All About Sansevieria

The Sansevieria group makes up some of my favorite houseplants. Scientists recently placed them in the genus Dracaena, but its former scientific name seems to also be one of its common names. I will continue to refer to it as Sansevieria in this article to avoid confusion. In the future, you will most likely see the plant tags that come with plants offered for sale finally catch up with this change in the scientific community. This plant has many common names including “snake plant” and my personal favorite “mother-in-law’s tongue”.  Like many varieties of houseplant, there are some staples that have been around for decades, some newer species that have come to market, and some really interesting cultivars or hybrids of all of them. 

A tall variety of Sansevieria trifasciata with gold edges. Photo by mrl2024.

These plants have a rhizome, and the leaves grow from the base of your pot. They are very prolific when they like their environment. In fact, they tend to break the pots they are in, so I would recommend using plastic pots, which their growth will eventually deform. If you want to use a clay or ceramic pot, I suggest putting them in a slightly smaller plastic pot, then putting that in the clay pot. You can hide the gap between the two pots with Spanish moss. Being native to Africa, they cannot tolerate cold temperatures. Typical household temperatures work well, but avoid anything below 55 degrees F. If kept too cold, they will die and rot from the base up. By the time you notice there is a problem, it is too late to do anything about it. Another thing that is nice for the plant collector is that their upright growth habit allows the grower to have many varieties in a small space.

Overwatering is the quickest way to kill any houseplant, but especially so with these. In the winter, you probably only want to water once a month, and sparingly at that. Do not let them get soggy or this otherwise hardy plant will rot. In the warmer months when the plant is actively growing, allow the soil to dry between waterings, but then water more liberally. Some growers will add extra perlite to the mix to aid in drainage. I have not had trouble keeping them in a standard mix, but you certainly need to be careful with watering. Choose the mix that will work best for your plant hydration habits. These plants have the reputation of being a low light plant, which they certainly can handle. Sometimes, however, people place them in the darkest corner of a room where they hang on for a few months, but then eventually run out of stored resources and die. Remember they do need some light to photosynthesize so bright indirect light is best. The other problem I have seen is their unique, flat leaves can become covered in dust. Either dust them manually, use a blower, or take them outside in warm weather and hose them off. A damp cloth run gently over the leaves is probably the easiest method, but becomes more difficult and time consuming with a rather large collection.    

Sansevieria trifasciata ‘Golden Hahnii’ before (top) and after (bottom) division and repotting. Here, each baby plant got its own pot. Photo by mrl2024.

All varieties of Sansevieria are fairly easy to propagate. If you want more plants quicker, you can take leaf cuttings. You either dip in rooting hormone and replant, or you can place the cuttings in water to take root (change the water daily for best results). You must be careful with the orientation, as you want to plant the bottom side of the cutting into the soil, not the top, which will fail to root. It is easy to get confused and forget which end is up. Some people put a mark on the top or bottom, others cut in such a way as to indicate the bottom. It really doesn’t matter which method you choose, if any, as long as the cuttings are oriented properly at planting time.  There is one big problem with using cuttings – the babies will look like the standard green variety, and not have any of the nice golden edges, so be careful with this method. I also don’t like doing this as it, in my opinion, just looks unsightly. The remaining stub on the parent plant looks awful. If I was to do this, I would recommend cutting near the base of the plant by the soil surface. The cut leaf will not regrow, and instead just will look damaged. In the new pot where the cutting was placed, you still have to look at the cutting as it does not grow. It is not until the baby plants growing from the base are big enough that you can separate it from this actual cutting piece. 

My favorite way to propagate these plants is to let them grow, and then divide them during repotting. You simply pull the plant out of the pot and divide the rhizomes up so that each plant is separate, or in small clumps. This does require the cutting or breaking of the rhizomes, but this will not hurt the plant in the long run. This method produces the best-looking plants in my opinion. Even if you just have one plant per pot, they still look nice afterwards with no short, cut, damaged leaves. In favorable conditions, they will send up some new shoots quickly and look fairly nice. The main adult plant still looks nice and uniform after repotting as it has not been cut.  The best part of this propagation method is that you get exactly what you wanted. The plants have the same color and pattern as that of the parent.         

