I live in North Toronto near Eglinton Park, which used to be a brick yard. The soil in our backyard is clay. We have a number of trees shading the garden and we are the lowest yard so we get the drainage from all the yards around us. The back garden floods every spring and even now, Apr. 25, is just mud. The grass won’t grow but the moss is flourishing. My question is: If I were to buy a few yards of sand, spread it over the ground and dig it well in to a depth of 1 to 2 shovels deep would this lighten up the soil enough that I could put the area to a shade garden? I am a senior and would do it myself. Many thanks for considering my questions.
Thank you for contacting Toronto Master Gardeners about your waterlogged yard.
We recommend that you do not dig sand into your clay soil. This combination creates a cement-like consistency in the existing soil. It is best to use organic material to break up clay soil. Compost is excellent but you can use other organic matter such as wood mulch, composted manure, shredded leaves, cover crops and composted pine bark. Of course you should incorporate these organic materials into the clay when it is no longer muddy.
In order to drain the area of excess water, the best solution is to install a French drain which is basically a gravel-filled trench sloped slightly so that gravity carries the water to an exit point at the end of the trench. This article describes a simple type of French drain: https://www.thespruce.com/how-to-install-french-drains-for-yard-drainage-2131133. A second article provides more information https://www.easydigging.com/guide/drainage/installation-french-drain.html
Before you dig, the law requires you to contact Ontario One Call to locate and mark underground pipes and wires. Contact them at least one week in advance of starting your project. Call 1-800-400-2255 or submit your request online. This 24/7 service is offered free of charge.
Raised beds within a wooden frame might be a preferred solution for a garden in the waterlogged area, or perhaps create a bog garden there.
We wish you well in solving your sticky problem.