Oyas
The olla regulates water flow according to each plant's needs
We love our plants. We talk to them, move them around to find THE perfect light, give them little names. And then… we forget to water them for ten days. Or, gripped by guilt, we drown them in half a litre of water on a Sunday evening. Result: roots under stress, yellowing leaves, and that little voice whispering "I'm just not a plant person".
Good news: the problem isn't you. It's the method. And the solution has existed for over 4,000 years. The oya, that small terracotta reservoir you push into the soil, is based on a disarmingly simple physical principle: the natural porosity of terracotta lets water seep in slowly, at exactly the pace the plant needs. No technology, no batteries, no app. Just terracotta and physics.
At Pepin, we took this ancestral object and turned it into something you want to show off, not hide. Each oya is shaped by hand, with colours, patterns and finishes that make it a genuine decorative object. Because self-watering for your plants can also be beautiful.
How an oya works (and why it's so effective)
The principle is beautifully simple — which is exactly what makes it brilliant. An oya made from terracotta is a reservoir with naturally microporous walls. When you fill it with water and push it into the soil, the water passes through the walls by capillary action: that physical phenomenon where water naturally migrates from a moist environment towards a drier one.
In practice, the plant "draws" the water it needs, when it needs it. If the soil around the oya is already nice and moist, the flow slows down on its own. If the soil dries out, diffusion speeds up. It's the plant that regulates, not you. And honestly, that changes everything.
The earliest traces of this irrigation system date back over 4,000 years, in the arid regions of China and North Africa. Entire civilisations grew crops thanks to terracotta jars buried in the ground. The principle hasn't changed. We've simply adapted it for your indoor pots.
What sets artisan oyas apart from a homemade system
If you've ever typed "make an oya" into a search engine, you've probably come across the famous tutorial of two terracotta pots glued together with silicone sealant. Let's be honest: the idea is clever. And as a quick fix, it can do the job. But there's a world of difference between a Sunday DIY project and an oya designed to last.
The first issue with DIY is porosity. A standard garden centre pot isn't designed to diffuse water evenly. Some areas let too much water through, others not enough. The seal between the two pots often ends up giving way, especially with moisture cycles. And visually... let's just say it doesn't exactly look dreamy in a nice plant pot cover.
Pepin oyas are a different approach entirely. Each piece is shaped by hand, using a terracotta selected specifically for its consistent porosity. The result: steady, reliable diffusion, week after week. The neck is designed to sit elegantly above the rim of the pot — it works both as a visual guide for refilling and as a decorative detail.
And maybe that's the real turning point: with Pepin, the oya is no longer a utilitarian object you hide under the leaves. It's an accessory you actually want to show off. And since each piece is unique (that's the beauty of craft), your oya won't look like anyone else's.
How long the watering lasts and how to know it's working
That's THE question everyone asks, and understandably so. On average, an olla provides about 1 week of autonomy. But it depends on several factors: the size of the oya, the volume of the pot, the type of plant, the season, sun exposure, room temperature… In summer, it goes faster. In winter, an oya can easily last 10 days without you needing to do a thing.
To check everything's going well, it's simple: look at the water level in the neck. If it's going down, the oya is diffusing. You can also feel the soil around the oya — it should be slightly moist, without being waterlogged. That's a good sign.
If the water level doesn't move at all after several days, there are two things to check. First, make sure the soil is in good contact with the walls of the oya (an air pocket stops capillary action from working). Then, check whether limescale has built up on the terracotta, which can reduce porosity.
oyas that truly fit into your interior
What often surprises people the first time is that the neck of the oya sticks out above the pot. And that's completely intentional. At Pepin, the design choice is clear: the oya is part of the décor. That little colourful neck emerging from the foliage is like an accessory for your plants.
On a windowsill with three mini oyas lined up in pots of different sizes, it creates a cohesive, living arrangement. In a large pot with a monstera, a classic oya adds that little detail that catches the eye. On a desk shelf, it's the kind of touch that makes a space feel warmer without any effort.
The heart or leopard olla are exactly the kind of pieces that become conversation starters. "What's that adorable thing in your pot?" — and suddenly you're explaining capillary action to your guests. The limited editions, like the "Merci" for end of school year, also show that the oya makes a truly thoughtful gift: useful, original, and beautiful. Not another mug or bunch of cut flowers.
Frequently asked questions about oyas
Are oyas really effective?
Yes, it works on a very real physical principle: the porosity of terracotta combined with capillary action. Water passes through the walls at a pace dictated by the plant's needs. The only condition for it to work well: the soil must be in direct contact with the walls of the oya.
We'd rather be upfront with you. oyas do have a few limitations worth knowing about: in the first few days, it can be helpful to keep an eye on the water level to understand your plant's consumption rhythm. Also, for very small plants in pots under 8 cm, even our mini ollas can be oversized. In every other case, they do exactly what we ask of them.
How do I fill and use an oya?
Before first use, soak your oya in water for at least 30 minutes — this saturates the terracotta with water. Then push it into the soil of your pot, fill the neck with water, and that's it. When the level drops, just top it up.
How long does an oya hold water?
Expect around a week of autonomy depending on the plant and the season. In summer, you might refill twice. In winter, some oyas last ten days or more. You'll quickly find your rhythm.
What's the difference between an olla and an oya?
None at all — it's the same object. "Oya" comes from the Spanish "olla", which means pot or cooking pot. Both terms refer to a porous terracotta reservoir used for capillary irrigation.
How do I care for my oya?
Rinse the olla with clean water from time to time to remove any mineral deposits. And that's it!
At its core, an oya is a remarkably simple object. A principle thousands of years old, a living material shaped by hand, and a tangible result: better-hydrated plants, effortlessly, stress-free. All in an object that's just as enjoyable to look at as it is to use. If you're looking for a way to make watering your plants calmer — and more beautiful — take the time to browse the different colours and sizes. There's bound to be an oya that suits your interior and your plants.