Cast iron plants are easy to care for and as low-maintenance as houseplants can get. Experienced plant parents know these beautiful plants can easily be propagated in water rather than spending money on a new plant.
Cast iron plant propagation in water is done by cutting plant stalks and placing them in a jar filled with water. You can propagate a cast iron plant using water in short-term situations, but it’s best to propagate it through division.
In this article, I’ll share a list of materials you’ll need and a complete list of steps to follow to successfully reproduce a cast iron plant. Keep reading to learn more about cast iron plants and how to best set them up for success in your home.
What You’ll Need 5o Get Started
Plant propagation requires a small up-front investment, but fortunately, the items are all relatively inexpensive and will last a long time.
The following are items and tools to have on hand before you start propagating new plants, along with a few suggestions on what to look for when shopping for them:
Glass Jar
You’ll need to place cuttings in a glass jar to allow them to develop roots. Ideally, the glass jar should be vase-like and slightly narrow at the neck or towards the top. This shape helps to hold the cutting in place as the roots develop.
Another key benefit of using a glass jar is that light can pass through to the roots, helping the plant photosynthesize. This is why propagation kits always come with clear glass jars. It truly is the material that best sets the cuttings up for success.
You can use a small canning jar or a jelly jar that has been washed out. Just be cautious about setting the cutting into the jar so the entire plant won’t slip under the water and rot out before the roots can become established.
Using Ceramic Vases for Water Propagation
Alternatively, you can use ceramic or other non-porous materials to propagate cast iron plants and cuttings in water.
The main benefit of using glass is that it allows you to easily monitor root development without disturbing the cutting, so you can also use ceramic vases and other non-porous containers if you wish to.
Potting Medium
You’ll need a potting medium appropriate for the cast iron plant once it’s ready to come out of the water and be transferred into a pot. This species likes a fast-draining, quick-drying soil that allows the root system to dry out quickly.
Potting soil is designed to hold moisture, so it is not your best choice for cast iron plants. You can add sand or sphagnum peat moss to the soil to help it drain more quickly.
New Plant Pot
It’s best to have a pot that’s slightly larger than your plant once its root system has developed and it’s ready to go in the soil. Cast iron plants prefer dry soil and a dry root system, so a pot that drains water away from the roots is best.
A ceramic or plastic pot with drainage holes on the bottom is the best option. It can be placed in a drip tray and moved into a sink or tub for watering. The drainage holes help keep the roots from getting rot or the soil from becoming waterlogged.
Organic Fertilizer
Before propagating, you should already have a routine for fertilizing your houseplants. If not, find an organic fertilizer to help the root system establish itself in its new soil and pot as quickly as possible. Organic fertilizer can provide your plants with additional nutrients that may not be present in their current soil environment.
Other Helpful Items
Some items aren’t essential to plant propagation, but they make the job easier.
Here are a few of the things that I’ve found to be helpful and have acquired over the years in my plant propagation kit:
Cutting Board
For anyone who doesn’t have a greenhouse or barn, you’re likely propagating plants somewhere in your home. I like to repot and propagate plants in my kitchen because I have access to water and trash and have ample work surfaces at the right height to avoid back pain.
However, plant division and propagation can be filthy, and I like to keep my kitchen clean and pristine for food preparation. Instead of working directly on my surfaces, I want to use a large cutting board.
Thin Paring Knife
Sometimes, you need a thin, flexible knife to either take a cutting or gently separate roots or plant clumps. Rather than use my expensive kitchen knife, I bought some thin, inexpensive stainless paring knives.
Rooting Compound
One final item that is helpful, although not essential, is a powdered rooting compound. Many plants will quickly develop roots without rooting compounds, but it helps develop robust root systems more rapidly than just placing a cutting in water.
Again, it is best to use a powdered compound where the cutting can be dipped into the powder before it is placed in water. Liquid works, but it more easily washes off when plants are propagated in water. The powder will stick to the base of the cutting far longer and help with root development.
How to Propagate Cast Iron Plants in Water
Once you have your supplies on hand, you are ready to propagate a new cast iron plant. Take the mother plant you’ll use into your workspace with all your tools and materials.
It’s best not to propagate a cast iron plant on the very day it has been watered. Pick a few days after you’ve watered it. You want the plant and soil to both be moderately dry.
Additionally, it’s best to take cuttings and propagate new plants during the growing season. Taking cuttings or dividing plants stresses the mother plant. You don’t want to disrupt the period of dormancy by forcing the plant to put effort into survival.
It also is more difficult for cuttings to thrive when taken during a period of dormancy. If you take cuttings in early spring when a plant is just starting to grow, the plant is naturally inclined to grow and develop at that time.
Follow these steps to reproduce cast iron plants through water propagation:
- Fill your glass jar with room-temperature water.
- Use your thin knife to make a clean cut at the bottom of the stalk. Instead of making a straight cut perpendicular to the ground, make a cut at a 45-degree angle. Doing so allows more surface area to touch the water and potentially establish roots.
- Dip the cut end of the stalk into the rooting compound, knocking any excess off. I usually leave the plant on the cutting board for 30 minutes or so at this stage. This allows the rooting compound to cover the cut entirely and dry out slightly before placing it in the water.