Some short varieties of Sansevieria trifasciata ‘Hahnii’. On left is the wild type coloration, the middle front has an all dark variety, and on the right is ‘Golden Hahnii.’ Photo by mrl2024.

The Sansevieria group can be divided into two types, those with flat leaves and those with cylindrical leaves. Of those two groups, there are species/varieties that grow tall and some that grow short. The tall ones make great floor plants while the shorter ones do well when placed on a table. Most of us are familiar with the tall green snake plant with horizontal dark green stripes.  There is also a very similar one that has gold edges to each leaf. These have been around for many decades. There are some absolutely stunning new varieties on the market today that have selected for any of the colors found in these older varieties. For example, there is one called ‘Moonshine’, which has no pattern in the leaf at all, instead being pale green. Another interesting one is called ‘Hi Color’, which has more yellow than green in the leaves. The yellow is not simply along the margin, but found in the main area of the leaf as well. There are others that are selected for such a dark green that it almost approaches black in color. One of my new favorites is a different species called Sansevieria masoniana, commonly referred to as “whale tail,” “shark fin,” or some combination thereof. These can get up to 4 feet tall with proper growing conditions in a greenhouse, but generally smaller in a home setting. No matter which one you choose, you really cannot go wrong with these plants. They are readily available at most nurseries, garden centers, and home stores, so why not pick one or two up and brighten up your home?       

Matthew Lisy PhD

UConn Adjunct Professor

 

Cold Tolerance in Houseplants: An Unintentional Experiment

There are a few different ways that people keep houseplants. Some people place the plants in their homes, and then leave them there permanently. For others, the houseplants are simply overwintering in the house, but their true home is outdoors. I tend to be the second type. This type of behavior leads to some problems, the worst being where do you put all the plants in the winter. For temporary housing, it is difficult to ensure the plants have adequate light, water, and temperature. It is fairly easy to water the plants, and with the copious amounts of LED fixtures on the market today, light is no longer that difficult either. Temperature, however, can be a bit tricky and potentially expensive.

I like to put my plants in the basement for the winter. It is easy to maintain them, and if I spill a little water it doesn’t really matter. Normally, it is best to keep tropical houseplants above 50 degrees F, but 60 F is even better. My basement is generally in that range, but with the severe cold spells we have had this winter, the temperatures have dropped into the upper 40s. The other important thing to remember is that heat rises. The floor of the basement can be as much as ten degrees colder than shoulder height on a human. There can be pockets of cold that pool in areas imperceptible to us. There are a number of solutions to all these problems, but that is beyond the scope of this blog. I brought my houseplant collection in and due to the cold spells completed an unintentional experiment! I will discuss the results here in hopes that others can learn from my misfortune.

First of all, it is important to realize that each species will have its own temperature preferences.  It is not uncommon for one species to be able to tolerate the cold, and yet another closely related species will not. In the field of Ecology, there is a well know optimal zone that our houseplants prefer. These are temperatures from about 60 to 90 degrees F. Now, not all houseplants fit this zone, but I am generalizing for the purposes of this discussion. Outside of this range, are the zones of stress. The plants may still live in this range for a short period of time, but this is not ideal or preferable.  For example, let’s say on the cold side we go down to 50 degrees, and on the warm side 100 degrees F. Beyond the zones of stress are the zones of intolerance. This is where the temperatures are too extreme and the plants cannot live. In my fictious but somewhat realistic example, let’s say below 50 and above 100 degrees F. Plants usually don’t immediately die, but could suffer leaf drops or dying leaves. 

The rare and beautiful Philodendron ‘Silver Stripe’ does not seem to mind the cold one bit. Photo by mrl2023.

