East York Back Lawn

(Question)

Can I eliminate the lawn by just using black landscape fabric over it and bags of mulch?
What low lying evergreens, that take minimal care, would you suggest as I am away alot.
Soil is essentially clay.

(Answer)

Thank you for contacting the Toronto Master Gardeners.  The method of lawn removal you describe is called solarization or occultation. The difference between the two is the type of tarping used (clear for solarization and opaque or dark for occultation).  Clear tarps will heat up the ground faster as dark material absorbs some of the sun’s rays.  Most experts suggest plastic tarps but landscape fabric will work – it will just take longer.  To remove lawn on a site with clay soil, you will benefit from a method that includes the addition of compost, which will begin to help amend and improve your soil structure.  This link from the City of Guelph provides instructions Replacing grass with a garden but briefly, cut your lawn as short as you can. Water it well as moisture is key to speed the decomposition of organic matter. Adding a layer of newspaper (several sheet thickness) can further help to block out light and decomposes well.   Then top with a few inches of compost and cover with a tarp and weigh the tarp down.  The time needed to kill the grass and weeds will be at least 4-6 weeks depending on temperature and weather conditions – the hotter the better.  The longer you wait the more advanced the decomposition.  When you remove the tarp, mulch with more compost and / or wood chips or bark mulch.  Moving forward, clay soil will be improved by the regular addition of compost.  Beneficial micro-organisms in the soil may also be killed by the solarization / occultation process so the addition of organic matter will help to revitalize this important element.    This link from the University of Minnesota also provides good information UMN solarization vs occultation.

The Toronto Master Gardener’s Gardening Guide to Lawn Alternatives and Organic Care of Ground Covers provides suggestions that may be helpful in determining what to plant next Lawn Alternatives and Ground Covers

When choosing drought-tolerant shrubs, you will need to also consider your light conditions.  The City of Guelph has a good list of drought-tolerant and native species which may be helpful Drought Tolerant- Native Plants .  Your local Nursery will also be able to advise you regarding available plants and shrubs that will work well in your space.

Whatever you choose to plant, some water will be necessary. You may consider setting up a soaker hose or drip irrigation, which will conserve water use and can be set with a timer to water while you are away.   Mulching round your plants will also help to hold moisture in the soil and is recommended.

Best of luck with your project!