- Place the cutting into the water. It’s best to only put a few inches of the stem in water, keeping any leaves and the base of leaves out of the water because they could rot.
- Remove all but one top leaf from the stalk.
- Place the cutting in the glass jar near a window, ensuring the cutting doesn’t receive direct sunlight. Most cuttings must be placed in direct sunlight to root, but cast iron plants are intolerant of direct sunlight.
New Root Growth Takes Some Time in Cast Iron Plants
Cast iron plants can’t tolerate direct sun exposure often needed to generate new root growth. Because of the plant’s light-shy nature, new root growth will take longer than anticipated.
If you successfully grow roots on the stalk, allow the roots to establish, producing at least 1 to 2 inches (2.5 to 5 cm) of growth before you attempt to transplant the stem.
Follow these steps when transplanting the stem:
- Dip the stalk end along with the roots into the rooting compound, shaking off any excess.
- Allow the stalk to sit and dry for up to 30 minutes.
- Prepare the pot by adding potting medium to the bottom half of the new pot.
- Poke a hole in the center of the potting soil using a finger.
- Place the rooted stalk roots down in the potting soil and cover the remainder of the plant with potting soil, patting it loosely.
- Water the plant lightly and monitor the plant’s growth, taking care to check the stalk for signs of rot. Water the new plant as frequently as you typically water your parent cast iron plant, taking care not to overwater it, given that it is in a smaller pot.
Water Propagation Is Not the Best Way
There are better methods than water propagation to produce new cast iron plants. This is because cast iron plants naturally propagate through an expanding root system, not by generating new growth above the soil.
Nevertheless, there are times when it makes sense to try propagating a cast iron plant in water. One of those times is when a plant stalk breaks off or falls from the main plant. When this happens, it does not take the root system with it, so you can attempt to root the stalk using water.
Division Is the Easiest Way to Propagate
More cast iron plant owners prefer to reproduce their plants through division. When dividing a plant, parts of it can be torn away from the parent plant. These pieces can sometimes be propagated into a new plant.
Once you have divided and planted pieces from the cast iron plant, and you have areas of the plant stalk with tiny bits of roots attached, you can better establish the root system using the water method. It also sometimes is necessary to put them in water because you’re out of potting medium or another pot to place the new plant.
To use the water method, follow the same basic steps for a plant without a small portion of roots attached:
- Dip the base with the roots in the rooting compound. Leave it to dry while preparing your glass jar.
- Fill your jar with room-temperature water and allow it to sit out while you wait.
- Once approximately 30 minutes have passed, set the stalk covered in the rooting compound in the water, taking care to only cover the bottom few inches (5.08+ cm) with water. Because this plant already has a bit of root system attached, it should take less time to see the roots further established through the sides of the glass jar.
- Once the roots are established, dip them in the rooting compound and plant them in a new pot as you would any other plant.
- Water the plant lightly, adding more potting medium as the soil tamps down.
- Monitor the plant and integrate it into your regular watering regimen.
Ways to Save a Dying Cutting
Water propagation is a challenging way to produce new cast iron plants. It requires a great deal of patience, too. Even in plant species that are more successful via water propagation, some cuttings simply aren’t going to survive.
Consider any of these options to save your plant:
Move It to a Slightly Darker Location
If your cast iron plant cutting looks rough, make sure it isn’t getting direct or too much bright, indirect sunlight.
Assess for Signs of Stress
Look at the water in the jar to check if your cutting looks a bit stressed. If the water appears green or cloudy, dump the old water and replace it with fresh room-temperature water. Don’t worry about re-dipping the roots into the rooting compound.
Plant in a Potting Medium Instead of Water
Plant your cuttings in the potting medium rather than put them back in the water. Dip the roots or the base in the rooting compound and plant it in a pot prepared with fresh soil and a hole for the cutting. Add soil to bring it up to nearly the top of the pot, and water the plant lightly.
Look for Black Roots or Stalks
If the stalk or the roots start to blacken at any point, the cutting has failed. Don’t let this get you down.
Instead, throw the cutting away, wash and sanitize your glass jar, and try again when the time of year and conditions are right. The only way to learn what works well with your plants and in your home is to keep trying.
Reasons Cuttings Fail After Being Planted in Soil
Sometimes, a cutting is successful and generates adequate root systems, but it can also fail once planted in a potting medium. There are several reasons this can happen, but the primary reason cuttings die after planting is overwatering.
Cast iron plant cuttings are particularly susceptible to overwatering because the plant generally doesn’t tolerate wet soil. After planting the cutting, water the new plant lightly and take care not to saturate the soil.
Resist the urge to water the new plant too frequently. In fact, it is often better to ignore the new plant for a bit. It is, after all, a cast iron plant, a species known to thrive on neglect.
Conclusion
Cast iron plants are easy to care for and propagate in water.
I recommend gathering the following tools and materials to get started:
- Vase-like glass jar
- Fast-draining, quick-drying potting medium
- Plant pot with drain holes
- Organic fertilizer
- Thin paring knife
- Rooting compound
It’s best to propagate cast iron plants when they’ve been watered recently. Start by cutting stalks at an angle and placing them in a glass jar filled with water. Wait for new roots to grow before transplanting the stems.
