Neobuxbaumia polylopha

Botanical Name — Neobuxbaumia polylopha

Common Name — cone cactus, golden saguaro, golden spined saguaro, and wax cactus

Plant Family — Cactaceae

Background

Neobuxbaumia polylopha is a species of large columnar cacti, found almost exclusively in a small region in Guanajanto, Mexico. In recent decades this plant has been found distributed in southwestern parts of the United States. Where it is endemic it grows in canyons with limestone slopes. Its specific epithet, polylopha, translates to “many ribs”, and references the 10 to 30 ribs that can be counted on each segment. These large plants can reach tree-like stature, growing to heights over 15 meters in ideal conditions.

Growth Requirements

Sun

Neobuxbaumia polylopha prefer lots of sun, at least five hours of direct sun daily.
Indoors a south facing window is ideal. Outdoors, place them in a spot where they will get plenty of sun exposure. If you are growing this plant outdoors be sure to provide it with light shade to protect it from intense, peak afternoon sun.

Temperature/ Humidity

Mammillaria spinosissima do best in high temperatures and low humidity. Ideal temperatures range between 70 and 80 ºF. These plants should be brought indoors when nighttime temperatures fall below 50 ºF.

Water

Being native to a desert climate, these plants prefer to stay on the dry side. In the summer water them only when the soil has dried out entirely. Always err on the side of under watering. They are built to withstand drought, and overwatering is one of the quickest ways to kill them.
During the winter it’s safe to cut back on watering entirely. This will encourage flowering during the spring!

Soil/Roots

These plants require a gritty, sharply draining soil mix. Amend regular potting soil with sand or fine pumice up to 50% to improve drainage and soil texture.

Flowering

Neobuxbaumia polylopha typically blooms during the summer. These plants are nocturnal bloomers. This plant can produce many flowers at a time in small clusters near the tip of the plant. Flowers are colored deep red or vivid pink or magenta. Flowers give way to small fruits, which are edible to humans when ripe.

Fertilization

Fertilization of this plant is generally not necessary. If you want to refresh your soil or give your plant a boost during the growing season, you can feed it monthly with a fertilizer for cacti and succulents. Fertilize only during the spring and summer, when the plant is actively growing.

Propagation

These plants propagate easily from cuttings. Cleanly sever a stem section or an entire branch. Set the cutting in a shaded place to allow the wound to callous over for a few days before potting it into soil and placing it in a sunny location to grow.

Health

Diseases

These plants are not especially susceptible to pests or diseases. Keep an eye out for pests that commonly affect houseplants, such as scale and mealybugs. Also look out for any unusual spotting that may be a sign of an infection.
Treat infested plants with diluted neem oil. If plants are infected with a bacterial or fungal disease, prune away any affected parts of the plant.

Maintenance (pruning, legginess, repotting)

Little maintenance is required to keep these plants happy. The should only need to be repotted once every two to three years. When transplanting, select a pot that is at least two to three inches wider in diameter to give the plant plenty of room to grow.

Toxicity