Back when I was new to house plant care, I had no aspirations to actually grow my plants. My end game was simply to keep the damn things alive.
But then it happened. New leaves were unfurling, roots were starting to peep through the bottom of pots…it was this exact moment when plants began to take over my life (and my house).
It can be frustrating when your plant just won’t grow. You think you’re doing everything right, but you’re not seeing any growth.
This post will help you troubleshoot why your plant isn’t growing. It can be a process of trial and error working out exactly what the culprit is, but I recommend you just experiment.
Reasons your plant isn’t growing:
- It’s not getting enough light
- It’s not getting enough water
- It’s getting too much water
- It’s not getting enough humidity
- It needs cleaning
- It needs fertilising
- It’s being over fertilised
- It’s rootbound
- It needs a smaller pot
It’s weird how these things always seem to come in 9s…9 ways to increase the humidity in your home, 9 signs your plant needs water…I don’t do it on purpose, I swear.
Your plant isn’t getting enough light
Plants need light. They use it to create energy. Photosynthesis is a whole big thing for plants.
Just because you don’t have massive windows doesn’t mean you don’t have enough light to keep plants – you just need to keep plants that naturally live in lower light conditions, such as on the rainforest floor.
Keep in mind that plants that live close the forest floor often require pretty high humidity. If you have lower light and low humidity conditions, go for a ZZ plant. They’re super chill guys.
If you want to increase the light in your home, check out this article.
Your plant isn’t getting enough water
I linked to the post above about how to know if your plant is dehydrated, so check that out if you’re unsure.
Sure, plants die more quickly if being overwatered, but they still will die if you underwater them. Even cacti and succulents.
To check if your plant is dry, either check the soil with a moisture metre, or just stick your finger into the soil. This is a less technical way of doing it, and not as accurate as you might think.
Once you’ve gotten more acquainted with your plants you’ll be able to tell if they’re thirsty just by how light their pot is.
Your plant is getting too much water
If your plant looks sad, limp, and yellow, then that may be a sign that you’re overwatering it.
Very few of my plants need watering more than every couple of weeks, and I have my fair share of moisture-loving plants like calathea.
How often you water your plants depends a lot of where you live and the time of year, which is why I suggest that plant noobs get a moisture meter. I have a whole post on how often you need to water your plants here if you’re unsure.
Your plant isn’t getting enough humidity
If your plant is getting brown tips, or brown leaf edges, this is likely a sign that your plant isn’t getting enough humidity. You’ve probably read about how misting plants can increase their humidity, but realistically, it’s a waste of your time.
If you have a lot of plants it’s probably worth investing a humidifier, although this post goes through various other ways you can increase the ambient humidity in your home.
Nothing will replace a humidifier though.
Your plant is too dusty
Yeah, I’m as guilty as the next person for not being the most vigilant when it comes to cleaning my plants, but it makes a massive difference, especially if you’ve not got the best light.
All my plant cleaning wisdom is here.
I once read an article explaining why talking to your plant helps them grow, and one lady who was SURE her plants benefited from her speaking to them explained that she spoke to her plant every week when she cleaned his leaves.
Whilst I’m not saying that her yucca didn’t love her voice, I definitely thing the regular cleaning and general attention is what caused the yucca to thrive.
Plants attract dust like nothing else on earth except possibly glass shelving.
This is the very reason I went for the Ikea Fjallbo rather than the more traditional plant parent choice of the Vittsjo. How much time are y’all spending dusting??
The problem with dusty plants is that it inhibits both their ability to transpire (it can block their stomata) and their ability to photosynthesise (the dust blocks out the light).
So yeah, dust your damn plants.
Your plant needs fertiliser
If you have a peaky-looking slow-growing plant that hasn’t been repotted for a while, it could need some fertiliser.
Whilst plants get the majority of their energy from the sun, they get additional nutrients from the soil they live in.
If you’re new to fertilising, I have an article on it here.
I personally use a seaweed fertiliser, because it’s pretty natural, and I won’t use fish emulsion because I’m vegan. When your plants need watering, water them normally, then follow with some diluted (half the strength of whatever the manufacturer recommends) fertiliser.
If fertiliser frightens you, and your plant isn’t ready for repotting, add some worm castings to the top of the soil and mix them in with your fingers. It adds nutrients and you won’t risk burning delicate roots.
Your plant is getting too much fertiliser
Over fertilising is common, but quite difficult to diagnose. It can poison your plant, so look for a crust forming on the surface of the soil and yellowing leaves as well as lack of growth.
Like i said in the point above, worm castings are a great place to start with a gentle fertiliser.
If you really want to provide a great environment for your plant, then consider switching its potting mix. If your plant is doing ok, DON’T repot it for the sake of it.
Wait for it to out grow it’s pot and then make it a custom potting mix, rather than just using house plant potting mix. I have a recipe at the bottom of this post.
A homemade mix encourages strong roots, increase soil aeration, and is more environmentally friendly because it’s peat-free.
Wow, it really sounds like a selling potting mix, doesn’t it? I’m not, I swear.
ANYWAY my recipe contains worm castings, rather than those suspicious blue pebbles that bought potting mix does.
This whole repotting business leads us neatly to our final couple of issues: pot size
Your plant is root bound
If your plant is root bound, not only is it not able to grow roots as effectively anymore, but it’ll run out of water and nutrients much quicker because there won’t be enough soil to sustain the root ball.
If you’re new to repotting house plants, give this article a read.
I favour not disturbing the root ball over easing out all the old soil, but that’s probably because I’m both lazy and clumsy.
If your plant is very root bound then very gently ease the roots apart so that they can grow out into the new potting mix.
Your plant needs a smaller pot
When you do need to repot your plant, don’t be tempted to get the biggest pot you can find. Increase the pot size by a couple of inches.
I’ve nearly killed a few plants by over potting them. When there’s far more potting mix mix than the plant can possibly need, you run the risk of root rot, because the soil will hold on to water for a lot longer. This is especially true if you’re using house plant potting mix.
If you can’t get hold of the ingredients to make your own potting mix, or you can’t afford them (it can be cheaper in the long run to DIY potting mix, but you’ll need about £40 for the initial ingredients), then at the very least add some more drainage to your soil.
Adding perlite or orchid bark is really great for adding drainage. It absorbs water, so the mix is moist, rather than a muddy goop.
So there we go, the main reasons that your plants are thriving. I would definitely start by assessing the light your plant has and your watering regime before hiking up the humidity or repotting.
These two issues are the ones that are most crucial to get right and your plant will turn around quickly once you have it’s light and hydration correct.
I would add one more very important line to your list. After about a year, all-purpose potting mixes break down and become “sour”. For the first several months, your plant will simply stop growing. At some point though, it will go into decline. So the point is that if you’re using regular potting mix for your plants, you need to repot every year to 18 months to keep it fresh. An alternative to that is to use coir, which is processed coconut husk. It never really goes bad, so you don’t have to worry about repotting until your plant outgrows its pot. The caveat to this is that you need to regularly fertilize because it contains no nutrients whatsoever.
Ew, I didn’t know it went sour, just that it gets depleted of nutrients. I find pure coir a bit heavy, but with some added bark and worm castings for fertiliser it’s a great option