I want to plant evergreen trees, grass or vine close to the fence beside a water path. Photo attached. The purpose is for privacy and to serve as wind breaker in winter. Full sun exposure in the morning, and exposure will decrease in the afternoon. The soil is wet most of the time due to water in the neighbourhood flow through my house towards a catching basin in my next door neighbour. I’m located in North York. It’s a new subdivision, and I’m assuming the soil is clay. The backyard is not big, so I do not want to plan big trees. I prefer low maintenance trees, grass or vine. It would be much appreciated if you could provide some options. Thanks a lot!
Thank you for contacting the Toronto Master Gardeners with your inquiry.
The reason that plants do not thrive in boggy, soggy soil is because plant roots require oxygen in order to function. When the soil becomes completely saturated with water there is no room for air. There are some trees and shrubs that may tolerate these conditions but in most cases they will often grow poorly and will be more susceptible to soil borne diseases.
In your specific case you have a two fold problem: not only do you have poor drainage but you also have soil with a high clay content. Clay soil contains tiny mineral particles and tiny air spaces, which absorbs water more slowly. Picture a jar of marbles (sand) vs a jar of flour (clay) – water runs through the first instantly, while it might simply sit on top of the latter.
PennState has an excellent article on Trees, Shrubs, and Groundcovers Tolerant of Wet Sites. It lists a number of trees and shrubs which would be suitable for your needs along with their hardiness zones.
The key to success when planning any garden is to plant the right plant in the right place. Instead of fighting with the planting site or quality of soil why not look at it as an opportunity to grow plants that are able to thrive in a boggy environment.
Garden Making magazine has an excellent article 16 plants for boggy soil listing plants for soggy shade as well as soggy sun locations.
The RHS-Royal Horticultural Society has an excellent article on Bog Gardens
The Toronto Master Gardener post, Flowering perennials for wet boggy areas also gives a list of perennials suitable for this type of environment.if you do not want to excavate the soil to create a bog garden you may wish to think about creating a container bog garden. This link gives step by step instructions.
Good Luck.