The clocks have gone back, and it's dark before dinner. If you grow at home with a hydroponic garden, you've probably noticed the change: lettuces take longer to fill out and herbs start to stretch. Your system is fine — your plants are simply getting less light.
Here's why light matters most at this time of year, and how a simple LED setup can keep your garden productive right through to spring.
Why light is the limiting factor in winter
In hydroponics, water and nutrients reach the roots in a controlled way. The one thing you can't control is the sun. As days get shorter and greyer, plants receive less light for photosynthesis — and no amount of nutrients can make up for that.
As we explain in What can I grow in Aeroponics?, what grows well starts with the light, the climate conditions, the quality of seeds and seedlings, and ongoing maintenance. In winter, light is usually the first of those to fall short.
Signs your plants need more light
- Slow growth, even though the nutrient solution is in good shape;
- Leggy plants: long, thin stems with widely spaced leaves, reaching towards the window;
- Paler leaves and lettuce heads that never quite close up.
Choosing the right LED grow light
You don't need commercial equipment for a home garden. The key is matching the light spectrum to what you're growing.
LED growth bars (6500 K) for leafy greens and herbs
The PLED 42 W 6500 K LED Bar – Growth is a 95 cm Pure Factory LED bar that can hang vertically or horizontally. Its spectrum is tuned to plant growth, and it's ideal for the plants' first weeks (seedlings or cuttings). For smaller spaces there's also the PLED 26 W 6500 K LED Bar – Growth.
Lettuce, rocket, parsley and coriander spend practically their whole life in the growth stage, so a growth-spectrum bar is a natural fit.
Full-spectrum LEDs for bigger setups
Growing fruiting crops or running a larger garden? A full-spectrum LED such as the Full Spectrum LED Zeus Pro 465 W covers every stage of the plant's life.
Setting up your LED light: practical tips
- Hang the light above or beside your plants so it covers the channels evenly. On a vertical garden, a bar hung vertically alongside the frame often works best.
- Put it on a timer. Switching the light on and off at the same time every day is as important as the amount of light. The 24-Hour Analogue Timer switches electrical devices on and off and can be set in 15-minute intervals.
- Supplement, don't replace. If your garden sits by a window or on a balcony, make the most of daylight and use the LED to extend the plants' "day" into the evening.
- Watch your plants. If they're still stretching, move the light closer or add a second bar.
Keep the nutrient solution in good shape
Light and temperature go hand in hand in winter: if the reservoir gets too cold, plants slow down even under good light, so keep your garden somewhere sheltered from the cold.
Your plants also drink the nutrient solution every day, so the level in the reservoir drops. Simply top it up with water and nutrients to keep the system running. For leafy crops, the Nutrient Kit for Leafy Greens – 1 to 1000 L provides the essential macro and micronutrients, with dilution instructions included.
What to grow under LED light this winter
With the right light, winter is a great season for leafy greens and herbs:
- Lettuce — try Red Batavia Lettuce (pelleted seeds) for colour in your salads;
- Lamb's lettuce, a classic winter salad green — see Lamb's Lettuce Pulsar seeds;
- Rocket, parsley, coriander and watercress, which all do well in GroHo gardens.
No garden yet? Winter is a great time to start
An indoor hydroponic garden with an LED light means fresh greens even in the darkest months. The Fixed Vertical Garden – 40 plants is just 20 cm wide and fits against a kitchen wall. It's a turnkey system with channels, submersible pump, timer, reservoir and a nutrient kit included. Prefer a horizontal layout? Take a look at the Horizontal Garden – 40 plants.
Quick recap
- Short days make light the main limiting factor for winter growing;
- 6500 K LED growth bars suit leafy greens and herbs;
- A timer keeps the light schedule consistent;
- Keep the reservoir sheltered and top up the nutrient solution as plants use it.
Not sure which light fits your setup? Get in touch — we're happy to help.
Happy growing!
