Soil Lab Garden

Hours and Location

Soil Lab Garden

Canada Agriculture and Food Museum
DateAvailable year-round
Time9:00 am - 5:00 pm
A green space with colorful planters in the background and a reader rail with photos of insects in the front.
9:00 am - 5:00 pm
Included with admission

Welcome to the Soil Lab Garden

Explore the garden, pick up a few gardening tips, and learn how healthy, living soil is key to producing ample crops.

Living Underground

Did you know that soil is home to billions of tiny living things known as microbes? Just like above-ground garden critters, some are friends and some are foes.

Soil microbes and plants inhabit the same world. They constantly interact with each other: they exchange food, protect each other from enemies and, together, they alter the soil environment to better meet their needs.

Meet Some Microbes

Plants use chemical messages to communicate with microbes. They release substances into the soil—root exudates—that attract their friends and repel their foes. 


1. Root-zone bacteria 

What are they?
Single-cell microbes that live around the plant roots.

The Deal:
These bacteria transform nutrients—minerals—in the soil into a form that plants can use. In exchange, the plants feed them root exudates.

2. Mycorrhizal fungi

What are they?
An underground network of mushroom fibres that connect into plant roots.

The Deal:
This mushroom network acts like an extension of the roots, bringing far-away nutrients and water to plants. In exchange, it feeds on sugars in the plant roots. Root exudates trigger the germination and growth of mushroom spores—fungi “seeds.”

3. Root exudates

These substances consist of amino acids (building blocks that make protein), sugars and fatty acids (building blocks of fats). 

4. Nitrogen-fixing bacteria 

What are they? 
Single-cell microbes that live in bumps on the roots of legume plants (such as peas and beans).

The Deal: 
Plants need nitrogen to grow. These bacteria turn nitrogen in the air into a form that plants can use. In return, the bacteria help themselves to sugars in the plant roots. The bacteria are attracted by root exudates.

Microbes illustration long description (Click to expand)

Illustration of a bean plant with cutaway view of the root system and soil. Four numbered circles magnify different sections of the root system. Circle 1: Close-up of roots surrounded by small, pink oval bacteria and small, blue round bacteria. Circle 2: Close-up of roots intersected with pink filaments. Circle 3: Close-up of roots surrounded by yellow circles, green squares and purple pentagons. Circle 4: Close-up of roots covered with small, beige spheres.

Microbial Starter for Soil  

Pile of peas on a white background, covered with a pink powder.

Did you know that you can boost the population of friendly microbes in the soil by adding inoculants? These live mixtures contain microbes like mycorrhizal fungi or nitrogen-fixing bacteria, which colonize the plant roots as they grow.

Home Sweet Home

Many different critters visit and live in our garden. Some are helpful, while others cause harm.
Can you tell the friends from the foes?

Close-up view of a red-and-black ladybug on a blade of grass.


✅ Friends

Ladybugs eat small pests, such as aphids, that live on and damage plants.

Close-up view of a brown spider in the center of its web.

Orb weaver spiders

✅ Friends

These large spiders eat flying insects that get trapped in their sticky, circular webs.

Close-up view of a white butterfly with a black dot on its wings, resting on a cluster of purple flowers.

Cabbage White butterflies

❌ Foes

These butterflies lay their eggs on plants from the cabbage family, such as kale and broccoli.
Their caterpillars—cabbage worms—then chew away the leaves.

Close-up view of two yellow-and-black bumblebees, foraging on a large white flower.

Bumble bees

✅ Friends

These bees pollinate flowers as they forage for nectar and pollen.

Close-up view of a small, lime green insect with long antennae and two black protrusions at the end of its abdomen.


❌ Foes

As they feed, sap-sucking aphids weaken plants and spread diseases between them.

Close-up view of a fly with red eyes and an orange-and-black striped abdomen on a pink bell flower.

Hover flies

✅ Friends

Hover fly larvae feast on aphids, while the adult flies pollinate flowers as they feed on nectar and pollen. 

Close-up view of a shiny, bronze-and-green beetle on a green leaf.

Japanese beetles

❌ Foes

These invasive beetles have few predators, and a big appetite for plant leaves, flowers and fruit. After their visit, little is left, aside from plant skeletons.

