The Scent of Spring

March on the south coast of British Columbia where I live, came in like a lion. Strong, cold winds gave us pause after enjoying spring-like sunny conditions just the week before. The gusty winds brought back memories of the lovely poem by Christina Rossetti:

Who has seen the wind?
Neither I nor you.
But when the leaves hang trembling,
The wind is passing through.
Who has seen the wind?
Neither you nor I.
But when the trees bow down their heads,
The wind is passing by.

Noticeably, in this blustery early spring weather, is that familiar earthy scent that comes from soil when it is disturbed for the first time in months. The soil is home to many types of bacteria, one of which is Streptomyces. This bacteria produces a molecule called geosmin. When the soil in spring is disturbed by rain, wind or other activity for the first time in months, it releases the geosmin. This is what fills our nostrils with the wonderful smell that we strongly associate with spring time. The geosmin molecule and hence the bacteria Streptomyces that produce it, attract a six legged insect called Springtails. The Springtails facilitate spreading of the Streptomyces bacterial spores. This symbiotic relationship is just one of many that exist in our complex soil biomes(1).

The smell of spring may inspire us to rush out into the garden and get our hands into the soil. The equinox on March 20th marks the first day of spring and a time for new beginnings.  As we work to build healthier and more resilient gardens, our March gardening activities should always consider the inhabitants of the ecosystems around us. Insects play a vital role in those ecosystems. In addition to their important role in healthy soil and pollinating plants, they are food for the birds. A healthy, biodiverse garden is brimming with life and includes both beneficial, and non-beneficial insects with predacious varieties to keep them in check.

As tempting as it is to engage in spring clean up by removing the standing dead plants and leaves on the ground, waiting has its benefits.  Many pollinators will be hibernating in dead plant material. Give them time to wake up and emerge when they’re ready. Also remember that wherever feasible, leave the leaves as a nutritional mulch for the soil. Consider allowing your dandelions to flower in early spring if you don't have early blooming native plants in your yard. They can be an important source of pollen and nectar for bumblebees. 

Spring is a great time to integrate native plants into your garden. Native plants are an essential support for native insects and birds. They are the dedicated source of food, pollen and nectar for the insects and animals in our garden ecosystems because they have evolved together over time. The National Wildlife Federation suggests we should  strive to incorporate 50%-70% native plants (2) in our gardens to increase biodiversity. It can be satisfying to know your garden is a small and achievable way to support and even restore biodiversity. 

Keystone species (3) of native plants for your region build a strong foundation for ecosystem health as they provide the main pillars of support. Local, and organically grown when possible, native plants and seeds should be selected. Native plants are naturally well-suited to their native ecosystem. They have adapted to the conditions that most non-native plants might suffer and will have an advantage during the unforeseen stressors associated with climate change. 

The symbiotic relationship that exists between native plants and native bee populations cannot be overemphasized.  Up to 60% of native bee species are specialists when it comes to pollen, relying on native plants to feed their young.  A drastic reduction in native plants has led to native bee populations plummeting. This is concerning, as native bees are much more effective pollinators than non-native honey bees (4), allowing for more successful pollination and seed-production of native plants.

This spring nourish your garden soil and the organisms that inhabit it, to encourage biodiversity and sustainability in your garden ecosystem. Spread a thin layer of compost or vermicast on your garden beds and top dress your lawn with it as soon as the ground is warm and dry. Compost tea can be applied directly to the soil and plants. It is a good option if you don’t have a large compost pile to draw from. Effective Microorganisms (EM) as a commercially available solution can be applied directly to your soil, lawn, and compost. You can also use it as a foliar spray or to assist in seed germination. 

Written by Ann Moolin

To source EM and many more products that are both good for your garden and the planet check out The Organic Gardener’s Pantry.  

To further your learning about ecological gardening tips or native plants check out the following courses: Organic Master Gardener   Ecological Plant Knowledge 1 - Natives

Some data bases to explore when selecting pollinator and native plants for your garden this spring

https://naturaledge.watersheds.ca/plant-database/ 

https://pollinatorpartnership.ca/en/ecoregional-planting-guides 

References:

1. Bush, Matthew; Buttner, Mark J.  (April 6, 2020) Research Unearths The Science Behind The Smell Of Spring. https://www.jic.ac.uk/Press-Release/Research-Unearths-The-Science-Behind-The-Smell-Of-Spring/

2. Phillips, Mary. (July 26,2024) National Wildlife Federation Blog https://blog.nwf.org/2023/04/plant-50-to-70-native-benefit-more-wildlife/

3. National Wildlife Federation. https://www.nwf.org/Native-Plant-Habitats/Plant-Native

4. Page, Maureen L.; Williams, Neal M. (December 1, 2022) Honey bee introductions displace native bees and decrease pollination of a native wildflower. https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.3939