"Working with James was great from the beginning. He put my mind at ease with his product knowledge and his creative designs."

Landscape design & stone masonry in Oakville.
Astonia Landscaping designs and builds high-end residential landscapes and natural-stone masonry for homeowners in Oakville. Owner-led by a third-generation stonemason, the firm has worked across the GTA and Durham Region since 1975. Every project is owner-led, with daily communication from the first consultation through the last stone set in place.
- Since 1975
- 3 Generations
- $5M Insured
- WSIB Covered
- Design-Build
Landscaping that belongs in Oakville.
Oakville rewards patience. Many of its finest properties sit on generous, mature lots in Old Oakville and along the lakeshore, where established gardens, decades-old trees, and stone walls already give the land its character. Building well here means working with what is already there rather than clearing it away. We design around the trees worth keeping, match new masonry to the weight and tone the street already carries, and treat the existing garden as a starting point, not an obstacle. The result should look like it has always belonged.
Homeowners in this part of Halton tend to be design-led, and they have usually lived with their property long enough to know exactly what is missing. They notice how a stone wall is coursed, how a step meets a path, how a terrace sits against the house. That kind of attention is the reason we work the way we do. As a third-generation stone family, we handle the natural-stone work and the design intent personally, and because Astonia owns its own equipment and runs its own crews, the property stays calm and orderly through a build that may run many months.
The lakeside setting brings real site considerations. Lots closer to the shore deal with grade changes, drainage, and mature root systems that all have to be read carefully before anything is built, and established neighbourhoods often mean tight access and close neighbours who would rather the work be carried out cleanly and quietly. Astonia is fully WSIB-covered and carries $5M in liability insurance, and we hold our hardscape work to a standard meant to last in this climate. The aim on every Oakville property is craft that settles into the place and looks better with age.
From first handshake to final reveal.
Initial Consultation
We meet you on-site to walk the space, understand how you want to live in it, and talk through your vision and investment — no obligation.
Design & 3D Review
Our designer measures and plans your space, then renders it in 3D so you can see it before we break ground. We refine every detail together.
Breaking Ground
Our own crews and equipment start at 7:00 AM, keep the site clean every day, and brief you each morning and evening — no subcontractor gaps, no delays.
Project Completion
After a final walkthrough, the only thing left behind is your finished space — built to gather on for generations.
Why homeowners in Oakville choose us.
Owner-led
Daily communication from the owner, from the first handshake to the final reveal.
Our own equipment
Small and heavy machines, run by our own crews — no subcontractor delays.
Built to last
Overbuilt foundations and natural stone, meant to hold their line for generations.
$5M insured
Liability coverage above the industry average, for your peace of mind.
WSIB covered
A fully covered, professional crew on every project.
Design-build in-house
One team designs, builds and plants — no trades to chase.
Kind Words
Homeowners across the GTA, on the Astonia experience.
Five decades of referrals across the GTA & Durham. Read more on Google& Houzz.
"The natural stone work and landscape job that James and his crew did is beautiful, outstanding work. The quality is outstanding — we would recommend this company to anyone."
"Astonia was a delight from start to finish. The crew showed up early and worked long days to finish on time. We are now enjoying the most amazing front yard. Outstanding results!"
"As a repeat client, we selected Astonia to transform our simple backyard into a relaxing space amongst a natural setting that will bring us many years of pleasure."
Landscaping in Oakville, answered.
We design and build across the GTA & Durham region — including Toronto, Etobicoke, Mississauga, Brampton, Oakville, Vaughan, Markham, Newmarket, Aurora, King City, Whitby, Oshawa, Bowmanville and the surrounding areas.
Every project is different — from focused stonework to a full landscape transformation — so we provide a clear, detailed proposal after an on-site consultation rather than a generic price. Most of our work is a meaningful, lasting investment in your property.
Timelines depend on scope, and you receive a realistic one at the design-review stage before we break ground. Because we own our equipment and run our own crews, we work efficiently — starting at 7:00 AM and keeping the site clean every day.
Yes. We carry $5 million in liability insurance — above the industry average — and our crews are fully WSIB covered.
Yes. Our designer visits your home to measure and plan the space, then renders your project in 3D so you can see it before any work begins. We review and refine it together until it is right.
Often, yes. We build alongside landscape designers, architects and major pool builders across the GTA, and we can also design and build the whole project in-house. Either way you deal with one accountable crew from the first site walk to the final planting.
Astonia is led by James Dennison, a third-generation stonemason with five decades of craft. You get the expertise of a large company with the warmth and accountability of a family business, owner-led from start to finish.
Your Oakville project starts here.
Book a free on-site consultation. We design, build and plant the whole space — one accountable crew from the first site walk to the last stone set.
$5M insured · WSIB-covered crews · 3rd-generation craftsmanship since 1975




