LECA–an abbreviation that means lightweight expanded clay aggregate–is a form of passive hydroponics. You might hear indoor gardeners proclaim that every houseplant does well in LECA, but I disagree. Today, I want to tell you which plants don’t do well in LECA? which ones don’t.
The following plants might not do well in LECA:
- Prayer plant
- Elephant bush
- String of pearls
I’ll mention this several times, but many indoor gardeners are able to grow the above plants in LECA. But, even more, indoor gardeners using LECA will experience slowed growth or dormancy and other unappealing side effects when growing the above list of houseplants in LECA.
Let’s see why.
The Lowdown on LECA
First, allow me to refresh your memory on LECA if you missed my recent post “LECA Vs Soil“.
LECA is a soil-free growing medium that utilizes baked clay balls. The clay balls absorb water (some of it, not all) but contain no nutrients. LECA balls can absorb nutrients if you add them to your plant’s container through fertilizer.
To start a LECA garden, you’d buy some clay balls (which are known to be expensive), fill a vase or jar with them, pour in water, and add your plant. The plant’s roots are supposed to take hold of the LECA balls and spread.
For many houseplants, that’s exactly what happens. As I talked about in my article on LECA vs. soil, the best plants for passive hydroponics are the ZZ plant, alocasia, Monstera, spider plant, orchids, begonia, and snake plants.
These Plants Might Not Do Well in LECA
Even plants outside of those on the list above can transition into a passive hydroponics growing medium, but many will struggle. The following plants likely will not do well in LECA, meaning they will likely do better in a traditional soil environment…
Caveat: That doesn’t mean there aren’t success stories among indoor gardeners growing the plants in LECA, just that LECA does not suit these plants most of the time.
The prayer plant or Maranta leuconeura is first on my list.
The houseplant hails from the tropical forests in Brazil. Its stunning coloring–which often features neon red veins–is a reason so many indoor gardeners desire it.
I can see why some people have had a prayer plant or two survive in LECA, as this species is very thirsty and loves to drink water.
However, prayer plants also detest standing water, which means being submerged in a vase of water with LECA balls probably isn’t the best idea.
LECA is supposed to reduce root rot since the clay balls absorb up to 30 percent of the water. This should keep your plant’s roots from being oversaturated, but for a plant that’s sensitive and susceptible to root rot like the prayer plant, it might not be enough.
You can add LECA balls to traditional potting soil. This can improve the drainage, aeration, and sometimes the water retention of the soil.
For the former two qualities, LECA balls in the prayer plant’s soil could be a good idea.
A Marantaceae family member, the stromanthe shares lineage with the prayer plant.
Like the prayer plant, I’d tell you to reconsider growing the stromanthe in LECA balls rather than in traditional potting soil.
Here’s a bit of background. The stromanthe is a tropical houseplant that grows natively from Argentina to Mexico. It’s known as the Triostar and features long, blade-like leaves with dark green centers and lighter green or pale pink edges.
When propagating stromanthe cuttings, you can’t even soak them in water to grow. You need to use a process known as division.
If you’re not familiar with the term “division” as it relates to gardening or propagation:
As if that didn’t make it clear enough that the stromanthe is likely a poor candidate for LECA gardening, this houseplant also hates standing water.
The most common issue that indoor gardeners face when growing stromanthe is root rot caused by overwatering. It’d take a lot of LECA balls to absorb enough water so the stromanthe would feel comfortable enough to grow in a water-filled container.
You’re likely better off using soil.
This succulent, Elephant Bush, can reach sizes of up to 20 feet in its natural habitat, although it’ll probably grow closer to six feet indoors.
Known as the Portulacaria afra, this South African succulent grows long, stiff vines with round leaves.
I don’t want to disqualify succulents and say that you can’t grow any of them in LECA, because it can be done successfully. If you ask your fellow indoor gardeners, I’m sure one of them will have a personal story (or a story from a friend of a friend) about doing just that.
Without first growing the succulent in dry soil with LECA and then switching it to a semi-hydroponics setup though, you won’t likely see any success.
Even still, that growing method is mostly recommended for cuttings, not fully grown succulents.
The thing about succulents is they don’t need much water. They keep what hydration they require in their bulbous leaves and then slowly absorb the water over time as they need it. Growing them in a container of water makes little sense.
While indoor gardeners can have vastly different experiences growing the same plant, especially when it comes to growing plants using LECA, one type of plant that many gardeners agree doesn’t bode well in LECA is the fern.
The Boston fern especially tends to produce a lot of headaches when grown semi-hydroponically. The maidenhair fern is another.
What’s the issue? According to many fellow gardeners I’ve spoken with it seems there’s not one issue, but a myriad of them when it comes to ferns grown in LECA.