There are many reasons plants cannot live outside of a certain temperature range. For one thing, if it gets too cold and the tropical plants are subject to freezing that really needs no explanation.  On the other end, too hot and they may desiccate, or dry out faster than they can replenish the water. Afterall, they are in a relatively small pot with limited moisture. Beyond that, one of the greatest obstacles for our plants (and everything else) boils down to chemistry. Living organisms are full of all sorts of chemicals that undergo reactions. If our enzymes that make these reactions happen faster and with less energy are subject to temperatures beyond their ideal range, they may denature, or change shape, in a way that makes them unusable. Think of breaking your house key, and then trying to use the remaining piece to unlock your door – it won’t work!  So, for our houseplants, even though they are not subject to extreme hot or cold, temperatures outside their ideal range may not allow them to live because the chemical reactions necessary to maintain themselves simply do not work. For some, this process happens quickly, but for other species, it is a slower process. Each species has a different tolerance level.

The groups of mostly tropical houseplants I will discuss here are by no means an exhaustive list.  These are simply a group of plants that were subject to the cold basement temperatures during some of our cold spells. For plants in the rest of my house, they were all fine. I heat the house to a nice toasty 55 degrees F but have supplemental heat in the areas we occupy often. That 55 degrees F seems to be a comfortable minimum threshold for most houseplants. Be careful not to over water in cold temperatures as that easily leads to rot and subsequent death!

Cacti and succulents have the most cold hardiness. I have kept this group of plants in cold basements for years without any issues. It is important to give them just a little bit of water.  These plants are not usually growing at these temperatures, but rather sort of ‘chilling out’. They will resume active growth when placed outside next spring, or when the basement warms up provided there is adequate light. I know a number of cacti and succulent collectors that have simple hoop houses outside with two or three layers of plastic that are heated to a max of 50 degrees F with no troubles. I would advise doing your own research for your specific species of plants should you desire to embark down this path.  

The Gesneriads, of which I am so fond, love cool basements. This group includes African Violets and Cape Primroses. They actually prefer these cooler temperatures, but will suffer in warmer summer months. Pothos also seems rather tolerant of the cold temperatures, although their leaves seem a little droopy. One exception here is the Scindapus treubii ‘Moonlight,’ which died almost immediately. The Philodendrons are a real mixed bag. Any of the larger-leaved floor plants seemed to die almost immediately even at the 50-degree mark. The Philodendron “Pink Princess” and similar types seemed to tolerate the cold up until about February, and now are showing signs of extreme stress. These I am going to move! The hanging basket species, with the exception of the ‘Micans’, seem to be looking fabulous in the cold and not even bothered at all.  All of my ferns do not seem to mind one bit either. All of the Calathea and Sansevieria species are struggling or dying. The always raved about ZZ plants (Zamioculcas zamiifolia) both died almost immediately in the cold temperatures as well. I had both the green and black varieties.  The last plants I will comment about are the Poinsettias. These are difficult to grow due to their sensitivity to temperature, specifically cold. I once had the greenhouse heat stop working one evening. I discovered this the next day and many of the plants dropped their leaves. Even buying them at the store and walking out to the car can result in dropped leaves. If possible, these should be wrapped before leaving the store. Most other houseplants can tolerate the trip home in a cold car, but try to buy them on your way home so they don’t spend too much time in the car.

The Rabbit’s Foot Fern, along with all the ferns in my collection, are not harmed by cold spells. Photo by mrl2023.

Well hopefully my little unintentional experiment with the cold will help people decide where to overwinter their houseplants. I may need to heat that space slightly in future years if I decide to move some of those sensitive plants into that location for the winter. To avoid the coldness of the floor, a board placed on cinder blocks can provide some protection, as can an overturned flower pot underneath the one in which the plant is growing. Isn’t it wonderful knowing that Spring is just around the corner? 

