Do you need a grow light in Brisbane? Usually not
Grow lights are everywhere online, and some of the marketing would have you believe you can't grow basil without one. In South-East Queensland, most people with a balcony or a sunny window don't need one at all. Here's how to tell.
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We have a lot of light
Brisbane sits at about 27° south and gets plenty of sunshine through the year. Even in the middle of winter, days are around 10.5 hours long and often clear. For most edible herbs and vegetables, a spot that gets 4–6 hours of direct sun is plenty, and many balconies here get more than that.
If your plants outdoors are struggling, the usual culprits are water, pot size or potting mix, not light. Fix those first before spending money on a lamp.
When a grow light does make sense
- Growing indoors, away from windows. A kitchen bench or shelf a few metres from the nearest window gets far less light than it seems to the human eye.
- A south-facing, shaded balcony. In the southern hemisphere, south-facing spots get the least direct sun, especially in winter when the sun sits low in the northern sky.
- Balconies shaded by other buildings, or deep covered balconies where the sun never reaches the back.
- Starting seedlings indoors, where weak light makes them tall, pale and floppy ("leggy"). A seed tray with a humidity dome under a small light gives them a steady start.
Signs your plants aren't getting enough light
- Long, stretched stems with big gaps between leaves.
- Plants leaning hard towards the window.
- Pale, small new leaves.
- Herbs that survive but never really grow, even with good watering and feeding.
Try moving the plant to a brighter spot first. Rotate indoor pots a quarter turn every few days so they grow evenly.
If you do buy one: keep it simple
For a shelf of herbs you don't need a large "professional" hydroponic panel. A modest full-spectrum LED light is enough. What to look for:
- LED, not old-style fluorescent or incandescent. LEDs use less power and run cooler.
- Full spectrum or "white" light. The purple/pink lights work, but white light is much nicer to live with and makes it easier to spot plant problems.
- A built-in timer. Around 12–14 hours a day is a common starting point for leafy herbs.
- Adjustable height or a clip-on arm, so you can keep it at the distance the manufacturer recommends. Too far away and it does little.
- The Australian RCM mark on mains-powered products, which indicates it's intended to meet Australian electrical safety requirements.
A clip-on full-spectrum LED grow light with a timer is plenty for a shelf of herbs. If the light you like has no timer, add a cheap plug-in timer switch so it runs the same hours every day.
The bottom line
If you have a sunny balcony or a bright north- or east-facing window, save your money and put it towards a better pot and potting mix. If you're growing indoors in a dim spot, a small LED light can make a real difference. Just don't overbuy.