In Nature plants always live in communities with many other plants, forming complementary relationships with respect to light exposure, root depth, nutrient and water requirements, and so on.
This is easy to see in forests, where the large trees are exposed to full sun, but the under-storey plants live in shade.
Photosynthesis is powered by solar energy, and plant leaves are living solar collectors, finely tuned to specific light intensities. Depending on their adaptation to ultraviolet light, leaves also contain different levels of natural sunscreens.
When we design and plant our gardens it is very important to provide plants with the light conditions they require. The sensitive leaves of shade plants will burn in full sun, and sun plants are not able to get sufficient light for photosynthesis when placed in shade.
Prairie plants, such as grasses, have adapted to grow in full sun. It makes little sense to expect grasses to flourish in the shade of trees and they don’t, and so we should be thankful to the mosses when they fill in the bare spots and ensure a continued carbohydrate supply for the soil organisms.
We commonly associate companion planting with vegetable gardens, because experience has taught us that some plants “get along” well with each other, and others don’t. For instance, tomatoes grow well with carrots, lettuce and rosemary, but not with potatoes, cabbage and fennel.
The same principle applies to all plants. Those that have evolved within the same ecosystem are used to each other’s chemistry and other peculiarities and know how to live together.
Compatibility cannot be guaranteed when we group plants from many parts of the world in our ornamental gardens, even when we have taken the greatest care to provide them with the right growing conditions. It is generally easier to emulate native ecosystems, because the plants are so fully adapted to each other.
Of course our gardens can be aesthetically pleasing! We just need to be a bit more thoughtful in our plant choices and plant placement, and always remember that we are working with ecosystems.
We go much deeper into this topic in our online course, which you can discover here: