Can You Grow Arrowhead Plants in Water?
If you’ve propagated arrowhead plants before, you probably know that arrowheads can be rooted in water, after which they can be moved to a pot.
But what about growing arrowheads in water? Can it be done? Turns out, you can not only root arrowheads in water, but you can grow them too!
Before I get into the details of growing arrowhead vines in water, here’s a quick primer on how to root arrowhead plants in water.
Rooting Arrowhead Plant in Water
If you want to grow arrowhead vines in water, the first step is to learn how to root stem cuttings in water.
Once you know how to do that, you can focus on meeting the requirements of a mature arrowhead plant.
Here’s a quick step-by-step on how to root the plant:
Step 1: Select a healthy stem cutting
Make sure the cutting is healthy and pest-free. Choose a stem that is neither too mature nor too young. These are the ones that yield the best results when rooted.
Step 2: Cut below a leaf node
The small bumps on the stems of arrowhead vines are called nodes. They can shoot out new growths or roots.
It’s important for your stem cutting to have at least one leaf node. So, cut the stem just below a leaf node.
Make sure the cut is clean and sharp.
Step 3: Place the cutting in a glass jar
If you just want to root the cutting, then move it to a pot, don’t worry about the type of jar or glass you choose.
Later, I will explain why it’s better to choose a darker colored jar or vase if you want to grow them in water.
Step 4: Keep in a warm, humid environment, out of direct sunlight
Replace the water at least every 3-4 days to keep it clean. Use chlorine-free water and make sure it’s not too cold or too warm. Use only room temperature water
How soon will the roots emerge? It depends. Factors like how good your cut was, whether the stem was healthy enough, and whether the cutting is kept in an optimal environment can all influence how soon roots will grow. But generally, you can expect to see root growth within 1-2 weeks.
Growing Arrowhead Plant in Water
Once your arrowhead plant stem cuttings have developed roots, you have the option to move the cutting to a pot or continue growing it in water.
If you choose to grow it in water, its requirements will largely be the same as if you would place it in a potting mix, with a few differences.
Here’s what you should know about growing an arrowhead plant in water:
If you’ve grown any aroid plants before, you know that they will enjoy bright, indirect light the most.
They will survive in dimmer light as well, but they need bright light to thrive and develop healthy growth.
An arrowhead vine that doesn’t get enough light will grow leggy. Its leaves will be smaller and grow sparse. To get the best results, you need bright light exposure.
Keep the plant near a western or eastern window or a couple of feet away from a southern window. As long as the sun doesn’t hit the plant directly, it’s going to be fine.
If lack of light is a problem, you can use a grow lamp to provide enough light. Arrowhead plants will grow just as well in artificial grow lights.
For plants grown in transparent jars or vases, too much sunlight can be a problem because of algae growth.
To reduce or minimize the chances of algae overgrowth, I recommend you use a darker colored jar, which can block some of the light reaching the water.
Similarly, when you’re changing the water in the jar, give it a good scrubbing on the inside to remove any algae build-up.
The problem with algae is that they can compete with your arrowhead plant for resources. It’s best to suppress their growth so that your arrowhead plant won’t suffer nutritional deficiencies because of an overgrowth.
Beyond keeping an eye on indoor temperature and maintaining it within the range that’s ideal for arrowheads (65 F-85 F), you also need to be careful about water temperature.
Sudden temperature fluctuations or something as simple as a cold draft or hot air hitting the plant directly can trigger temperature shock and tissue damage.
Symptoms of temperature shock can range from foliage loss to plant death, so you need to be careful about maintaining proper temperatures.
Temperature shock can also be induced by using very hot or very cold water in the jar, so that’s also something I recommend you be careful about.
I’d argue that humidity levels aren’t as problematic for arrowheads grown in water as it is for arrowhead plants grown in a pot. After all, water that evaporates from the jar can usually keep the plant happy.
Still, I do recommend maintaining average indoor humidity levels in any room where you keep arrowhead plants, regardless of the growing medium.
If you can, keep your arrowhead plant in a naturally humid location like a bathroom or kitchen. The more humid the area, the better for your arrowhead plant.
