An article just popped up on my news feed regarding the ongoing litigation in the United States about the herbicide glyphosate. This is something I use and recommend for aggressive perennial weeds in the garden. Unfortunately, there is some hysteria over the use of this product, which to date has not been backed by objective data. I direct you to the article I'm referring to as published in the Financial Post.
Frequently I have clients that have decided there is something wrong with their soil and we should dig it up and replace it or at least remove several inches of soil and add something to it to make it better. In Calgary, our soil is clay rich, which helps it retain moisture as well as nutrients. I usually recommend adding one inch of compost to flower beds if the soil is particularly heavy as compost can improve soil structure, drainage, and add nutrients.
Unfortunately there is now a lot of information/misinformation available to consumers about gardening practices. Some of these ideas are not based on science and frustrate me to no end. One of my favorite sources for information is The Garden Professors. Their mandate is to provide research-based information on creating and sustaining gardens and landscapes to the general public. I will direct you to their blog on amending soil for more information on this topic.
Amending Soils - Why??
I know many of you desire a low-maintenance weed free garden and who doesn't? You may be tempted to add landscape fabric in an effort to eliminate or reduce weeds. Don't do it!
Over time, organic matter will find it's way on top of the landscape fabric. This will then provide a media for weed growth on top of and through the fabric. As most landscape fabrics are covered with inorganic or organic mulches, weeds will also grow into these mulches. As many weeds are perennial in nature, the entire root must be removed to eliminate regrowth of the weed. This becomes difficult when the roots are growing into the fabric and mulch. If you thought weeding was tedious before, you will be pulling your hair out once you have a tangled mess of weeds, landscape fabric, and mulch.
In addition, your garden plant roots may also become tangled into the fabric. Any attempt to remove the fabric can damage the roots. If you like to split your perennials and occasionally move plants around, this task becomes much more difficult.
Landscape fabric will degrade with time, especially when exposed to sunlight. It is not a permanent solution. The best solution for your garden is an organic mulch with no landscape fabric. See my blog article on Benefits of Mulches.
As a scientist, rigorous research and peer review are necessary to ensure pseudo-science and anecdotal "evidence" do not influence decision making. I recently found this video on YouTube from an Alberta gardener in Edmonton - Alberta Urban Garden. This video outlines 5 popular garden myths and why they aren't true.