After 30+ years in the houseplant hobby I love how much more we can get now for our indoor plants. Things like self-watering pots. Once a DIY project, now we can get pre-made perfect-fit self-watering pot kits, wick included.
Not to mention the range of self-watering substrates is fanastic now. Leca, Pon, my favourite Bio Leaf for Moisture Lovers (which wicks like a dream).
But one thing you can't so readily buy is wicks... until you know what everyone else uses. Then you'll have no problem finding wicks. There are so many options. BUT there is an art to picking the right wick for the substrate, for the plant, and for your peace of mind....
To save you the time and money, here's my list from over the years of trying different wicks, including which wick types I've found work best in different set-ups for different plants.
And an important WARNING for what to do EVERY TIME time you buy new wicks (even if it's the same wick material you've bought before)...
Cotton wicks![]()
Yes, I know this is what you get free with most self-watering pots, and for good reason (they wick super well), and it's super easy to find more (macrame cord is usually 100% cotton for example) - BUT I'd take buying cotton cord off your wick list altogether for self-watering pots.
Cotton is the most absorbant, right to the core, so it gets a big tick if you're finding a chunkier semi-hydro substrate like leca isn't staying wet enough.
BUT cotton is a natural plant fibre. That means it will break down over time, sped up by being in constant contact with water. As it breaks down, bad bacteria, harmful fungi and other microbes can set up home, breeding root rot and other bad news for your plants.
A note if you're wanting a wick for growing something you're going to eat later, like micro-greens, is that cotton might be your best choice if you're worried about microplastics.
Mason line
This gets a big YES from me. You want raw, untreated, nylon mason line specifically. Made by loads of different companies and easy to find both online and at hardware stores.
If the mason line says it's bonded or coated that's a sign it's NOT raw. If it's been coated or treated with something to reduce moisture and mildew, it tells you it won't wick as well.
If you prefer a white wick for aesthetic reasons, and can only find mason line in bright colours, have a look for nylon twine string instead, below (mason line is one type of nylon twine).
Mason line tends to shift water well but not absorb it right to the core, so doesn't wick up as much water as acrylic or cotton. A good option if you're finding your substrate's staying too wet.
Acrylic yarn
NOT wool or natural yarn. Acrylic or synthetic yarn is another big YES from me. I especially like it for my little guys like my African Violets. I use 4 ply acrylic yarn specifically, but by all means experiment. Just note the important WARNING at the end.
I especially like yarn when used with Bio Leaf for Moisture Lovers mix as the substrate. They make a great combo in my set-up for keeping my AV's at an ideal moisture level. Although it doesn't wick water quite as well as a cotton wick, it's still at the higher end of the range for wick ability.
Wicking rope
This one gets a maybe from me. Some companies sell 'wicking rope' or 'wicking cord' but just because the name it seem an obvious choice, what isn't always obvious is what it's made of.
ALWAYS research what a generic 'wicking rope' is made of before buying. I'd avoid the natural cotton or cotton blend ones and look for nylon or synthetic. It will also usually come in a range of thicknesses, with around 3mm to 6mm a popular range to use for wicks.
Braided nylon cord
Mason line is one type of braided nylon cord, sometimes called braided nylon rope, but a search for 'braided nylon cord' should find you lots of matches.
Braided nylon cord also tends to come in a wider range of thicknesses compared to mason line and is easier to find in white. I'd look at 2mm at the minimum thickness but 3mm to 6mm is a pretty common range for self-watering wicks.
I'd give the same advice though as mason line. You want to look for something that mentions it's raw or uncoated. If you're unsure - or even if you're sure it is not coated - I'd still follow the WARNING at the end.
Both braided nylon cord and mason line are more in the medium to low end of the scale for how much water they wick depending on size. Good options if cotton or yarn is keeping your substrate too wet.
Microfibre
I LOVE microfibre wicks for leca in particular, but because you can cut it to different thicknesses (depending on where you find your microfibre), you can adjust it to suit the substrate. A really good all-rounder for semi-hydro including Pon.
My favourite place to find microfibre strips is replacement microfibre mop heads (you should have luck at your local hardware store). You can also buy 'microfibre rope' online or DIY your own from microfibre fabric available at stores like Spotlight.
Paracord (parachute cord)
Paracord is usually made of nylon but you can get polyester paracord also. It's available in different thicknesses also. It's close but I've found polyster paracord wicks better for me than nylon. I'd go for between 3mm and 6mm thickness. I tend to get the 4mm myself. In general I find paracord wicks down near the lower end of the scale.
Anything polypropylene
This one gets a NO from me. Check the fine print for what your rope or cord is made of. Polypropylene is NOT the same as polyethylene or polyester.
Those last two can make great wick materials. Polypropylene however is hydrophobic (meaning it repels water), and annoyingly, it also floats. I only made that mistake once.
Another reason to always follow the WARNING below...
WARNING before using ANY wick
Yes, even if the wick came WITH your self-watering pot, I'd still do this important step BEFORE you pot up your plant.
First, soak the wick (you don't want to pot up with a dry wick or dry substrate). Next, put one end of the wick in a container of water, the other in an empty container. Now check it actually wicks first!
Finding out AFTER you've potted up your plant, that your wick is a dud, is NOT something I'd recommend. Ask me how I know.
I've had some weird wick surprises over the years. Every so often - even when I buy the same brand, same everything that I've bought before - they like to surprise me and NOT WICK or wick so poorly it's pointless.
Learn more...
Curious about all-things self-watering? Head over to the ultimate beginner's guide to self-watering in leca and pon > next and continue learning.
ABOUT THE AUTHOR: Anna is the owner of plant store Love That Leaf which specialises in products and advice for indoor plants. She is also the resident indoor plants writer for NZ Gardener magazine. Her houseplant care articles appear in print in magazines in-stores NZ-wide, and online on Stuff, The Post, NineHoney and more.