Close-up view of a wasp with a long, thread-like abdomen sipping nectar from a yellow flower.

Parasitic wasps

✅ Friends

These wasps lay their eggs inside the bodies of some insect pests. The wasp larvae then eat the pests’ insides, which kills them.

The Art of Watering

Water is essential for all living things. In plants, it carries food through stems, leaves and fruit. But plants need just the right amount of water. With too much or not enough water, plants can’t get the nourishment they need from the soil.

Just Right!

Self-watering planters water plants for us, and reduce the amount of water used over a growing season. The tank holds a large volume of water, which the soil absorbs as it’s needed. These planters give plant roots the right amount of water, in both wet and dry weather. 

1. Tank

The tank stores the water.

2. Rain filter 

After a heavy rain, surplus water drains into the tank through a mesh filter.

3. Fill port 

This is where we add water to the tank.

4. Wicking stem

This slotted plastic tube contains a fabric wick. Half of the tube dips in the tank, and the other half is in contact with the soil in the planter. The soil sucks up water from the tank, through the wick (a process called “capillary action”). This keeps the root zone moist.

5. Drainage hole

Excess water pours out from this hole.


These self-watering planters were designed and made by a company called Equinox Desert Planters, in Winnipeg, Manitoba.

Red garden planter illustration long description (click to expand)

Illustration of a red garden planter with a cutaway at the front that reveals, on the left half, a tomato plant, its roots, and a column of soil. The right side is empty and the bottom of the container is filled with water. A series of numbers are distributed throughout the illustration. Number 1 is at the bottom left in the water. Number 2 is in the center of the planter, above a gray circle with a hole in the middle. Number 3 is on top of the planter, near a small yellow ring. Number 4 is in the planter, near two long grey tubes. Number 5 is on the right, above the water and next to small hole in the side of the planter.


Be a friend to your soil    

Growing food takes a lot of time and know-how. It involves preparing beds, planting, watering, weeding and fertilizing, as well as dealing with pests, disease and bad weather. 

But by adopting some soil-friendly practices, gardeners can cut down on their workload and get better harvests, while at the same time helping underground life thrive. It’s a win-win opportunity!

Here are five things that you can do to build up healthy garden soil. 

Inside a green circle, a graphical illustration depicts a garden with mulch on the ground.   KEEP IT COVERED  

Add a layer of mulch, such as wood chips, straw or fallen leaves, on top of the soil.

This will help:

  • the soil to absorb and retain moisture
  • prevent weeds from sprouting
  • feed soil microbes and organisms
  • improve the soil

In a crossed-out red circle, a graphical illustration depicts a shovel digging in soil.   Don't Disturb it

Don’t turn over (till) the soil; plant directly into it instead. Make permanent beds and paths.

This will help:

  • maintain the soil’s structure, letting water and air into the soil
  • protect soil critters and their homes (worm tunnels, ant nests, etc.) 
  • keep established soil microbe communities working
  • reduce soil erosion

In a green circle, a graphical illustration depicts a shovel adding compost to a garden.   ADD ORGANIC MATTER

Place compost or well-rotted manure at the base of plants (under the mulch), at mid-season. 

This will help:

  • provide nutrients for plants
  • feed soil microbes and organisms
  • the soil to absorb and retain water 
  • improve the soil

A graphical illustration of a circle divided in four with a flower, a sun, a maple leaf and a snowflake in each quarter; in the center four black arrows encircle a planter box.   Plant year-round

Always have plants growing in your garden. Cut dead plants and weeds at the base instead of pulling them out, leave in legume “weeds,” such as clover, and let plants overwinter in the garden.

This will help:

  • prevent erosion
  • feed soil microbes through winter
  • enrich the soil with nitrogen thanks to the nitrogen-fixing bacteria that live on the roots of legumes such as clover.

A graphical illustration of a green circle with various white plants around the outside; in the center four black arrows encircle a planter box.   Rotate your crops

In each plot or bed, plant crops from a different plant family than the one that was growing there over the previous season.

This will help:

  • prevent the soil from becoming poor in certain nutrients
  • prevent infestations from overwintering pests
  • improve the soil
  • encourage soil microbe diversity