Clearly, given the growing medium, you don’t need to worry about watering arrowheads, but you do need to worry about changing the water in the jar or vase.
When to replace the water of your arrowhead plan? Ideally, you should replace it at least once a week. Still, I recommend you keep an eye on how cloudy the water is or whether there’s any algae growth.
If the water becomes cloudy, replace it more often. As I mentioned, give the inside of the jar a good scrubbing to remove dirt and algae build-up.
Use chlorine-free water and make sure the water is room temperature. If you’re using tap water, let it sit overnight. Chlorine will evaporate.
Even though you don’t have to bother watering an arrowhead plant you grow in water, you still need to replace the water every now and then.
Another important aspect is the water level in the jar. The water level should be high enough so that the roots remain under water, but not as high as to reach the leaves.
When the water reaches the leaves, the leaves can start rotting fouling the water and triggering a ripple effect that can even affect the roots of the plant.
Potted arrowheads benefit from monthly fertilizing with a weak solution. Same holds true for water-grown arrowheads.
Use a water-soluble liquid fertilizer that’s diluted to a weak solution. Add the solution to the water of your arrowhead plant monthly.
It’s important to start with a weak solution to assess the fertilizer needs of your arrowhead plant. Be careful to dilute the fertilizer every time, otherwise you risk overfertilizing your plant.
Obviously, there’s no need to repot your water-grown arrowhead. But what if you wanted to? What if you’d like to move your water-grown arrowhead plant to a pot and continue growing it in a pot?
Technically, there’s no impediment to doing that. Unfortunately, these types of transfers are not always successful.
That’s because water-grown arrowhead plants have a weaker root structure than soil-grown ones.
They’re visibly thinner, sometimes even hair-like, which means that they’ll struggle once they’re moved to a pot.
I’ve had some successes with moving arrowheads from water to soil, but the highest success rate was usually when I made the move a couple of weeks after rooting the stems.
Moving a pot-grown arrowhead plant to a water medium can also be tricky. Since the roots aren’t used to sitting in water, there’s a chance they start rotting, especially if the roots still have a bit of dirt on them.
Moving the arrowhead plant back and forth from one growing medium to another can be a hit or miss.
Arrowhead vines benefit from pruning, especially if you want them to grow bushy or if there are long, leggy stems that need to be cut back.
Pruning can be done throughout spring and summer, by pinching back growths that are irregular or that you deem to be out of place.
Always try to cut just below a leaf node and make sure to use clean tools to prevent the spread of fungal diseases or pests.
Arrowhead plants that grow in water can be affected by the same diseases that affect arrowhead plants that grow in a pot.
Aphids, scale insects, spider mites and fungal leaf issues are the chief complaints. Luckily, arrowhead plants are resilient and a bit of prevention (occasionally spraying the plant with neem oil) can prevent some of these problems.
How Long Can Arrowhead Plants Grow in Water?
As long as you take good care of arrowhead plants, they can grow indefinitely in water. At some point, as the plant matures, growth will slow down.
Keeping the jar clean and replacing the water regularly as well as fertilizing the plant will keep it healthy. Pruning it regularly will also encourage new growth.
Can Arrowhead Plants Grow Underwater?
Arrowhead plants don’t grow underwater. Despite their love for humidity and their ability to grow in water, they’re not underwater plants.
If you’re looking for an aquarium plant, look specifically for underwater aquarium plants. Arrowhead plants will die if you attempt to grow them under water.
That said, you can grow arrowheads in the aquarium but without their leaves touching the water. The waste produced by fish can act as a fertilizer for arrowhead plants.
Needless to say, arrowhead plants are not suitable for saltwater aquariums, only freshwater ones.
Just like pothos plants or philodendrons, arrowhead vines are also easy to root and grow in water.
If this is the growing medium you choose, you’ll need to adjust your normal care routine to account for the problems that can arise when growing plants in water.
Algae growth, water cleanliness, water levels, and fertilizing are the main areas where you’ll need to shift your attention to make the necessary changes. Overall, the plant’s care requirements remain the same.
Hopefully, you’ll find my tips useful should you ever decide to forgo the classic growing medium for arrowhead plants and switch to growing arrowheads in water only.