Haworthia Cooperi is a great succulent for indoors. It’s fairly easy to grow and if you’ve got a bright spot out of direct sun on a windowsill then it’ll be quite happy. Plus, they’re slow growers so you won’t need to worry about it outgrowing its pot for quite a while.
|Real Name||Haworthia Cooperi|
|Common Name||Star Window Plant, Cushion Aloe, Window Haworthia|
|Light||Bright indirect light.|
|Water||Let the soil dry completely, then, water deeply.|
|Temperature||Warm days and cool nights|
|Dormancy||Summer and Winter|
|Soil||Quick draining succulent soil.|
|Flowers||Small white flowers on long stems|
In nature, Haworthia grows in the shade of rocks so they don’t love a lot of full sun. Indoors, pick a spot where it’ll get at least a three or four hours of indirect bright light. Outdoors, pop them somewhere where they’ll get dappled light or bright indirect light. They can usually handle a few hours of direct light a day and morning sun is better than the more intense afternoon sun but keep an eye on them for signs of stress like the leaves taking on a reddish brown appearance. Blushing is a fairly natural reaction in succulents and there’s a lot of debate about whether it harms the plant or not so if you like the reddish tinge then give it more sun and keep a close watch for signs of other problems that could be related to too much sun or heat.
In my experience, if you let a Haworthia Cooperi blush then it’ll still continue to grow but it’ll be much slower than one that’s in bright indirect light.
If the leaves start to turn white or yellow it means it’s getting too much light and if the green colour starts to fade then it’s not getting enough.
Like most succulents, Haworthia Cooperi doesn’t need much water. Overwatering is much harder to correct than underwatering so less is better if you’re not sure. Wait until the soil is completely dry then give it a really deep water until the water flows out of the drainage holes and the soil is saturated through.
Try and avoid getting the leaves wet during watering. It’s better to water in the mornings so that if the leaves do get wet they’ll have time to dry out before the cooler night temperatures hit. Make sure to blow any water that gets in the rosette out of there after watering. Standing water on the leaves can cause rot. Once it gets large it can be tricky to water from the top so you may have to bottom water them for a while until you get it into a bigger pot.
Keep an eye out for signs of underwatering like the leaves starting to wrinkle or shrivel up.
If you notice the leaves are turning yellow or brown or start to get mushy or swell up and look like they’re going to burst then it’s a sign that they’re getting too much water. Wait for the soil to dry out completely before watering again. Most of the time, once a succulent starts to show signs of overwatering in the leaves it means the roots are already having some problems so you might need to get it out of the soil, trim off any rotting roots and leave it to dry for a few days then repot it in fresh soil.
Haworthias seem to love spring and autumn (depending on where you are in the world). Once warmer days and cooler nights set in it’ll start putting on some growth. They’re fairly slow growers so it might take a while to notice but, once you do, start watering them a bit more often and give them a dose of very diluted fertilizer to kick off the growing season.
As Haworthia Cooperi are originally from South Africa they like warm days and cool nights and once it gets too hot or too cold they’ll enter dormancy and stop growing. Don’t fertilise them during dormancy and reduce watering as they won’t need much. If you’re growing them indoors then they might not go dormant at all – if they don’t then keep treating them the way you have been.
When night temperatures reach over 24°C (75°F) the plant will start to go dormant. Mine usually flowers in early spring when it starts warming up and the flowers die off once the warmer summer temperatures kick in. Even though you usually reduce watering during dormancy I’ve found that the warmer temperatures in summer mean the soil dries out much faster so they tend to need watering a little less than in spring but it’s not a dramatic decrease.
If temperatures drop below 4°C (39°F) and your Haworthia is outdoors then it’s time to bring it in because not only will it enter dormancy, it’s at risk of freezing. With winter dormancy, reduce the watering significantly. The soil will take longer to dry out between waterings and seeing as the plant’s not growing it doesn’t need that much water anyway.
There’s a lot of debate about which temperature range works best for these little guys. Mine seem to appreciate warmish days between around 20°C – 25°C (68°F – 77°F) and cooler nights around 10°C – 15°c (50°F – 59°F).
Too much humidity is an issue for Haworthia, especially at night when they appreciate good airflow. Haworthias do most of their work at night by taking in carbon dioxide to use for photosynthesis.
They don’t need much fertilising. I give mine a weak dose at the start of spring when they’re waking up from dormancy and another dose at the start of autumn.
As Haworthia are slow growers they tend to be happy in the same pot for a few years and it’s best to wait until the cluster has filled the pot and there’s almost no soil showing.
I prefer to repot them in early spring just as they’re coming out of dormancy – I’ve heard that in summer the roots near the outside of the pot get killed off by the heat so I like to leave them alone to regrow over autumn.
I’ve found a wide fairly shallow pot works pretty well for these guys – especially if you divide some of the clusters and spread them around the pot. Terracotta or unglazed clay are good choices because they’re porous so it helps the soil dry out faster and more evenly between waterings.
Because Haworthia grows in clusters, division’s the easiet way to propagate them. When you repot them look for any clusters that you can separate off and make sure it has a healthy stem and some roots of its own.
There are some folks out there that have managed to propagate from leaves but it’s fairly rare. The divisions really need some stem or root to grow.
Haworthia Cooperi are pretty resilient little plants and most problems can be fixed if you catch the signs early on.
Leaves Losing their Plumpness
If your Haworthia “leaves” start to look less full and they’ve lost that tight bubbly clump appearance then it could be down to a few things and it can make it a little tricky to know how to treat it. Mine tends to go like that when it’s dormant during the summer or when it needs a water. If it’s dormant then watering it too frequently will cause it to rot and you’ll find that even after watering the leaves don’t plump back up. On the other hand, if it’s under-watered then watering it should get your leaves plumping back up within a few days to a week. Resist the temptation to overwater it! As long as it’s healthy overall then it should bounce back but if you start drowning it with water it’ll start to deteriorate.
IMO one of the best things about Haworthia Cooperi is the lush green leaves. If you notice them looking a bit faded or muted or taking on a whitish tinge then it’s not getting enough light. Full sun can cause problems for them but try upping the light whether that’s choosing a brighter spot or getting them somewhere where they can get a couple of hours of direct light a day. Morning sun is better than afternoon sun as it’s less intense and make sure you let it adjust to the extra light bit by bit over the course of a week or so.
Blushing is pretty normal for most succulents so don’t panic! It’s their natural response to getting a lot of sun and seeing as Haworthias prefer bright indirect light any blushing is a sign that it’s getting a bit too much. However, that doesn’t mean you have to change its light requirements if you like the look of it. As long as it’s just a tinge and you’re not seeing the leaves shrivel up or go brown and dry out the it should be fine. The additional sun will slow the growth down though.
Sickly Looking Translucent Leaves
The classic tell tale signs of overwatering show up on Haworthias. The leaves will start to turn a sickly yellow-y brown colour and look a it translucent and they’ll start to turn to mushy.
If you’re seeing symptoms of overwatering it then you’ll need to dig it up and get rid of any rot on the roots and stem, let it dry out then repot it again. I’ve got a full guide to diagnosing overwatered succulents and there’ll be another one coming up soon that talks about how to save your overwatered succulents.
If your plant isn’t getting enough light it’ll start to stretch out so instead of getting lovely tight little clusters the leaves will be much more spaced out.
Unfortunately, you can’t reverse the process but, you might be able to trim off the leggy growth and root it to create some new plants.