LED grow light red blue

Autumn is fast approaching, as the light is lessening and the nights are getting colder it’s time to take extra care of our tropical plants. In practice that means one thing; tropical and mediterranean plants need to move either inside the house or in a heated greenhouse. Temperatures in the Netherlands can drop far below zero in the winter time. So all tender plants must move inside way before that. Currently night temperatures get below 10°C sometimes so it’s time for the great plant migration!

I’m growing some tropical plants including; mango, avocado, pineapple, cherimoya, ginger, lemongrass, curcuma, papaya and coffee and some mediterranean plants like olive and citrus. All these plants have to move inside the house or face certain death. The plants continue to grow and I continue to buy plants ¯\_(ツ)_/¯ so the struggle to fit everything in the house increases every autumn.

The increase in plants and plant size also means not every plant can get a front row seat by the window. So we need to supply the plants in darker places with additional lighting. It important to note that tropical plants don’t have seasons like we up north do. Tropical plants don’t know a autumn, winter, summer and spring. Mostly they have a dry and a wet season. The amount of light hardly changes through the year, since the plants grow around the equator.


Luckily there is a whole market of grow-lights available! There are many options available including often used High Intensity Discharge (HID) lights or High-Pressure Sodium (HPS) lights. I’ve found these lights too daunting to begin with so I only experimented with LED’s. LED’s are very energy efficient and (contrary to HID and HPS) can be plugged directly into a standard electrical socket.

LED grow lights comparison

Red + Blue grow lights

There are many different types of growing LED’s but they can roughly be divided into two categories. Red + Blue light or white light. I started with the Red + Blue lights, the ratio red and blue changes per manufacturer but the effect is the same, a reddish purple light. The same lights are used commercially. Plants don’t use all colors of the light spectrum in the same way. Blue’s and red’s are used most by plants and they grow normally when exposed to only these two colors. I’ve found these lights work perfect for my plants, but the light is quite unpleasant for the eyes. You wouldn’t want to use these lights in a room where you’ll be spending much time.


White grow lights

White grow LED’s provide a full spectrum light, they emit similar amounts of red and blue light but with the added green light so as to appear white. These lights are almost like ‘normal’ lights and can be used in the living room or wherever you want to over-winter your plants. Recently IKEA has entered the in-house-gardening party with their own grow lights. These Växer LED’s are available in LED strips or as lightbulbs. I’ve used the lightbulbs last winter and the plants survived perfectly well.


If you start using grow-lights it is a good idea to also use a timer to switch the lights on and off. Plants like a good routine and a timer is an easy way to provided that. Don’t be tempted to leave the lights on 24/7 to encourage growth; plants need the dark too. Overall a 12h light period seems to work well, but still research the light needs of your plants as the can greatly differ.