202: How to Build a Sustainable Wardrobe with Julia Dietmar, Co-Founder of OpenWardrobe.
In this episode, we chat with Julia Dietmar, Co-Founder and CEO of OpenWardrobe, a platform helping people use what they already own and make smarter fashion choices. Julia shares how a messy closet sparked her sustainability journey, how OpenWardrobe helps digitize closets and plan outfits with AI, and why the most sustainable choice is wearing what you already have. We also explore her Style Blueprint approach and the real impact of fashion’s overproduction and waste.In this episode, we talk to Julia K. Dietmar, Co-Founder & CEO of OpenWardrobe, a platform helping people use what they already own, plan outfits with AI, and plug into circular options like repairs, alterations, and resale.
During this episode we look at how a messy closet sparked Julia’s sustainability journey and unpacks what OpenWardrobe actually does—digitize your closet, help you plan outfits, spark AI styling ideas, and plug you into repairs, alterations, and resale, while making the case that the “most sustainable” choice is usually wearing what you already own (cost-per-wear). We share practical ways to buy less and love your wardrobe more, walk through Style Blueprint 101 (your colors, body shape/silhouettes, and style personality), and get real about fashion’s overproduction problem—from “52 seasons” to landfill stats and water impacts.
Timestamps to relevant points within the episode, use this format:
[00:00]-Intro
[02:20] – Welcome to Mama Earth Talk + episode setup
[03:17] – Guest intro: Julia K. Dietmar (OpenWardrobe)
[04:36] – Julia’s sustainable journey (personal & professional)
[05:50] – What is OpenWardrobe? Tools for mindful dressing
[06:52] – “I’d never have paired these!”—AI outfit ideas feedback
[11:00] – Empowering consumers vs. “just buy sustainable brands”
[12:40] – What is sustainable fashion? (The “30 wears” idea)
[14:34] – Platform or movement? Why OW is a toolkit first
[16:11] – Buying less without trying: versatility kills the urge to shop
[21:28] – Style tip: don’t imitate—dress for how you want to feel
[23:25] – Resale & repairs: Poshmark integrations; US alterations/repairs
[27:40] – Stats you can use: cost-per-wear; carbon footprint (coming later)
[29:45] – From 2 to 52 seasons: the overproduction problem
[31:55] – Landfill reality; existing clothes could dress six generations
[33:12] – One T-shirt = ~700 gallons of water perspective
[37:01] – Personal shifts: buying less; avoiding plastic packaging
[37:01] – Style Blueprint deep-dive: colors, silhouettes, personality
[41:33] – Brand lists by style personality & learning resources
[42:56] – Final 5 begins
[43:20] – Hope for the Planet
[43:35] – Eco Tip of the Week
[43:53] – A sustainability fact that lands in any room
[44:30] – Where to find Julia & OpenWardrobe
Links from the episodes:
Bonus video: Wardrobe + Blueprint walk-through
30% off the Style Blueprint with code MAMMAEARTH (all caps) at checkout on OpenWardrobe.
Where can people find our guest?
Key Takeaways:
- Use what you own.The “most sustainable” piece is the one already in your closet; aim for ~30 wearsper item.
- Plan > impulse.Digitizing your closet and pre-planning outfits slashes returns, unused buys, and clutter.
- Versatility = fewer purchases.Pairing pieces in new ways reduces the urge to “add another top.”
- Measure what matters.Cost-per-wearand category mix reveal where your money goes vs. what you actually wear.
- Make the most of the loop.Repairs, alterations, and resale extend life, fit, and value.
- Style Blueprint wins.Knowing yourcolors, silhouettes, and personalitymakes every future purchase smarter.
- Perspective resets habits.One T-shirt uses ~700 gallonsof water; globally,11.3M tonsof textiles hit landfills annually.
About the author, Mariska
Hi, I’m Mariska – podcast host, artist, sustainability advocate and consultant, and storyteller driven by a deep passion for our planet. Sustainability isn’t just a topic I discuss; it’s a way of life I embody through my work, actions, and everyday choices.
My journey began several years ago when I started experimenting with trash as a medium in my artwork. What began as creative curiosity quickly turned into a deep dive into the environmental impact of waste. That curiosity expanded into a broader connection with nature—including a life-changing trek to the summit of Mount Kilimanjaro, where I found both clarity and purpose. It was there that I made the decision to leave the corporate world behind and commit fully to environmental work.
In 2018, I took that message public in the UAE by wearing every piece of trash I generated for 30 days. The result—65 kilograms of waste—sparked national conversations around sustainability and waste reduction. That bold experiment also became the catalyst for my podcast, Mama Earth Talk, where I’ve since connected with global thought leaders to explore sustainability and inspire meaningful action.
Over the years, I’ve collaborated with organizations such as Nespresso, Costa, and Dubai International Airport to implement practical and impactful environmental solutions. From optimizing waste management systems to leading awareness campaigns, I specialize in designing strategies that create real, lasting change.
My artwork—blending environmental advocacy with creative expression—has been collected by public figures including comedian Trevor Noah, environmentalist Adrian Grenier, entrepreneur Gary Vaynerchuk, radio host Kris Fade, Grammy Award-winning DJ Black Coffee, and NBA player Mason Plumlee. Through public speaking, podcasting, and art, I aim to inspire individuals and organizations to rethink their relationship with the environment.
With over a decade of international experience in design and project management across Australia, South Africa, the UK, India, and the UAE, I bring a unique mix of creativity and strategic insight to sustainability challenges. My global perspective allows me to collaborate across cultures, drive innovation, and empower others to make a meaningful impact.
As a lifelong learner and passionate advocate, I focus on practical, holistic solutions to environmental challenges—guided by systems thinking and a deep commitment to action. I hold a BA in Design, a postgraduate degree in Environmental Science, and a Master’s in Sustainable Design.