Oyas
The olla regulates water flow according to each plant's needs
We love our plants. We talk to them, move them around hunting for 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. The result: roots that suffer, leaves that turn yellow, 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 plant in the compost — is based on a disarmingly simple physical principle: the natural porosity of terracotta lets water seep in slowly, at the exact 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 away. Each oya is hand-shaped, 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 crystal clear — and that's exactly what makes it brilliant. A terracotta oya is a reservoir with naturally microporous walls. When you fill it with water and push it into the compost, 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 nicely moist, the flow slows down on its own. If the soil dries out, diffusion speeds up. The plant regulates — not you. And honestly, that changes everything.
The earliest traces of this irrigation system date back over 4,000 years, in 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 handcrafted oyas apart from a homemade system
If you've ever searched "DIY oya" online, you've probably come across the famous tutorial with two terracotta pots glued together with silicone sealant. We won't pretend: the idea is clever. And in a pinch, it can do the job. But there's quite a gap between a weekend DIY and an oya built 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 humidity cycles. And visually… let's just say it doesn't exactly look dreamy in a nice planter.
Pepin oyas are a different approach altogether. Each piece is hand-shaped, using terracotta selected specifically for its consistent porosity. The result: steady, reliable diffusion, week after week. The neck is designed to sit elegantly above the pot, serving both as a visual indicator for refilling and as a decorative element.
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 every piece is unique (handcraft sees to that), your oya won't look like any other.
How long the watering lasts and how to know it's working
THE question everyone asks — and rightly so. On average, an olla gives you about 1 week of autonomy. But it depends on a few 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 touching a thing.
To check everything is working, it's simple: look at the water level in the neck. If it's dropping, the oya is diffusing. You can also touch the compost around the oya — it should feel 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 gap stops capillary action from working). Then check whether limescale has built up on the terracotta, which can reduce porosity.
oyas that truly fit your interior
What often surprises people the first time is that the neck of the oya sticks out above the pot. And that's entirely intentional. At Pepin, the stance is clear: the oya is part of the decor. That little coloured neck peeking out from the foliage — it's 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 — effortlessly.
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" one for end of the school year, also show that the oya makes a genuinely 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 rate 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: in the first few days, it can be useful to keep an eye on the water level to understand your plant's consumption rhythm. And 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. Then push it into the compost of your pot, fill the neck with water, and that's all there is to 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 top up 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", meaning pot or cooking pot. Both terms refer to a porous terracotta reservoir used for capillary irrigation. At Pepin, we use the term "olla".
How do I look after my oya?
Rinse the olla with clean water from time to time to remove any mineral deposits. And that's it!
At its heart, an oya is an object of rare simplicity. A principle thousands of years old, a living material worked by hand, and a concrete result: better-hydrated plants, effortlessly, stress-free. All in an object that's as much a pleasure to look at as it is to use. If you're looking for a way to make watering your plants more peaceful — and more beautiful — take a moment to browse the different colours and sizes. There's definitely an oya that suits your interior and your plants.