Snake plants, or mother-in-law’s tongue (Dracaena trifasciata, formerly Sansevieria trifasciata), with their distinctive, sword-like leaves standing tall are well-known houseplants that are loved for their easy care and stunning looks.
There aren’t many problems that plague Snake Plants, but sometimes under certain conditions, they may develop the dreaded root rot.
Key Tips: Snake Plant Root Rot
Snake Plant root rot is caused by overwatering, resulting in oxygen-starved roots. Prevent it with well-drained soil and waiting for the top soil to dry before watering. For suspected root rot, trim rotten roots, dry the plant, then repot in fresh soil. Regular plant checks help avoid root rot.
What Is Root Rot?
Root rot is a general name for several soil-borne fungi that will attack plant roots: Phytophthora spp., Pythium spp., Fusarium spp., and Rhizoctonia solani.
Spores of these fungal diseases are in garden soil everywhere and also in your potting mix. Their spores, especially those of Phytophthora and Pythium, can remain dormant in the soil for a long time, waiting for the right conditions to grow and flourish.
The Main Reason Snake Plants Get Root Rot
As stated above, overwatering, or too much water, causes root rot!
All soil has a structure with air spaces that allows oxygen to move through the soil and around the roots. When these spaces are constantly filled with water (overwatering), the plant’s roots can’t “breathe,” creating the right condition for fungal spores to grow.
Overwatering mainly comes from (yes!) watering your snake plant too much too often, but other factors can also play a part:
- Heavy, poor-draining soil: When the soil is heavy and dense without enough air spaces, it will hold the water and not allow it to drain.
- A pot without a drainage hole: Water will build up in a pot without a drainage hole.
- Low temperatures: Water will evaporate more slowly from the soil in low temperatures, and the plant will grow more slowly and not use up water as quickly as in warmer temperatures.
- Low light: Plants grow more slowly and don’t use up as much water in low light as they do in higher light.
- Too big a pot: The amount of soil in too big a pot holds more water than a plant can use and will dry out slower than the amount of soil in a smaller pot.
- Watering while the plant is dormant: Snake plants slow down their growth in the winter and need less water.
Symptoms: What Root Rot on a Snake Plant Looks Like
To diagnose a case of root rot, look at both the leaves and the roots.
You may also see small insects flying up in a cloud when you bump against the pot. These are fungus gnats, and they are a symptom of overwatering. If you see this happening and the soil is constantly wet, it may be a sign of root rot.
Now look below the soil. Turn the pot on its side and gently pull out the root ball. Shake the soil off of the roots so that you can get a good look at them. Healthy Snake plant roots are firm, white, or light orange, and older roots are bright orange.
If some of the roots are black and mushy with no firmness and they smell bad, you can be sure your plant has root rot. Now what?
How To Save & Repot Your Snake Plant With Root Rot
In order to treat your Snake plant for root rot, you’ll need to get rid of the infected roots, leaves, and soil.
1. Wash the Roots
First, wash the roots thoroughly to eliminate the infected soil stuck to them.
2. Cut Off the Rotten Roots
Next, cut all of the black, rotten roots off with clean scissors or a knife.
3. Drench the Roots
Drench the remaining roots in a solution of one part 3% hydrogen peroxide and three parts water. This will kill the fungus and bring oxygen to the roots. Neem oil, or a commercial fungicide with copper as an ingredient will work, or cinnamon powder, which is a natural fungicide, is also effective.
4. Prune the Leaves
If you cut off a third of the roots, remember that you’ll have to trim a third of the leaves, too. Use only clean scissors or a knife (washed after cutting the roots) to cut the wilted, yellow leaves back, but you may have to cut some healthy leaves as well. (Don’t feel bad, though, because the healthy leaves can be propagated.)
Cut the leaves right at the soil level where they attach to the rhizomes.
If the root rot has only infected only a few of the roots and none of the leaves, just prune the roots and let the leaves alone.
5. Repot the Plant
Next, repot the remaining Snake plant in fresh, moist, well-draining soil in a clean, new pot with a drainage hole. If you’re going to use the old pot, wash it thoroughly with soap and water before adding the fresh soil.
6. Help the Plant Recover
A damaged plant that is repotted (or actually, any repotted plant) needs some TLC to recover. You will want to stress it as little as possible, so set the plant in medium light out of the direct sunlight in a warm location with no drafts.
Don’t water your plant after repotting because the moisture in the soil will be enough to help it through its recovery. Don’t fertilize it, either, because that would put undo stress on the plant. You can begin watering after a week or two and fertilizing in about a month after repotting.
Propagating the Healthy Leaves
If you had to prune off some healthy leaves to balance the root pruning, you can easily propagate them and start new plants. They can be propagated with leaf cuttings or by division.
