Sun, Heat + Light: A brief intro to this fundamental source of Life on Earth

In the Mid-Atlantic bioregion where we live and practice EarthCare, July is one of the months with the harshest conditions. It gets hot, and can get very dry (drought) at times, which can put stress on plants, especially ones that are already struggling to survive in less-than-ideal habitats.


Harsh conditions give us a great opportunity to observe our environment, and plan for how to protect plants, soil, water and wildlife, as they continue to face adverse conditions into the future.


When the days are long and hot, what better resource to observe in your space than sunlight? Keep reading to learn about the fundamentals of light and heat, how they impact the land, and how to observe it in the places where you practice EarthCare.


Photo: Eric Tastad via Flikr



The Importance of Sun


In permaculture design, sunlight is an abiotic “sector” that must be observed and considered when planning your gardens. Curious about permaculture techniques and terminology? Read more here.


Plants need sunlight (some more than others) to create energy through photosynthesis that gets passed up the food chain to humans…we’re going to assume you know this story! To review the basics of how sunlight supports all life on Earth, watch this video.


The fundamental fact to highlight here is this: sunlight grows life - on land AND underwater. As land stewards, we always remember that what we do on the land has downstream effects throughout the ecosystem, and especially our waterways.


Summer light and heat, plus runoff water (increased by dry, compacted soil conditions) full of fertilizer from farms, lawns and landscapes, combine to create algae blooms. Algae thrives on excess nitrogen in the fertilizer, plus ample summer sun, and multiplies on the surface, blocking essential light from plants and aquatic life that depend on just the right amount of sun filtering down through the water. These algae blooms create dead zones in waterways that jeopardize the delicate balance of life in this dynamic ecosystem.




→ Read More: Fertilizer Runoff Overwhelms Streams and Rivers--Creating Vast "Dead Zones"


So, as tempting as it is to spread fertilizer on your wilting plants in the summer, to bring them back to life, or to encourage bigger growth, our recommendation is - don’t do it!


The best ways to grow happy plants are to build healthy soil and give them the right conditions.


There are things you can do to build soil throughout the year, for plants that need richer soils. Check out our blog all about soil to learn some tips + techniques here.


There are also loads of sun-loving native plant species that thrive in harsh, hot, dry, compacted clay, which is similar to the majority of our lawn-scapes. These species can be found thriving in wild meadows, which often emerge from abandoned lots in previously human-dominated areas, or crop up after natural events.


Understanding Sun-Related Conditions for Planting


Our job as ecological gardeners is to understand the land we want to steward, through observing and interacting, so we can make good decisions about which native plants to invite into the space, and where they will thrive best. While it’s true that plants are resilient and can be transplanted at the right times of year (not summer) without harm, it’s always smart to give them the best possible chance.


One way to gain a better understanding of which native plants like more sun vs. more shade is to get out into Nature and observe the plants you see growing in different habitats.


When you take a walk in the woods, you’ll notice a lot of healthy, happy plants that love the shade of the forest canopy. These would not be good species to transplant or purchase for your front yard garden beds. You’ll find beautiful inspiration for your full sun beds if you explore a native meadow, however! Plants that thrive in sunny, hot dry conditions in the wild are the most resilient plants you can choose for those dry, hot, sunny areas in your landscape.


→ Bowman’s Hill Wildflower Preserve: Native Plants for Meadows – Dry Site


So, slow down and take time to make observations of the sunlight conditions (and others!) on your site and what’s happily growing in the wild, before making final decisions about which plants will live where.


→ Use the Seek app to ID!


In the wise words of Lao Tzu, “Nature does not hurry, yet everything is accomplished.”


→ Read More: Understand Your Garden's Sun and You'll Know What to Plant Where





How to Observe Patterns of Sunlight



Here are a few tools, tips + resources for mapping and understanding sunlight conditions in your landscape.


Prairie Nursery: Choosing Native Plants for Your Location

Dyck Arboretum: Defining Sun Requirements for Native Plants

Milkwood Permaculture: Design Basics - Mapping the Sun on Your Site

Sun Mapping App!



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