Topdressing (Spreading Compost) on Your Yard

Spreading a thin layer of compost over your lawn and flower, tree and shrub beds is one of the best ways to restore soil micro-organisms that may have been harmed by pesticides, add nutrition to your plants, and keep your yard healthy.

Spread about a 1 cm. or 1/4 inch layer of compost on your lawn. You can rake it in a bit in the grass - often a leaf rake works well for this. On your beds - you can add up to an inch or 2.5 cm. of compost. If your beds are mulched, it is best to pull back the mulch and put the compost under it.

To figure out how much compost you will need, use this formula:
length (in feet) x width (in feet)  x depth (in inches) divided by 324 = cubic yards needed.
For example, if you are going to spread 1/4 inch of compost on your back lawn and the lawn is 12 feet by 20 feet, then you need:  12 x 20 x .25 divided by 324 = .2 cubic yards.
(Most people calculate this in feet, inches, and yards - if you do cubic metres it’s almost the same amount as cubic yards)

Most urban yards need about a cubic yard of compost for the lawn and beds. The cheapest and often easiest way to get the compost is in bulk. A pick-up truck box usually takes about 1  1/2 cubic yards of compost. See below for bulk compost suppliers.

Check our landscaping companies list for companies that will spread compost on your yard for you. Look for Tinkerbell Gardens and Top Spray,

Where to get Bulk Compost

Locally made compost will be best for your soil and plants because it will have micro-organisms adapted to the local climate and ecosystem. The most economical way to buy compost is in bulk. You can take containers or your pick-up truck to a local supplier to be loaded. Most suppliers will also deliver a load to your yard. For delivery, you may need to call a while in advance with some suppliers.

Most landscape supply companies and some garden centres also sell compost in bulk. You will probably pay less by getting compost directly from a supplier.

Local Compost Suppliers:

Bow Point Nursery -, Springbank, 686-4434.

Top Spray - - 305 Griffin Road West, Cochrane

Western Canada Compost -, 251-9639.

Money’s Mushrooms-off Highway 2 north of Airdrie - gives away it’s mushroom substrate - a mix of manure, straw and other things - every Mother’s Day weekend. Take your pick-up truck (they have loaders to fill you up) or containers and load up. Note that this compost has not yet finished composting. It’s best to let it sit in a pile or bin for a season before using it on your yard.

How to Make Your Own Compost

The City of Calgary has a wealth of information on how to make your own compost. Click here.

Be patient. If you work at it, you can get good compost in two months in Calgary. Usually though, it takes a season or two.

Garden centres and hardware stores also now have tumbler type composting bins that can make compost a little faster. They will cost $200 - 250. You can try Lee Valley Tools or Rona. Gardening magazines usually have more expensive tumblers advertised in the classified sections at the back of the magazine.

Worm Compost

Compost made by worms is considered to be among the best composts. Usually people buy it in smaller quantities for their special plants and houseplants. You can make your own too!

Here are some local resources on worm composting (also called vermicomposting): - a private company that can set you up with a worm composter

Clean Calgary’s information on worm composting.

If you want to buy worm compost in bulk, contact Gillian McDonald in Cremona (about 45 minutes drive north of Calgary)  at 461-2782 or She has a large scale worm composting operation called Worm Croft.

Click here for actions you can take to support a pesticide bylaw