Sansevieria (2007)

PhotoBy Susan Carpentier (March 2007)

The name Sansevieria originates from that of Raimond de Sangro, the prince of Sanseviero. He was a faithful patron of horticulture in Italy during the 18th century.

An article from the University of California Botanical Garden in Berkley states “the genus of Sansevieria has wandered from family to family … starting out as, then Agavaceae and finally newly showing up in Dracaeaceae.” It is listed in the HSCS show schedule under Agavaceae. Most sansevierias are native to old world Africa. Others are from the Arabian Peninsula, Comoro Island, India, Sri Lanka and Myanmar.

The International Sansevieria Society website shares that most spread their growth through underground rhizomes. These are very strong and can split a plastic pot or shatter a clay one. In open ground, many send new shoots downward and then turn upwards, ensuring that new growth is not too far from the mother. When sansevierias are confined to a pot, the new growth may push the whole plant and soil out of the pot or simply break the pot apart. The only way to avoid this action is to plant in deeper pots.

As my sansevierias get bigger, I plant them in plastic pots, which bend and are not as heavy. Before I knew much about sansevierias, I planted a small one in a very large pot, thinking I would prolong the time between repotting. I was wrong – the sansevieria went wild with new growth.

Leaf shapes can be any of the following: tight rosettes; broad with soft tips; narrow ending in a point; elongated, thickly cylindrical points reaching several feet into the air; spoon shape; double columns like stacks of cow horns; like a baseball bat sawed down the middle; very thick leaves that resemble a miniature agave and flat leaves of great thickness.

The colors of leaves can be dark green (almost black), green with yellow edging, pale green, light green, light yellow, silver frost, pink and gray with hardly any green, and white-striped.

Sansevieria blooms can be white, pale green, purple, pink or red flowers that look like fireworks in the sky on a Fourth of July evening. Their scent can be very powerful and is often strongest after dark. I have to remove plants from my living area because of the strong scent.

Growing Mixture
I have used a growing mixture of one-third growing mix, one-third pea gravel and one-third small pine bark. It was too much work to find or break up the bark into small pieces, but after some overwhelming research that found most growers’ mixes had peat in them, I found making my own was just as good.

At first I wanted a growing mix called Black Gold, but found it is only sold on the U.S. West Coast. So I decided to use organic dirt or compost mixed with coir, turface or pea gravel. I had a small amount of diatomaceous earth the size of nickels from my husband and used it in a few plants. I would like to use the diatomaceous earth for all my plants.

The green sansevierias can grow in almost any mixture, but the variegated sansevierias are harder to keep alive and susceptible to rot due to overwatering. While researching this article, I learned that author Juan Chahinian uses a soilless mixture for the variegated sansevierias. I believe it is the same mixture Mike Hellmann spoke about at the February HSCS meeting.

Summer Season
When I take my plants out for the summer, I put them in total shade for at least nine days. While outside, my sansevierias get morning sun or filtered light. Those on the porch receive full afternoon sun, so I must use a shade cloth.  Sansevierias do not do their best in strong direct sun.

During the summer, I try to water in the morning and on sunny days. I have lost variegated sansevierias due to too much water in the winter and summer. Sansevierias need warmth and quick-draining soil. They cannot stand to have soggy roots, especially in the cool weather.

In Florida, sansevierias are used for landscaping. Experiments discovered that varying ratios of nitrogen and potassium fertilizer did increase growth. But high rates of nitrogen made plants susceptible to chilling injury when temperatures dropped to 34-46 degrees F. In Missouri, our plants do not stay outside all year, so this wouldn’t be an issue. Too much nitrogen also made leaves long and weak.

When I repotted some of my plants last summer, I added some earthworm castings to my growing mix. I saw some new healthy growth. I do not add this to my cactus-growing mix. I also use time-released (six-month) fertilizer.

Winter Season
I do not have a greenhouse. I have a plant stand in my basement with lights. I also have tables in my living and dining rooms by the windows. I have a fan in the basement for the plants and make sure it stays on after watering.

I also try to keep the ceiling fan on upstairs at all times and make sure it is on after watering. Remember that sansevierias do not like to sit in water, especially when it is cold. I have gotten brown spot, which I believe could be a fungus caused by poor air circulation.

Next winter my entire colelction of variegated sansevierias will go in the basement, where I have more control of the fan. Upstairs, I will buy smaller fans to help circulate the air. These won’t bother the family as much.

Sources: – “The Subtle Sansevieria” – Jeanette Atkinson
Los Angeles Times – “Bold Beauty” – Lili Singer
International Sansevieria Society
University of California Botanical Garden – “Mother-in-Law Tongues and Other Sansevieria” – Fred Dortort – “Sansevieria – The Snake Plant” – Connie Krochmal
The Sansevieria Trifasciata/Varieties – Juan Chahinian