"Working with James was great from the beginning. He put my mind at ease with his product knowledge and his creative designs."
Outdoor Luxury · Mississauga, GTA
Outdoor Living Spaces in Mississauga.
Astonia Landscaping brings owner-led landscape design and natural-stone masonry to Mississauga. James Dennison, a third-generation stonemason, has built grounds for discerning homeowners across the Greater Toronto Area since 1975 — and the western edge of the GTA, with its established estate streets and its newer luxury builds, is squarely the kind of work we take on.
- Since 1975
- 3 Generations
- $5M Insured
- WSIB Covered
- Unilock Authorized
In Mississauga
Landscaping that belongs in Mississauga.
Mississauga is two cities at once, and the difference shapes the work. South of the QEW, enclaves like Lorne Park, Mineola and the stretch along Mississauga Road hold some of Peel's oldest estate lots — deep, generously treed parcels where mature oaks and a settled grade are part of what the property is worth. North and west, the luxury builds are newer and larger, often on cleared ground that has yet to grow into itself. We approach the two differently: one asks for restraint and protection of what is already there, the other for design that gives a young property weight and a sense of permanence from the start.
Homeowners in these neighbourhoods tend to be making a once-in-a-generation investment, and they care about how the work is carried out as much as the result. Owning our own small and heavy equipment means we move on our own schedule rather than waiting on subcontractors, which matters on the narrow, established frontages off Mississauga Road where a job can sit exposed to the street. We haul every load of debris away in our own trucks — no bins parked on the boulevard for weeks — and our crews are WSIB-covered and backed by $5M in liability insurance, which is the baseline these homeowners expect.
The mature estate lots reward careful reading of the site. Old trees with protected root zones, long-settled grades, and the drainage that comes with a deep, sloping property all have to be respected before the first stone is set, and natural stone laid for these grounds should look as though it has always belonged. As a Unilock Authorized Contractor, we also work in engineered hardscape where a newer build calls for it. Either way, the priority is the same — a landscape that suits the house and the street and holds up for decades.
What we build
Outdoor Living Spaces, start to finish.
Outdoor Kitchens
Fireplaces & Fire Pits
Pergolas & Pavilions
Landscape Lighting
Outdoor Living Rooms
Stone Fire Features
The craft
Built from the ground down.
An outdoor living space is the part of a property a family actually uses — so we build it to the same standard as the rooms inside the house. The work spans outdoor kitchens, fireplaces and fire pits, pergolas and pavilions, full landscape lighting, and the seating, dining and lounging areas that tie them into one place you can spend an evening. Everything is designed as a single composition, anchored in natural stone, and laid out so the cooking, the fire and the gathering all face the same direction — toward the people you built it for.
The masonry is where this work earns its place. James is a third-generation stonemason, and the kitchens and fireplaces are built the way a chimney is — proper footings below the frost line, a structural core, and a hand-laid natural-stone face rather than a veneer pinned to a box. Outdoor kitchens are framed for the equipment they'll carry, with stone counters, weather-rated cabinetry and the gas, water and drainage run in before the first stone is set. Fireplaces and fire pits are built to draw and vent correctly, sized to the space so the heat reaches the seating instead of climbing straight up. Pergolas and pavilions are set on real foundations to hold their line through Ontario winters, season after season.
Lighting is treated as part of the build, not an afterthought wired in at the end. We layer it — low light washing the stone, soft fill at the steps and paths, a warmer pool over the dining and fire areas — so the space stays usable and beautiful well after dark, through three seasons of the year. The result is one continuous outdoor room: a place to cook, eat by the fire and stay outside longer than you planned, designed and built by one crew so the kitchen, the hardscape, the lighting and the planting around them all read as a single, deliberate whole.
Because Astonia owns its own equipment and hauls every bit of debris away in its own trucks, a build of this scale moves on its schedule, not a subcontractor's — and your property stays clear, with no rented bin parked on the drive for weeks. James runs the project himself and stays in daily contact from the first layout to the final light being aimed. Crews are WSIB-covered and the company carries $5M in liability insurance, and as a Unilock Authorized Contractor we build to a standard that's independently backed. It's a serious, once-in-a-generation investment, and we treat it that way from the day the stone arrives to the night you first light the fire.
How it works
From first handshake to final reveal.
01
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.
02
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.
03
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 bins.
04
Project Completion
After a final walkthrough, the only thing left behind is your finished space — built to gather on for generations.
The Astonia difference
Why homeowners in Mississauga choose us.
Owner-led
Daily communication from James, from the first handshake to the final reveal.
Our own equipment
Small and heavy machines, run by our own crews — no subcontractor delays.
No unsightly bins
We haul every bit of debris away in our own trucks, every day.
$5M insured
Liability coverage above the industry average, for your peace of mind.
WSIB covered
A fully covered, professional crew on every project.
Unilock Authorized
Warranty-grade materials and professional installation standards.
Kind Words
Homeowners across the GTA, on the Astonia experience.
Five decades of referrals across the GTA & Durham — and a Unilock Authorized Contractor. 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."
Good to know
Outdoor Living Spaces in Mississauga, answered.
Yes. The masonry is built for Ontario winters on footings set below the frost line, and the fireplaces and fire pits are sized and vented to throw heat toward the seating — so the space stays comfortable well into the shoulder seasons. With the lighting layered in, most clients use these areas three seasons of the year rather than just the warm weeks of summer.
We plan and coordinate all of it as part of the build — the gas line for the cooking and fire features, water and drainage for the kitchen, and the wiring for layered landscape lighting — and it's run in before the stonework goes up. Because one crew designs and builds the whole space, the services are roughed in at the right stage instead of being retrofitted later, and licensed trades are brought in where the work calls for them.
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 — our crews are fully WSIB covered, and we are a Unilock Authorized Contractor.
More services in Mississauga
Outdoor Living Spaces nearby
Outdoor Living Spaces in Mississauga, done right.
Book a free on-site consultation. We design, build and plant the whole space — then haul it all away when the last stone is set.
$5M insured · WSIB-covered crews · 3rd-generation craftsmanship since 1975