While many people are familiar with the process of propagating houseplants in water, not everyone knows that you can actually grow your houseplants in water as well. Won’t the roots drown? What about algae growth?
I’ll cover these questions and more in this complete guide to growing houseplants in water. I’ll also provide some recommendations for a few types plants to choose if you are new hydroponics.
- Can you grow houseplants hydroponically?
- Benefits of keeping houseplants in water
- Drawbacks to keeping houseplants in water
- How To Grow And Keep Houseplants In Water
- The best houseplants to grow in water
- Preventing algae growth in hydroponic houseplants
- Preventing root rot in hydroponic houseplants
- Transitioning soil houseplants to water
Can you grow houseplants hydroponically?
Hydroponic growing is a method of growing plants without any soil. Instead, plants are grown in water, allowing for a more controlled environment. We have grown herbs hydroponically, vegetables, and even houseplants.
There are many different ways to grow plants hydroponically. DWC (deep water culture) is one of the most popular methods which involves using an air pump to provide the roots of a plant with oxygen. There are also wicking systems, drip systems, and other hydroponic methods that are popular with growing vegetables in large scale operations.
When it comes to houseplants, these methods are a bit too fussy and complicated for most growers. It’s possible to grow houseplants hydroponically and keep them happy for many years in a simple water and nutrient solution. I prefer to keep the process very simple!
You may wonder, why would you want to grow your houseplants in water? In addition to being a fun indoor experiment, there are many benefits to growing houseplants this way.
Benefits of keeping houseplants in water
- Less issues with pests like fungus gnats, mites, and aphids.
- It’s unique and aesthetically pleasing, and you can watch the roots grow in water over time.
- Houseplants can be propagated in water and then kept in their water vessels to grow for an extended period of time.
- There is no risk of overwatering hydroponic plants. If you tend to overwater your plants, you may really enjoy the ease of growing them in water alone.
- A variety of different houseplants can grow in water, so you can experiment with what you like best.
Drawbacks to keeping houseplants in water
- Plants tend to grow a bit slower. This could be a benefit or a drawback depending on your situation and growing space.
- Water needs to be monitored for algae growth and changed on a regular basis.
- The root systems are more delicate.
How To Grow And Keep Houseplants In Water
The process of keeping houseplants in water is not complicated. In fact, I do not find my hydroponic houseplants to require any more care than my soil-grown houseplants. I change the water as frequently as I would water a soil-grown plant. And, I find there are less issues with pests, making hydroponic houseplants very easy to care for!
Here is my complete process for growing plants in water:
1. Get your plant started
The easiest way to get started with growing houseplants in water is to propagate one of your soil-based plants. Typically, growers propagate their houseplant in water and then transition the plant to soil once roots begin to form. However, you can keep your houseplant growing in water well after the roots emerge!
You can also transition a soil plant to water, but this process is a bit more complicated. See below for instructions on how to do this. To get your first plant started, simply place a cutting of your choice in filtered water (without nutrients) as you would if you were doing a simple propagation.
2. Monitor for root growth
Depending on the type of plant, you can expect new roots to emerge after a few days to several weeks. Some plants just grow roots more quickly than others.
As soon as your roots reach a couple inches in length, you can begin feeding your plant with nutrients. These roots are called water roots, and they are much different than soil roots, most notably for their ability to absorb nutrients in water.
3. Feed your plants and refresh your water
I like to prepare 1 gallon of filtered water with 1/4 tsp of Superthrive Foliage Pro. I use this solution each time I change the water in the houseplant water vessels. This ensures the plants are consistently being fed without giving them too much nutrients.
When keeping houseplants in a water/nutrient solution, I suggest changing the water every 7-10 days. This will replenish the oxygen for the plants, replenish the nutrients, and help prevent algae growth. I give the water vessels a good cleaning with soapy water once a month.
Tip: If you notice the water levels getting low before your 7-10 day water change, you should top the water off in each vessel. This is common in the winter months when the air is dry and the water is evaporating more quickly.
