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

Natural Stone Patios 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
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.
Natural Stone Patios, start to finish.
Built from the ground down.

A natural-stone patio is the part of a landscape you live on. It carries the table, the chairs, bare feet in summer and snow load in winter, and it has to hold its line through every freeze and thaw for decades. That is why we build from the ground down before we build up. Most patios fail at the base, not the surface, so we excavate to the right depth for the soil we find, lay and compact a graded aggregate base in lifts, and grade for drainage that moves water away from the house. The stone you see is the last decision, not the first.

Within hardscaping we lay flagstone and full-depth natural-stone patios, interlock in the formats and finishes that suit the architecture, walkways that connect the property without feeling like a path bolted on, and steps cut and set to a comfortable, consistent rise. We build retaining walls that are engineered to hold grade rather than just dress it, set stone coping that finishes a wall or pool edge cleanly, and lay driveways meant to carry real weight. James is a third-generation stonemason, and the difference shows in the joints, the cuts around a curve, and the way a level run of coping reads from across the yard.

Material choice is where a patio is won or lost, and it is rarely about price. Natural stone — flagstone, granite, limestone, full-stone treads — ages and weathers in a way no two installs repeat, and we help you weigh it against quality interlock, where we are a Unilock Authorized Contractor working with warranty-grade product. We talk through colour, format, finish and how each option lives with your home, your grade and your climate before anything is ordered. The goal is a surface that looks intentional in year one and still looks right in year twenty.
The work runs on our own equipment and our own crews, which is why the site stays tidy and the schedule holds. There are no subcontractor gaps waiting on someone else's machine, and no bin parked on your driveway for weeks — all excavation spoil and demolition debris leaves in our trucks, every day. James communicates daily from the first site visit to the final sweep, the crews are WSIB-covered, and the company carries $5 million in liability insurance. You get the build quality of a large outfit with the accountability of the person whose name is on the work.
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 bins.
Project Completion
After a final walkthrough, the only thing left behind is your finished space — built to gather on for generations.
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."
Natural Stone Patios in Mississauga, answered.
Not when the base is built correctly, which is most of the work you never see. We excavate to the proper depth for your soil, compact a graded aggregate base in lifts, and grade for drainage so water moves away rather than pooling and freezing under the stone. A patio fails from the base up, so that is where five decades of experience earns its keep.
Both can be the right answer depending on the home, the grade, the budget and the look you are after. Natural stone — flagstone, granite, limestone — weathers with character no two installs share; quality interlock offers consistency and a wide range of formats, and as a Unilock Authorized Contractor we build it with warranty-grade product. We walk you through colour, format and finish against your specific space before anything is ordered.
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
Natural Stone Patios nearby
Natural Stone Patios 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