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Pencil Cactus

Q.Which Type Of Plant Growing Light Bulb Should I Buy For My Pencil Plant And At What Strength?

Zone Edmonton, Canada Growing zone 3b T6 | glynisdorey added on February 16, 2021 | Answered

I have had my 5-6 foot pencil plant for 20 years in a sunny house, Edmonton, Canada (cold winters) and it grew non-stop. However, now I am living in a north facing apartment with zero sun. I keep it on the patio during the summer which helps, but winter light inside is limited. The top side close to the window grows its little flowers/leaves However, the inside is doing nothing. Now I realise that I make it survive with a plant growth light bulb. Please help. I want to get it right. I bought the plant while living in the Ukraine, then brought it to Canada. Excited when I saw it in South Africa.

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Certified GKH Gardening Expert
Answered on February 16, 2021

This won't require much light to stay alive during the winter. It will require more light, should you decide to keep the trailing growth. If you decide to trim it, then you can get away with less light/less penetration depth.

A T5 panel of at least 100 watts will be plenty. You could go LED, as well, but make sure that it is not, simply, a red/blue spectrum. They need a full spectrum. Personally, I use Ceramic Metal Halide (CMH) lamps. They come in a, standard, 315 watt bulb and will light anywhere from a 4x4 foot area, to 6x6 foot area, depending on the light requirements of the plants. You can fit quite a few plants in this space.

If you just want to light this plant, alone, you won't need more than 100 watts.

Here is an article that will help you with the care of these plants:


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