4. Monitor for algae
Growing houseplants in nutrient water and exposing them to light is the perfect recipe for algae. However, it is easy to stay on top of algae growth. You’ll want to change your water frequently enough that the algae growth does not get out of control.
If you do notice green algae forming on the roots of your plants, you can gently rinse the roots off and give the vessel a good cleaning with soapy water.
The best houseplants to grow in water
There are many different houseplants you can grow in water. Some plants are a bit easier to grow hydroponically, especially plants that have adapted to growing in wet areas like swamps. Here is a list of the best plants you can grow in water.
- Pothos – Pothos are well known for their ability to propagate quickly and grow fast with the right conditions. They are a great choice for growing hydroponically and come in many varieties, including variegated varieties.
- Alocasia – Some of our happiest hydroponic houseplants are Alocasias (also known as Elephant Ears). Their big, beautiful leaves are a true statement piece, especially when grown in water.
- Calathea – Calatheas have a reputation for being fussy and difficult to care for. But, I find they grow incredibly well in water. If you’ve had trouble keeping them happy in soil, try growing them hydroponically. Dividing one of your soil-grown plants is a great way to do this quickly.
- Ivy – Ivy is a great houseplant to keep in low-light areas of your home. Spider mites are very attracted to ivy, but not when they are grown in water. This is one of my favorite plants to grow hydroponically.
- Monstera – Everyone loves the Swiss Cheese Plant. After propagating your Monstera Adansonii, try keeping it in water. They typically do very well in this environment.
Preventing algae growth in hydroponic houseplants
The biggest issue with growing houseplants hydroponically is dealing with algae growth. There are many things you can do to stay on top of this and prevent the algae from taking over your plant and competing for nutrients.
- Keep your vessels clean: As soon as you see algae growth or green growing in your vessel, give it a good clean with soapy water. Algae spreads quickly and can get out of control fast.
- Block the light from reaching the water: The mixture of water, nutrients and light is what causes algae growth in the first place. If you are unable to keep algae under control with clear vessels, consider using frosted or tinted jars to grow your hydroponic plants in. You can also cover the outside with paint, tin foil, or dark paper.
- Change your water on a regular basis: Be sure to change the water in the vessels on a regular basis, at least every couple weeks. This will ensure a clean environment for the roots while discouraging algae overgrowth.
- Do not overfeed: While it may be tempting to give your plants extra nutrients, this can lead to algae overgrowth. It is important to provide your plants with nutrients via liquid fertilizer, but do not overdo it.
Preventing root rot in hydroponic houseplants
It may seem strange that you can grow houseplants in water. Won’t the roots drown and die from lack of oxygen? The plant grown in water will actually grow new roots called water roots. These roots are special because they can take in oxygen and nutrients directly from the water.
Soil roots are susceptible to root rot when they are drowning in over-saturated soil. They are not built the same as water roots, and instead, soil roots rely on air pockets in the soil for their oxygen.
In order to prevent root rot, you want to be sure you are replenishing, changing, or topping off the water supply in your houseplant vessel on a regular basis (every 7-10 days is best). This will ensure the roots have access to oxygen.
Transitioning soil houseplants to water
Transitioning a plant that has been growing in soil into water is trickier than growing a propagation from scratch in water. However, it is possible.
Step 1: Choose the soil-grown plant you would like to transition to water. I suggest a small, healthy houseplant that is actively growing.
Step 2: Thoroughly rinse off the roots with room temperature water as best you can. Be careful not to disturb the root system too much. You’ll want to rinse off as much of the soil as possible.
Step 3: Transition the houseplant into a water-nutrient mix. I suggest 1 gallon of water to 1/4 tsp of Superthrive. The plant will eventually grow new water roots, and the older soil roots will die off over time.
Tip: Rinse the roots of your plant off every week with lukewarm water. Any old/dead soil roots should be discarded to keep the vessel clean and to make way for the water roots to come in.
I hope you found this guide to growing houseplants in water helpful. The best way to learn is to get started! Let me know in the comments what houseplants you decide to grow in water along with your results.