These reflective tricks make any indoor grow light setup more efficient, especially during the darker months.
Common Mistakes to Avoid
- Running lights 24/7 – plants need darkness to rest
- Hanging the light too high – you’ll get tall, floppy seedlings
- Not adjusting the height as plants grow
- No airflow – this can lead to mould or fungus gnats
Bonus: Stack It Up
If you’re looking for grow light systems for beginners that are simple to set up and are short on space, consider using an adjustable shelving unit with strip lights such as the Barrina T5 Grow Lights on each tier. IKEA’s Hyllis works well, or check out stackable metal grow racks.
Conclusion
Now that you know how to set up grow lights indoors, you’re ready to grow fresh herbs and vegetables all year round. If you haven’t chosen your light yet, check out my Best Indoor Grow Lights for UK Beginners (2025 Guide).
Want to expand your harvest? You might also enjoy my guide on How to Grow Vegetables Indoors in Buckets, which pairs perfectly with a simple grow light system.
With the right setup, you can enjoy reliable indoor gardening, cut down on supermarket trips, and eat home-grown food no matter the season.
Looking for more self-sufficiency and gardening guides? Visit HomeGrower to explore all our latest indoor and outdoor growing tips.
Coming soon: I’ll be posting more indoor grow tutorials and seasonal tips — so feel free to bookmark or check back!
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.