Matt Lisy PhD, UConn Adjunct Professor

 

Bonsai for Beginners

As the winter weather intensifies this season and outdoor gardening tasks come to a close, you may be wanting to turn your attention indoors, to where you can care for plants in the warmth of your own home. Raising a bonsai tree is the perfect indoor hobby for anyone who enjoys connecting with nature or creative expression, and a great way to exercise your green thumb during the winter months. Since starting my first bonsai tree about a year ago, I have come to love the patience and calmness that this activity brings me. I hope to pass along some of the gardening tips I’ve learned, as well as motivation for anyone else interested in beginning a bonsai journey of their own.

So, what exactly is bonsai gardening? A bonsai plant can be any species of tree which is grown in a shallow container, and shaped to produce the miniature version of a tree in nature. Bonsai is a Japanese art form which was derived from ancient Chinese practices and influenced by Buddhist philosophy. The practice of bonsai is enjoyed by gardeners all over the world today, as a challenge to one’s skills and artistry and a symbol of peace and balance in nature. While some professionals take years to master the practice, anyone can get started as a beginner in bonsai and experiment with what the art form means to you.

Some impressive examples of bonsai art. Images from Wikimedia Commons.

For beginners looking to get started quickly with bonsai, buying nursery stock from a local nursery or bonsai shop is a simple way to achieve a successful tree. These young plants can be grown and shaped right away to start practicing with bonsai care. The professionals at a nursery or bonsai shop can also be a great resource for tips and advice to help beginners. Bonsai trees come in many different varieties, so it is important to choose which species is best for you and your environment. If you’re planning to grow a bonsai indoors, look for a sub-tropical tree species such as Ficus or Jade. For outdoor bonsai, some popular species are Juniper bonsai and Chinese elm.

An equally important decision to start your bonsai is selecting the right pot for planting. Traditional bonsai pots are wide and shallow, with holes for drainage and wiring to keep the tree in place. They are commonly made out of ceramic and come in a variety of colors and designs to suit your aesthetic. Bonsai trees also require the right soil mix for proper health and moisture. Look for a soil made for bonsai with the right mix of akadama, pumice, and lava rock for your tree species.

Now that you know how to start growing your own bonsai tree, let’s get into some basic plant care tips to keep in mind when practicing the art of bonsai. The first and most important step in bonsai care is watering. It’s best to water your tree as needed when you notice the soil is slightly dry, rather than sticking to a strict schedule. I like to water my miniature jade bonsai by submerging it in a container filled with water until the roots are fully soaked, then letting the excess water drain from the pot.

Another helpful tip to keep your bonsai healthy is fertilizing the soil regularly. Because bonsai trees are confined to small pots, it is important to replenish those soil nutrients for a happy bonsai tree. I use a fertilizer specific to tropical bonsai which can be found at a bonsai nursery, and apply a spoonful around the edges of the pot about once a month before watering. Be sure to follow the instructions listed on your bonsai fertilizer for proper use.

A crucial element to the practice of bonsai is pruning and shaping your tree to achieve that signature bonsai look. The way you choose to prune your tree can vary depending on the species and desired shape, but it may take some time to experiment with which techniques you like best. To me, the learning process of pruning is very therapeutic and one of the most fun aspects to growing a bonsai. There are plenty of online resources you can go to for help and inspiration in establishing your bonsai design. In general, here are some guidelines to follow when deciding how to shape your tree:

● A good time to prune your bonsai is about every 2 months when new growth is forming

● Use your fingers to pinch off unwanted leaves from your tree

● Use sharp bonsai scissors to trim or remove certain branches, including those that are too long, dead, crossing, growing upwards, or blocking the view of your tree’s design

● Make your branch cuts close to the main stem/trunk to help incision wounds heal quickly, but be careful to not damage the trunk

● Removing no more than 1/3 of your plant’s foliage will keep it healthy while promoting growth

● Consider the use of bonsai wiring to train and shape tree branches to fit your design. This step should be done with care to avoid damaging your bonsai.

Growing an indoor bonsai tree during the wintertime is a perfect way to bring life and color to your home, and with a bit of patience and care I hope you too will find this commitment to be very rewarding!

Laurel Humphrey, UConn Plant Diagnostic Lab