Even with the proper light and humidity requirements, ferns will often struggle and die when grown using LECA.
Plant dormancy can be a sign that your plant doesn’t like its new environment. Over and over, the ferns I’ve grown with the use of LECA seem to remain stunted. Even after several months in LECA, my ferns failed to produce any new leaves.
It does appear that using distilled water or rainwater might help a fern excel in LECA (and in general), but just from my own harrowing experiences, I would say, skip growing the ferns in your LECA, unless you’re up for the challenge.
String of Pearls
The succulent vine plant known as the string of pearls is yet another plant that should probably stay away from semi-hydroponics.
The primary reason for that is the string of pearls needs water seldomly. Just how seldom should you water your string of pearls?
Because the string of pearls like to be watered only after their soil has had a chance to completely dry out between being watered, you can often go 1 to 2 weeks between waterings.
Each pearl-like growth on the string of pearls vines can hold onto water and dispense it to the rest of the plant as needed.
Its sensitivity to overwatering combined with the fragility of the string of pearls means that you need to baby this houseplant.
Like I recommended for the other succulent on this list, the elephant bush, you might have more success if you grow your string of pearls in healthy potting soil.
I’ve had the best luck growing all types of pothos over the years, and while they can grow in LECA, I wouldn’t say that choosing LECA to grow your pothos in would be doing your pothos any favors.
Whether yours is a variegated pothos, a young pothos, or you’re propagating a pothos in LECA, I’ve found that pothos just prefer to be grown hydroponically or in traditional potting soil situations.
Even if your pothos is a little thing right now because it’s young, I still wouldn’t recommend semi-hydroponics.
When grown in water, the pothos can develop a condition called wet feet. As the name alludes, wet feet cause the plant’s roots to become soaked in water.
Wet feet can be the precursor to root rot. If you notice something is wrong with your pothos and fix it while its “feet” are still wet, then you can likely save it.
By the time the plant’s condition progresses to root rot, it’s hard to say if it’s survivable.
How about an edible houseplant? Growing potatoes indoors is one of life’s simple pleasures. You’ll love watching your spuds grow week by week until you can harvest them.
Well, if you can harvest them.
Potatoes can grow in a semi-hydroponic environment, but it’s not feasible, here’s why:
Soil is part of the maturation process for potatoes, and that includes sweet potatoes as well. Also, due to the large roots of a growing potato, you’d need a huge container with plenty of LECA balls to support your burgeoning spud.
I touched on earlier how LECA balls are expensive, so you’d be shelling out a lot of money to grow potatoes in water.
Unless you’re growing potatoes in LECA for the novelty factor, which is perfectly fine, It’s much more convenient and cost-effective to grow your potatoes in soil.
Fresh corn on the cob is a side dish for every grilled summer meal, which has inspired you to grow your own corn.
Before you start filling a container with LECA balls, you might want to think twice about growing corn semi-hydroponically.
Like when growing potatoes, you’d need a huge semi-hydroponics system to support your corn plants. This is again very costly.
If you could only grow corn in jars or vases of water, then you’d have to plant one ear at a time, which is hardly enough to feed all the guests at your summer barbeque. Soil suits corn better.
How Do You Know Whether Your Plant Will Do Well in LECA?
Semi-hydroponics for plants can work, but it requires some understanding of the type of plant you’re dealing with. If your plant lacks these 3 main traits, I would strongly recommend not growing it in LECA.
Plants that Grow Roots Quickly
Speedy root development is key in a successful semi-hydroponics transition.
How fast a plant lays down roots depends on the species. A healthy plant will always grow roots faster than an unhealthy one, so before you make the move to LECA, ensure your plant is in tip-top shape.
Plants that Bounce Back Fast
Most houseplants don’t like being moved, so the stress of that can affect your plant’s health as you switch them from soil to LECA can lead to a rocky start in the new setup.
Since you need to rinse your plant off to remove its soil before putting it in its LECA-filled container, houseplants that don’t like being handled will be even more stressed.
If your houseplant has proven that it can handle stress well and bounce back quickly (in a day or several), then you can try LECA. For plants that don’t recover from stress as fast, it’s not worth putting them through all that strain just to grow them semi-hydroponically.
Plants Like Being Submerged in Water
Here’s the big one. If your houseplant doesn’t need much water because it can sustain itself on little (such as succulents), or standing water causes the plant severe harm, then it’s not a candidate for semi-hydroponics.
Yes, LECA balls absorb some water. And yes, LECA can prevent the damage of overwatering, to an extent. Even still, standing water is standing water, and there’s a lot of standing water involved in a semi-hydroponic systems.