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.
It is a lovely specimen. We have articles on grow lights that should help. Cacti and succulents require high light and don't do as well under artificial lights as they would with direct sun. However, if you can summer them outdoors it will help. Read the articles below and choose a high light setup for your plant. I would suggest a vertical arrangement since your plant is tall.
https://extension.missouri.edu/publications/g6515
https://www.gardeningknowhow.com/houseplants/hpgen/fluorescent-lighting-for-indoor-gardening.htm
https://www.gardeningknowhow.com/houseplants/hpgen/led-grow-light-information.htm
Whats wrong? First year it was outside for summer, last year not. Does not get direct sunlight in house.
I suspect it is overwatered and lacking light. Since it was outside last summer, it got more light, and water evaporated more quickly. During the winter they need little to no water but high light. Try to find a sunnier place in the house where you can move it. Let it dry out completely between waterings. In case it is suffering from root rot, go ahead and repot it in fresh succulent mix.
Here is more on its care:
https://www.gardeningknowhow.com/ornamental/cacti-succulents/pencil-cactus/care-pencil-cactus.htm
rage more global growth? I have a pencil cactus now for the last three years. The main plant has not really grown much. However, the middle trunk shoots off long wispier branches. This is the only new growth. Is there a way to prune the other original branches to encourage growth as well?
Pencil cactus doesn't really need pruning. It will branch out on its own. If it becomes too large, however, you can cut it back, but be careful of the toxic sap it exudes. You can root any cuttings you take.
It may need more light, or if inside, turn it weekly so all sides get sun. They do put out little wispy "leaves" but those tend to disappear after a while.
Here is how to care for your pencil cactus:
https://www.gardeningknowhow.com/ornamental/cacti-succulents/pencil-cactus/care-pencil-cactus.htm
Cannot get all small dead Twigs up. Are they toxic when dead and brittle
It's the sap or latex that is irritating to the mouth and stomach and can cause vomiting. After extensive research, I couldn't find elaboration on whether the irritant exists after the plant is dead and brittle, but I would suspect the danger is greatly reduced. (However, I did read that you can still get poison ivy when the plant is dead.)
I would err on the side of caution and put soil, pebbles, or mulch on the area where the twigs fell and steer the puppy clear of the area.
https://www.aspca.org/pet-care/animal-poison-control/toxic-and-non-toxic-plants/pencil-cactus
Our pencil cactus is 10 feet tall and is leaning heavily to one side. The base of the trunk is curved and that is the problem. How do we remedy this? Do we stake it? It’s so heavy that we are worried it will topple over. It’s such a beautiful plant, we don’t want to lose it!! Thank you.
I suggest trimming and staking it. Do not trim it like a standard or it will fall over. When you trim, start from the bottom up, so the sap, which is toxic, doesn't leak down on you. Trim stems evenly back to their point of origin. Do not leave stubs. Also, always wear gloves when handling and/or trimming this plant. When you cut it, milky sap will run and some people are very allergic. Make sure it doesn't get near your face, i.e., eyes, nose, mouth. There are some YouTube videos on pruning pencil cactus you may want to check out. You can cut off some of the top as well and start new plants with the cuttings.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/pencil-cactus/care-pencil-cactus.htm
https://ucanr.edu/sites/PlantSafely/ToxicPlantList/Euphorbia_tirucalli/
Currently, the pencil plan its about 5 ft. tall and growing in house in a large container. It has gotten very dense and has no shape to it.
Be sure to wear gloves when pruning pencil cactus to avoid the toxic sap. These articles should help:
https://www.gardeningknowhow.com/ornamental/cacti-succulents/scgen/cactus-pruning-info.htm
https://www.gardeningknowhow.com/ornamental/cacti-succulents/pencil-cactus/care-pencil-cactus.htm