Wednesday, January 16, 2013

Wilting Sansevierius - Causes and Cures

My Wilting Mother-in-Law Tongue Plant
Help I’m Wilting and I can’t get up….…this was the cry from my snake plant ( good luck plant, mother-in-law's-tongue,  devil's tongue, Sansevieria).   I have had this plant for several years. I had just pulled it inside from a glorious summer al fresco, and split it into two large pots.  It seemed fine for a few months. Then it started wilting, and a wilting houseplant is a cry for help. 

Sansevieria is a strong plant, it’s in office spaces and given to people who can kill just about anything else. So I was perplexed as to what was going on and consulted every source I could find on-line and a solution.  Here is what I learned:
1) Know what “healthy” looks like for your plant
2) Know what about your situation is unique. Take into consideration the environment that your plant is in (Potting soil, container size, lighting, heat, drafts.
3) Understand the causes of wilting for the plant in question
4) Experiment and learn to listen to what your plant is telling you – what other people tell you to do may not work for you.

A Healthy Sansevieria
There are many different varieties of Sansevieria. In a walk through the garden center and Garfield Park Conservatory I snapped several shots which are included here.  Almost all the plants display the characteristic tall and erect form. Snake plant leaves may be striped or marbled pattern, vibrant to dull green, or yellow and white.  I think I even saw a chartreuse one once.  The color of the plant may impact the amount of light it needs. I have some placed against interior north walls with very little indirect light. I have others in east facing windows with plenty of sun.  I've had snake plants thrive in areas which offer full sun to dense shade; most grow best in persistent indirect light.   I plant most in cactus mix but occasionally will use regular potting soil. Once I even planted in a container in regular garden soil (not advised.)  The latter was a demonstration of what not to do – but that darn Sansevieria survived for over two years in rock hard soil.  In the conservatory we had one Sansevieria that was placed under a hole in the roof, and it was constantly water logged for several months. It was just fine.  Thus it’s safe to say snake plants will survive poor soil conditions, at least for a period of time. However if optimum soil and light and water conditions do not exist, in time, you may experience pests, root rot, or the dreaded wilt.
In the photographs below are several different types of Sansevieria. The photos were taken at Chicago's Garfield Park Conservatory Desert Room. 
Mother-In Law, Baseball, Moonshine, Variegated, and Longhorn Sansevieria (Snake Plants)

My Unique Situation

Here is where I admit all the things that I had done with these sansevieria that were not up to par.  First off I had them outside in all kinds of rain – that seemed fine, and at the end of the summer I decided to divide them when I brought them back inside.   This was the first problem – I replanted them to shallow and without  sufficient support considering the mature height of these plants.  There was an immediate hit to their health – which I chalked up to being re-potted   I later tried to add some support and tied them up, but a large number of leaves were already wilting and folded off to the side.

During transplantation I was able to see that the roots were in solid condition and there were wet areas of neither dying plant tissue nor fungal growths.  There were also not any insects or infestations. I had good soil mix and balance of fertilizer – so these were on the plus side.

Secondly,  I did not use the right container. The pot for the Sansevieria is way too large for the number of plants it holds. It is also much too deep. However, for the room it is in, I like the larger base pot – which also helps to keep it from tipping over from the dog. Plus I just loved the blue. This was an aesthetic decision, not one for the plants health.  With an over-sized container the plant might get too much water and have root rot – or not enough if the roots are shallow (as with some succulents.)

Lastly with respect to light – they are placed in a west facing window with a few good hours of direct sunlight each (non-gray) day. Good filtered light.  There was no discoloration of the leaves, e.g. yellowing, which would indicate excessive sunlight. So I felt comfortable with the lighting situation on this pair of containers.  Note that the containers are in the bay window, directly above the heat vent.

The causes of Sansevieria Wilting

My research says thee possible reasons for wilting leaves on a Sansevieria plant are:

1) Over or under watering
2) Improper lighting (too little makes them flip over)
3) Infestation (such as thrips)

My Experimentation

I quickly rules out lighting and thrips- and moved onto experimenting with watering.  I found it very interesting that both over-watering and under-watering could make the leaves droop, bend, wilt or begin to look wrinkly. 

OVER-WATERING: Over-watering is the most common problem for houseplants, so why not develop root rot easily, especially in containers. If you  suspected root rot you can check to see if the soil is moist or wet on the surface and down a few inches. Also pull gently on one of the outer leaves and it comes off easily at the soil level, and the root stinks and is mushy; then sorry, it's got root rot. Best solution here is to throw the rotten parts away – and repot what remains in the new soil.

Up until this point I had been watering the plants every other day when they were outside, and when they came inside I was watering them every third or fourth day. To which my friends cried “What? That’s too much!” I did not have root rot, but I cut it back to the once a week or less per recommendations from garden centers and websites. This went on for several months – and I did not see any improvement in the plants. Upon checking the soil with my hands, I knew that it was dry for several inches into the pot. This convinced me that less water was not the issue.

UNDER-WATERING - Then I realized that several factors were dictating that my Sansevieria needed more water than usual.  First off the pots are too big, and the soil mix promotes drainage – so the water quickly hits the bottom and doesn't stick around much for the plants. Secondly, the containers are right by the heat vent which will accelerate the need for water. Lastly they are in a good light area, which could also mean more water.

So, I went the other way and started watering every four days, and then every two days. Watering means 3-4 cups of water each time, not a complete soaking.

While there are still some bent leaves, there is not solid new growth and vibrant color back in the plants. I’m so happy that they lasted through all these trials and told me when they were happy. I regularly check the soil to a depth of 2-4” to make sure I’m not watering too much, and I apply cactus fertilizer every other week. (If the tips of the leaves turn brown – that’s too much fertilizer) I also rotate the plants and make sure to prop up some of the leaves against the glass – they top 3 ft tall, so I think they have earned a little support ;)

Like many succulents, Sansevieria grow very slowly – it may take time to know if something is wrong or if you fixed it. You may need to play with light exposure and watering to get your plant healthy.

So my parting shot for today is of the Zulu Sansevieria. I love how wide and tall the leaves are. There is just a hint of red along the edges of the leaves. In the pot on the right, I can just hear it asking me to repot it and take part home :)
Zulu Sansevieria
All the best;

Teresa Marie