The Brain Cactus: Stenocactus multicostatus

🌿PLANT OF THE MONTH🌿
Stenocactus multicostatus
The Brain Cactus

There are plants that are beautiful because of their flowers, plants that are beautiful because of their foliage, and then there are plants that are simply fascinating to look at. Stenocactus multicostatus falls firmly into the last category.

Also commonly called the brain cactus, this small Mexican cactus is remarkable for its extraordinary number of tightly packed, undulating ribs. The result is a plant that looks almost sculpted, with layer upon layer of pleats covering its rounded body.

WHERE IT COMES FROM

Stenocactus multicostatus is native to northeastern Mexico, where it occurs in desert and dry shrubland environments. The species is currently accepted by the Royal Botanic Gardens, Kew, although it has accumulated a surprisingly long list of botanical names over its history.

Lee's Note:

I walk through Lowe's two or three times a week. I know, that probably sounds a little crazy, but their sale plants can be incredible if you know what to look for.

I usually walk right past the cactus and succulent section, but this particular brain cactus caught my eye. It was already interesting enough to make me stop, and when I saw it was half off, I didn't think twice. I snatched it up.

It has since found a home in my cactus collection, where its unusual, tightly pleated form really stands out among the other plants. Now I'm just waiting for it to fill out its pot and start sending off shoots. That's when I think it's really going to become something special.

HOW IT GROWS

This is a small, slow-growing cactus with a rounded to somewhat cylindrical form. Its defining characteristic is its unusually high number of narrow, wavy ribs. The ribs give the plant a heavily pleated appearance and are responsible for the common name "brain cactus."

Unlike many landscape plants that are grown primarily for their size or flowers, this is a plant where the structure is the show.

The genus Stenocactus consists of small, heavily ribbed Mexican cacti, and S. multicostatus is one of its most distinctive members.

SIZE

Expect a relatively small plant, generally remaining in the range of a small container specimen rather than becoming a large landscape cactus. Some horticultural references report mature plants reaching approximately 8 to 20 cm in diameter, depending on the form and growing conditions.

That compact size makes it particularly useful for containers, cactus collections, rock gardens and other places where a plant's form can be appreciated up close.

FLOWERS

The flowers emerge from the crown of the plant and appear during the warmer growing period. They are relatively large compared with the body of the cactus and provide a striking contrast to its heavily ribbed surface.

Flowers are generally white to pale pink or purplish, often with darker central markings.

The flowers are almost a bonus. The real attraction of this plant is the bizarre architectural structure of the body itself.

LIGHT 

Give it bright light and plenty of sun, while protecting it from excessive heat and intense afternoon exposure if necessary.

In cultivation, the goal is strong enough light to maintain compact growth without subjecting the plant to conditions that cause scorching or excessive heat stress.

SOIL 

Drainage is critical.

Use a very well-drained cactus or succulent mix, preferably with a substantial mineral component. The pot should drain freely and should never remain saturated.

This is a plant adapted to dry environments, and its roots need access to oxygen as much as they need water.

WATER 

The basic rule is simple:

Water thoroughly, then let the soil dry before watering again.

During active growth, it can receive regular irrigation as long as the growing medium drains rapidly and is allowed to dry between waterings. During winter or periods of cool weather, watering should be greatly reduced.

Overwatering is a much greater threat than underwatering. The combination of wet soil and cool conditions can lead to root and stem rot.

PROPAGATION

Seed is the primary method of propagation.

Seeds can be started in a well-drained growing medium under warm conditions. Some plants may also produce offsets or shoots that can potentially be separated and grown independently, but seed propagation is the standard approach.

For the home gardener, this is one of those plants where propagation is more of a long-term horticultural project than a quick way to make dozens of new plants.

THE HORTICULTURIST'S TAKE

Horticulturist's Rating: ★★★★★ 5/5

This is a five-star plant in my book. It's unusual without being fussy, stays relatively small, has incredible structure even when it's not flowering, and makes a great conversation piece. If you come across one at a reasonable price, I'd have a hard time telling you to leave it behind.