Red-Green Pencil Cacti Plants
pencil cactus 1
(Image credit: Katharina13)

The pencil cactus plant is in the Euphorbia family of succulents. Another common name for the plant is Milkbush due to the cloudy sap it releases when injured. Be cautious when caring for a pencil cactus; the sap is toxic and may cause problems in some people. The pencil cactus needs high levels of light and moderately low moisture. It is an excellent houseplant and provides an interesting silhouette. Let's learn how to grow pencil cactus in your home.

Information on the Pencil Cactus Plant

The pencil cactus is a large plant native to Africa and India. The plant is ideal for sunny warm spots indoors or greenhouse growing. Care of pencil cactus is minimal. Euphorbia tirucalli, or pencil cactus, is a tropical plant that may become 30 feet (9 m.) tall in habitat. The stems are slender and slightly toothed with no obvious foliage. The branches are the diameter of a pencil, which give rise to the name. The new growth on the ends may be tinged pink and have tiny leaves which disappear as the branch matures.

How to Care for a Pencil Cactus

A pencil cactus needs very little care and can even be neglected if it's planted and situated correctly. The soil must be slightly gritty and well draining. The container to use could be an unglazed pot which will allow excess moisture to evaporate. Euphorbia plants are quite adapted to limited fertility environments, and care of pencil cactus requires only one fertilization in spring. Full sun and temperatures of at least 65 F. (18 C.) or warmer are necessary when learning how to care for a pencil cactus. Pencil cactus is easy to grow. It will need water approximately every two to three weeks in summer but no water in winter. Allow the plant to dry out between irrigations. Care must be taken when caring for a pencil cactus to avoid the sap. Even eye protection is necessary because the pencil cactus plant produces a toxin that can cause an anaphylactic reaction. In most cases it can be cleared up with antihistamine but occasionally more severe reactions occur and are difficult to clear.

Care of Pencil Cactus Cuttings

Pencil cactus is very easy to propagate with cuttings. Great care must be taken when harvesting and planting these to avoid the sap, but the cuttings will root readily. You will need small pots, a soilless medium to prevent rot and pathogens and a misting bottle. Take cuttings with a sterile razor blade and let them dry for two days to form a callus. Insert the cuttings into the medium at least an inch (2.5 cm.) deep and mist. Caring for a pencil cactus cutting requires low light and slightly more moisture than fully established plants. Once new growth commences, gradually introduce the plant to higher light and reduce watering. The cactus will hit your ceiling in just a few years, so don't be afraid to prune it and use the cuttings to make new pencil cactus plants.

Bonnie L. Grant

Bonnie Grant is a professional landscaper with a Certification in Urban Gardening. She has been gardening and writing for 15 years. A former professional chef, she has a passion for edible landscaping.