A Landscape Design Company Focused on How You Live
Family Legacy Built Into Every Long Island Landscape
What began in 1976 as one man’s commitment to quality and honesty has grown into a family legacy shaping how Long Island lives outdoors. Every project carries our name, and with it, our promise to listen, plan with intention, and design spaces that feel as livable as they are lasting.
Rooted Here. Designed Here. Built Here.
Long Island isn’t where we are, it’s who we are. From the hills of Huntington to the shores of Sag Harbor, we understand its rhythm, its challenges, and its beauty. That’s why our designs fit so naturally here, crafted for how we Long Islanders live, with balance, comfort, and quiet sophistication.
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The family who designs your project stays with it through completion, and gives back through Make-A-Wish builds and local memorials.
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We don’t just install; we imagine, refine, and craft creative environments that belong to their setting.
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Every plan considers proportion, line, and light to create harmony with the home.
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As a full-service design-build firm, we handle every trade, schedule, and detail—so you don’t have to.
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Five decades of experience across Long Island’s unique terrain and communities.
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We’ve built our reputation on precision, artistry, and respect for every stone, plant, and space we touch.
Where Our Craft Becomes Your Story
“Gary and Adam had great vision and experience which helped when planning one of our biggest projects. I really like how much time they will spend with you planning out everything and offering options. I also appreciated their patience because, let's be honest, we homeowners change our minds a lot! They are trustworthy, reasonable and their crew does excellent and meticulous work.”
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— Alan H., via Google
Our Word, Our Work, Our Way
When you choose Gary Duff Designs, you’re trusting a family that understands this land and stands behind every project we build. We design with honesty, build with intention, and treat every property as if it were our own.
Guidance from Gary Duff Designs
Decades of experience have taught us a few things, here’s what most clients want to know before we start.
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Because your home deserves personal attention, not just project management. At Gary Duff Designs, our family stays involved from your first consultation to the final walkthrough, ensuring every design decision reflects our standards and your vision.
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Legacy and intention. We’ve spent 50 years shaping Long Island’s landscapes with design that honors architecture, enhances lifestyle, and endures for generations. Every project is guided by experience, artistry, and our family name, values that never change.
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Not at all. While many of our projects are full outdoor living transformations, we also take on select smaller projects, starting around $10K, when the fit and design goals are right. What matters most to us is your commitment to quality and collaboration.
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Always. Whether it’s Gary, Adam, or Eric, one of us remains personally involved through every phase, from design to build, so you always have a direct line to the people responsible for your project’s success.
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We only use materials, techniques, and trades we trust. After decades designing and building across Long Island’s unique terrain and climate, we know what lasts, and we never compromise on the details that define a Duff design.
Celebrating 50 Years of design excellence
50 Years of Designing Outdoor Spaces
10,000+ Projects That Transform How People Live.
Enhancing The Quality Of Life Through Landscape Design
For five decades, the Duff family has been redefining outdoor living across Long Island, one purposeful, beautifully built space at a time.