You’d imagine that the forgiving ZZ perennial would be a beginner’s dream. Yet, many people lose patience waiting for those shiny leaflets to reach their full potential and end up wondering: why is my ZZ plant not growing fast enough?
The ZZ (Zamioculcas zamiifolia) is a slow grower by nature, but unfavorable conditions can slow down the plant’s development even more.
What growth rates are normal, and how can you improve the growing conditions to speed up the process? That’s what this article digs into!
Before you get too worked up about your plant’s poor growth, let’s just modulate our expectations.
So, the ZZ plant is a slow grower, but how slow exactly?
It can reach 3 feet, and that doesn’t sound too shabby. However, the RHS says it’ll take 2–5 years to get to that height, even if the conditions are favorable!
In most cases, plant parents don’t even notice the growth right away because the ZZ just gathers energy in potato-like rhizomes for a while before the shoots emerge from the potting mix.
It’s also normal for the process to slow down during the winter, which can make it seem like there’s something wrong with the plant.
All in all, if a whole growing season goes by and your ZZ has gained only 6 inches, then you’ve got nothing to worry about.
Now, if the growth rate is slower than that, we’d say it’s time to intervene.
If you’re still reading at this point, it means your ZZ plant’s growth is below the expected timeframe, and you’d like to do something about it.
More often than not, we can trace back stunted growth to a flawed care routine. That could be anything from using the wrong pot size to exposing the plant to cold drafts.
Don’t feel bad; there’s still hope, but only if you identify the mistake that’s holding your houseplant back.
Let’s dive in and see what parts of the care routine you can tweak around to help boost a ZZ plant’s growth:
Did you know that the ZZ is also called the Zanzibar Gem? That’s because (yes, you guessed it) it’s native to Zanzibar.
It also grows in other East African countries, like Tanzania. However, the Zanzibar Gem name stuck for some reason.
The takeaway from this nickname is that the plant is as tropical as it gets and won’t put up with extreme cold. In fact, its growth will be stunted once the temperature drops below 50°F.
So, the first step in boosting the growth rate is troubleshooting the common temperature-related problems. Here are some questions to help you out:
- Is your ZZ sheltered from cold drafts, or is it in front of an air conditioning vent?
- If you’re planting the ZZ outdoors, are you in USDA zones 10B–12?
- If it’s growing indoors, is the temperature between 65°F and 90°F year-round? (The warmer it is, the better!)
Now, we know that 90°F indoors might be a bit too toasty for your liking. So, we’d recommend trying to raise that thermostat as far as you’re comfortable.
You can also relocate the pot to a warm spot in your home. That said, putting it near a radiator isn’t a good idea because it’ll dry up quickly.
ZZ plants aren’t particularly fussy about light and will survive even in dim spots—so much so that some people claim that they can grow them in closets!
Maybe that would work for some people, but just because the plant hasn’t died yet doesn’t mean it’ll grow at a normal rate in low-light conditions.
To get the best results, you’ll want to give your tropical houseplant around 6 hours of bright (but indirect) sunlight daily.
If the ZZ is growing in a windowless office, then fluorescent lights will have to do. Meanwhile, a north-facing window is perfect for the job if you’re growing the ZZ plant at home!
If a south-facing window is your only option, use sheer curtains over it to reduce the light intensity. Alternatively, you can move the pot towards the center of the room and aim for early morning and late day sun.
Keep in mind that direct sun won’t only scorch the leaves, but it could also suck up moisture from the potting mixture.
ZZ plants are often recommended for people who tend to underwater their plants. That’s because they’re super drought-tolerant, thanks to their rhizomes that store water.
For the most part, the plant handles drought like a champ and survives, shedding only the occasional leaf.
However, this tolerance has its limits and drawbacks. Stunted growth is one of them.
That’s because leaving the plant thirsty for long periods fools it into thinking that it’s in the dry season and that it needs to preserve resources.
You’ll know you’re criminally underwatering the plant if you spot wrinkled foliage or wilting. In this case, you can rebalance your watering schedule by going for a full soak every 2–3 weeks (or whenever the top part of the soil feels dry) and draining the excess.
Of course, to get proper drainage, you’ll want to use free-draining soil mixes and pots with bottom holes.
You’ve probably been told to give the ZZ plant some vertical clearance to leave room for the leaves to grow, but did you know that the roots, too, need space?
When the plant overgrows the pot, the roots will get bound. Then, the growth will be throttled because the root system can no longer transport an adequate amount of water and nutrients to the foliage.
That would kill some sensitive plants but not the Zanzibar Gem! It’ll survive but at a slower growth rate.
You’ll know that your precious ZZ is pot-bound if you see some rhizomes bulging from the sides. Once you see those pumps, it’s time to repot to a larger container.
The catch here is that you don’t want to go too large, either. That would just require a lot of water and leave the soil soggy.
Instead, try to get a pot that’s larger than the current one but still not more than a third wider than the plant’s root system.
We’d like to note that managing your expectations is vital here, too. You won’t see a sudden boost in growth after the repotting since the roots will need a while to spread first.
Well-drained sand or clay soil works well for ZZ plants, but you also need some nutrition.
If you’ve had your ZZ for a while, odds are, the soil is depleted. That translates to fewer nutrients to support the growing foliage.
This problem is easy to fix, though.
Grab a balanced (4-5-4 or 5-5-5) water-soluble fertilizer and dilute it to half the strength. Then, use it once or twice during the growing season (spring and summer) and call it a day.
If you use a 10-10-10 liquid fertilizer, you might need to dilute it to a quarter. Otherwise, it could be too strong, and you’ll risk burning the ZZ’s root system.
ZZ plants are forgiving and virtually impossible to kill, which is probably why they get the short end of the stick so often.
Sure, they’re already slow-growers, but you aren’t doing them any favors by leaving them pot-bound or neglecting their temperature needs. Underwatering and underfeeding will also stunt a ZZ that would have been perfectly fine otherwise.
So, make sure to balance the care routine, then all that’s left is to embrace the plant’s normal growth rate!
Growing up with a mom who filled her home (inside and out) with all sorts of plants, Lisa got her start in gardening at a young age. Living now on her own with a home and yard full of plants (including an indoor greenhouse), she shares all the gardening tips she’s gained over the years.