Pencil Cactus Care Guide
The pencil cactus, or Euphorbia tirucalli – also commonly called milk bush due to its thick, white sap – is native to semi-arid tropical regions of Africa and India. As an indoor plant it requires minimal attention, though care must be taken when maintaining this plant. Some people experience a rash when coming into contact with the sap, and this plant is toxic to animals, so take care when choosing its location. The pencil cactus, which can grow up to 30 feet in the wild and well over 6 feet indoors, is not a true cactus but a stem succulent. Stem succulents photosynthesize in their stems, not their leaves. The small leaves that appear on the end of the pencil cactus’ new growth are inconsequential to the plant’s health and often fall away quickly. As these plants evolved in dry climates with lots of sun, keep your pencil cactus in a bright location for maximum growth. The pencil cactus can survive in lower light areas but will not put on significant growth over time without bright light.
Stem succulents photosynthesize in their stems, not their leaves.
Your pencil cactus only needs occasional watering. Cacti and succulents store water in their flesh and can be easily overwatered. With such plants it is better to err on the side of too dry rather than too moist. A dehydrated cactus or succulent has the potential to recover, but a rotting plant will generally continue to rot.
Euphorbia issues are, more often than not, related to watering. If the skin becomes less opaque (the skin may possibly appear slightly bruised), soft and wrinkled the plant is receiving too much water. Stop watering your plant and allow the soil to dry thoroughly and remove damaged tissue. On the other hand, if the plant becomes brittle, shriveled and dull in color it is in need of more water. Thoroughly water the plant slowly saturating the soil with 1-2 liters of water. You should notice the plant become more fleshy in a day or so. Let the plant be. Parts of the plant may continue to brown and get ready to shed, as long as the succulent has regained some of its color and volume it will recover.
Use caution when handling Euphorbia plants. Though the pencil cactus is a simple and easy plant from which to take cuttings and propagate, the milky white sap can cause moderate to severe allergic reactions, especially in those with latex sensitivities. Take care when handling your pencil cactus, wear gloves if possible and be sure to wash your hands thoroughly.
Self Watering Container Instructions
For the first month, top water only. That means you will be watering the soil directly, not by filling the reservoir. This ensures that the roots reach down far enough to be able to wick the moisture from the reservoir.
After the first month, test the reservoir to see if the plant begins drinking. Fill the reservoir through the channel until the red indicator reached the max line. If over the next few days the indicator begins to lower, that means your plant has successfully begun to drink from the reservoir. If the red indicator does not lower then continue top watering for another few weeks. Only when the reservoir is empty and the top few inches of soil is completely dry do we recommend refilling the reservoir. Since the Pencil Cactus prefers longer period of drought, you can even wait 10-14 after the red indicator has reached the minimum line before you refill the reservoir.