Replaced the Dog Pee contaminated lawn with a flower bed

(Question)

One of our dogs had peed the lawn, and for the past 4 years there has been as bald patch in front of our flower bed. Instead of replanting the lawn, I would like to extend my 3ft flowerbed to a 6ft lower bed. Would I have to treat the soil first? Are particular perennials/annuals that will not grow there?

(Answer)

Thank you for contacting the Toronto Master Gardeners with your intriguing question. We love the idea of you converting your lawn, which is a monocrop, into a diverse flower bed, which has the potential of attracting even more pollinators.

However, as my friend who is a great dog lover has told me, if your dog likes peeing in this area, they are not going to stop doing so. I believe you could create a run for them to pee in and train them to go there. Or have an area of lawn where you replace the lawn with white clover. Dogs like peeing in the highest spot and the clover will grow higher than the lawn, and will attract your dog. The dog pee will not kill the clover.

Lawn burn is caused by a high concentration of nitrogen and salts in the dog’s urine. Nitrogen is good for grass but when dog urine is deposited in one small spot the amount is excessive, causing injury or death to the turf. A way to prevent the grass from dying is to pour at least three litres of water on the spot as soon as possible.

Converting any piece of lawn into a flower bed will differ depending upon such criteria as water drainage, sun exposure, and soil type. But general directions would include:

  • Dig up the top layer of lawn. You can turn this over so that the nutrients of the grass are not lost. Or you can remove and compost these pieces of lawn first and then place them on top of the bed.
  • To give the garden bed a good beginning, add soil. A good composted loam is the most versatile of soils. The guideline for adding a layer of new soil is that it should not exceed four to six inches.
  • Give the soil and bed some time (at least a few weeks) to settle and then plant. Each year, the soil will improve as will the garden bed.
  • You asked for plant suggestions. That will depend on the sun exposure, moisture content of the soil, the level of organic matter in your soil, and your garden growing zone.
  • The Toronto Master Gardeners are strongly recommending that gardeners do plant Ontario native plants and do not plant invasives. The How (and Why) to Use Native Plants found on the Halton Master Gardener Website is an excellent article and provides lots of additional information of native plants. Grow Me Instead lists native non-invasive plants for your garden.
  • The Toronto Master Gardeners has a Gardening Guide on Pollinator Garden which lists some key elements to creating a pollinator garden along with a list of native and some non-native plants. Selecting Plants for Pollinators along with Pollinator Plants for Great Lakes Region are two excellent resources that list plants along with the pollinator that they attract.

Best of luck with building your new garden bed.

January 31, 2022