There is one thing that makes me shudder when a new client shows me their garden: landscape fabric. Gardens that use fabric often have predictable and avoidable problems and as a first step I usually recommend ripping it out.
Folks often use fabric as a quick fix. What happens is this: homeowners don't have time for the garden; it becomes inundated with weeds; they decide to try to smother the weeds with fabric, and usually bark mulch over top. This looks fine for a while. Then, because they still don't have time to maintain it, weeds pop up in the holes around existing plants or gaps in the fabric. Perennial weeds push their way through the fabric or send runners underneath to where they can reach light. As the mulch decays and becomes more soil-like, new weeds germinate on top and send roots down into the fabric. Now there are weeds on both sides of the fabric. Sometimes it is easy to rip out the weeds on top, but to get at anything below means pulling the fabric and all the mulch aside.
Additionally, shrubs will root into the fabric. Even though the fabric is permeable, I think it interferes with plants' water and nutrient uptake and the biological activity in the soil. The soil underneath always seems clayish, compacted, anaerobic - at least here in Cascadia. Healthy soil and plants need to be free, to breathe, feel the rain. Things seem to thrive better once it's removed.
It's also really ugly if visible where the mulch has thinned, and yet another petrochemical product we don't really need!
A few years ago we started working at a home where the previous owners used this fabric & mulch method to try to smother a pretty bad bindweed problem.The fabric ended up creating a home for the bindweed roots and the vines were popping up in every hole and gap, smothering the shrubs.. All we did was pull bindweed during our maintenance visits. We proposed to the owners a plan to remove the fabric, and they approved. So we began, and in some areas the bindweed roots were so plentiful it looked like a pile of spaghetti. We pulled these out as we went. Because the shrubs had by now rooted into the fabric, we couldn't get it or the bindweed all out without seriously disturbing the plants, so some was left in place. Now this garden only has bindweed in these area, so we spend just a few minutes pulling bindweed and can then focus on the rest of the garden.
Happy bindweed roots thriving under landscape fabric.
In another garden, the owner wouldn't let us remove all the fabric where there was a campanula & couch grass infestation. Because we couldn't access the roots, all we could do was hoe through the surface growth every week (which becomes harder as the mulch thins), meanwhile those roots spread to other parts of the garden. Very frustrating!
Fabric can be a temporary fix and works ok for annual weeds. Some farmers use it in annual vegetable production but remove it at the end of the season. It can sometimes also be used in pathways, with woodchips or pea gravel over top, but the area must be clear of perennial weeds, so it is best used as at the beginning of a landscaping overhaul, not thrown down after the fact. Yet, it's almost inevitable that weed seeds will eventually take root on top. I don't recommend it for rock gardens, because again weeds with root in and through the fabric and to access the weeds meaning shifting a bunch of rocks around which is very time consuming. Here, it may be better to use black poly, which is basically like a thick opaque garbage bag. The downside to this is that it is impermeable, so it's not great for soil and you wouldn't want it too close to shrubs.
If you have a weedy garden it is much better to invest the time and energy to getting to the literal root of the problem rather than trying for a quick fix! Hoeing or cultivating breaks the weeds' reproduction cycle, and perennial weeds need to be dug out. Keep on top of weeds by mulching and keeping as much of the soil covered as possible with plants.
More about "weeds" and tips to come!
