Setting Your
Soil Volume Goals

Soil Volume: The First Step in Silva Cell Projects

Soil volume is the foundation of every successful Silva Cell project. Before budget, layout, or cell count, you need a soil volume target—the number that shapes everything that follows. Why does soil volume come first?

It’s the biggest factor influencing tree health, size, and lifespan
It determines how many Silva Cells your project will need
It sets expectations for canopy growth and long-term performance

Below you’ll find important details and why soil volume is important, the reason we start here, how much soil you need, and how to set your own soil volume goals. Click below to jump to your section of interest.

Why Soil Volume Comes First How Much Soil Do You Need? How to Set Your Soil Volume Target

Why Soil Volume Comes First

When customers ask, “How much does a Silva Cell system cost?” our immediate follow-up question is: “Do you have a soil volume target?” Once we know your goals, we can begin to determine scope, number and depth of cells, and a basic layout framework.

The soil volume target is your design anchor — it guides decisions and creates clarity from the start.

In cities, the biggest limiting factor for tree health is access to enough lightly compacted soil volume. Trees
need adequate soil to grow roots and build stable, healthy structure. More soil equals:

Healthier, larger trees
Bigger, fuller canopies
Cooler streets and shaded buildings
Longer lifespans and fewer tree replacements
Higher return on investment

Silva Cells create protected, lightly compacted soil volume beneath sidewalks, plazas, courtyards, and other hardscapes.

How Much Soil Do You Need?

There is no one perfect number for every project — but research gives us a highly dependable range. A strong goal for large, healthy urban trees is around 1,000 cubic feet per tree. But we also know not every site can reach that. Space, geometry, and budgets vary. Ultimately, aim high and remember:

Bigger volumes support stronger, larger trees
There is no single number; every site is different
Shared rooting space can reduce soil volume total
Even incremental increases lead to better growth

Municipalities across North America are setting soil volume standards to ensure healthy street trees. These standards — some recommended, some required — vary, though most fall into the same 600-1,000 cubic foot range already mentioned.

CITY	SOIL VOLUME STANDARD
Toronto	30 cubic meters (1,060 cubic feet)
Minneapolis	800 cubic feet
Denver	750-1,000 cubic feet
Washington DC	600 cubic feet

CLICK HERE FOR A MORE COMPLETE LIST OF CITY SOIL VOLUME STANDARDS

How to Set Your Soil Volume Goals

Now that you’ve seen the principles and the benchmarks, here’s a helpful way to think about setting your own goals:

We aren’t after perfection right away. Just get it started. Setting a soil volume target is an inexact process. There’s no single “right” answer. What matters is identifying a goal early so we can model options and help you get the most soil volume possible within your constraints. We work with designers every day to: Settle on an achievable soil volume number, align budgets and site constraints with tree performance, maximize space and soil efficiency, navigate tight footprints and accommodate utilities.

Bring us your project’s basic plan — we’ll help hone the details. With a clear soil volume target and a flexible design process, together we can grow healthier, longer-lived trees and more resilient urban places.

The DeepRoot technical team is here to help.

Simply reach out with any questions.

Setting Your
Soil Volume Goals