Building a Lasagna Garden Bed

One of our new garden projects this summer was building a lasagna bed around the base of this Big-leaf Maple. It's roots are exposed in some places and the mower keeps cutting them. They need protection.

Also, this will be the comfrey plant supply bed. We will cultivate comfrey plants here then transplant them to other beds to do the job of building up the soil and providing nutrients for other plants in the bed.

A house down the street put lots of flattened cardboard out for the taking.

It is the perfect 1st layer. It kills off the grass below then breaks down, adding organic matter to the soil.

While building up the next layers we kept the hose running on the cardboard to thoroughly wet it.

In the compost area there are piles of paper, coffee grounds, grass clippings, horse manure and leaves.

All of these were added in thin layers with a sprinkle of glacial rock dust every so often. The rock dust provides minerals to soil organisms so they can do their job.

All of our household paper is recycled except for the shiny stuff  that has undesirable chemicals in the inks.We put that out in bags for the city's recycling program. 

We kept the hose running on the pile as we built up the layers to provide plenty of moisture for the chemical reactions that need to take place.

The pile was covered with cardboard and left to 'cook'. 

A compost thermometer monitors the temperature and a water reader monitors the moisture levels. The pile needs to pass through a number of different temperature zones for a wide variety of soil organisms to become active in breaking down the materials. If the pile gets too dry over these hot summer days we need to water it.

 We have run out mulch so used cardboard to cover the new bed until we get more. As unsightly as it looks, we have found the cardboard is doing a good job at conserving moisture.

We were careful to not build up the bed against the tree trunk. Any soil or other material piled up against a tree trunk will rot its bark and could cause its premature death.

Look out for this project's update.