Leaf cuttings can be propagated in either water or soil.
For water propagation, cut a leaf into several pieces with a sharp knife and set them in a bowl or jar right-side up in bright, indirect light. Change the water every four or five days to keep bacteria and algae from growing. And then, when the roots are 2” to 3” long, plant them in fresh potting mix and only water when the soil is dry or almost dry.
For soil propagation, cut sections of a leaf and set them in well-draining potting soil right-side up in bright, indirect light. As an option, you can dip the bottom end of the cutting in rooting hormone before you place it in the soil. It will take a number of months before the cutting will develop roots.
NOTE: Be sure to always orient your cuttings right-side up in the water or soil. They will not develop roots if they are upside-down.
Division is probably the easiest way to propagate your Snake plant. If you have multiple leaves growing in your pot, or a pup that you want to separate, brush away the soil to gently expose the rhizomes, and cut or break them to separate the plants.
Allow them to callus over in the air for a couple of days, then plant them in separate pots in fresh potting mix. Only water when the soil is dry or almost dry.
Another way to propagate by division is to cut or break off separate pieces of healthy rhizomes that are not attached to a leaf. Allow it to callus over for a couple of days and then put it in well-draining soil in a small, shallow pot in bright, indirect light.
Water it whenever the top of the soil is dry until it develops roots. Then plant it in a larger pot in well-draining soil.
How To Prevent Snake Plant From Root Rot
Snake plants developed as drought-resistant succulents in the hot, dry climate of West Africa where they are native. If you can mimic their native conditions as much as possible, you will be able to keep your plant healthy with no trace of root rot.
In addition to watering, the soil, pot, and environmental conditions around your plant, like the amount of light, humidity, temperature, and time of year will influence how fast the soil dries out.
Here is a list of Dos and Don’ts for preventing root rot and keeping your plant growing beautifully.
Don’t keep to a watering schedule! Do test the soil with your finger to determine how moist or dry the soil is. Dig your finger or poke a chopstick 2 to 4 inches down from the top. Do only water when your finger or chopstick comes out dry. This will prevent the soil from accumulating too much moisture.
Don’t water shallowly. Do run the water through the soil until it comes out of the drainage hole. The soil needs to be moist down to the bottom of the pot for the root system to access the water.
Don’t use tap water. Snake plants can be sensitive to chemicals, so do use distilled or rainwater for your plant.
Don’t use heavy, poor-draining soil. Do use succulent or cactus soil or an all-purpose commercial indoor plant mix that you amend with perlite, coco coir, peat moss, coarse sand, or pumice to loosen and lighten the soil.
You want the soil to have as many air spaces as possible for the best drainage. Well-draining soil has a lot of these air spaces so that water can run through it, moistening the solid parts and still maintaining air around the roots.
Don’t use a pot without a drainage hole. Do use a pot with at least one drainage hole so that excess water doesn’t build up in the bottom of the pot and choke the roots. Good drainage will go a long way to prevent root rot.
Don’t keep your plant in a place with low temperatures. Do keep your Snake plant in temperatures between 65 and 75 or 80 degrees F. Below that, their growth slows down and they don’t use up the water in the soil as quickly. In addition, the soil moisture itself will dry out more slowly in lower temperatures.
Don’t keep your plant in low light. Do keep your plant in bright indirect light with a few hours of direct sun. That way, it will absorb the soil water steadily as it creates its food energy by photosynthesis. This will promote its growth and keep the roots healthy.
Don’t use too big a pot. Do use a sized pot that is no more than 2 or 3 inches away from the plant at the edge. Rootbound plants will have roots growing out of the bottom of the pot and circling the pot on the inside. When repotting a rootbound plant, only go one size up.
Don’t water while the plant is still dormant. Do only water during the spring and summer. When temperatures drop in the fall and winter, all varieties of Snake plants slow down their growth and only need to be watered once or twice during that time.
Using fertilizer is not necessary at all in the fall and winter. Enough nutrients are in the soil to carry them through.
Root rot is a serious fungal disease that can kill your plant, so it’s best to take action sooner than later. Cutting away the dead roots and leaves, treating the remaining roots, and repotting will give the plant a new start.
Watering correctly and giving the plant the conditions it needs for its best growth will assure that you have a healthy Snake plant for years to come.
Nancy has been a plant person from an early age. That interest blossomed into a bachelor’s in biology from Elmira College and a master’s degree in horticulture and communications from the University of Kentucky. Nancy worked in plant taxonomy at the University of Florida and the L. H. Bailey Hortorium at Cornell University, and wrote and edited gardening books at Rodale Press in Emmaus, PA. Her interests are plant identification, gardening, hiking, and reading.