I’ve recently received several questions about using landscape fabric when growing cut flowers. This is a really important question for the cut flower grower, especially if you’re interested in growing in a more ecologically sound way.
Here’s a Q&A with one of my students on this topic…
Q. I've been thinking about my summer mulching strategy and am wondering if you have some insight into my dilemma. The use of landscape fabric as a seasonal mulch is so popular with flower growers these days, and I've been using it on about half my garden beds over the past two gardening seasons, following the approach of burning holes and planting into them. I've appreciated how much it has diminished my summer weeding labor, but I am not certain it's best for my soil's health and biodiversity. When I pulled it up at the end of last season, I noticed the color and texture of the soil seemed diminished compared to leaf-mulched soil, and it was an absolute fire ant city under there! Not to mention, on a smaller scale where one bed isn't necessarily all one crop makes the rotation of crops over the course of the season really tricky with fabric. Still, living in the south where the heat and the weed pressure are so intense in the summertime, I do love the comprehensive weed suppression the fabric provides… I'm curious to hear your thoughts on these alternatives. Have you used landscape fabric in your garden, or know of anyone who's tested its effects on soil health?
A. There are many problems with landscape fabric and you’re spot-on that it is terrible for your soil health. As you know from my course, health, and in particular soil health, is the secret to a great garden that’s less susceptible to pests, disease, plant failure.
Why is landscape fabric such a problem? It’s mainly because the fabric blocks the cycling of organic matter in the soil. As a result you’re essentially killing off your soil organisms, which can cause all sorts of problems.
My approach is all about replicating and enhancing the natural processes that happen already in nature, not thwarting them (which is what landscape fabric does). Does this require more effort? Yes, but when you weight that against the risk of crop failure from disease and pests and other issues that can arise, it’s 100% worth it.
Is there any good time to use landscape fabric? I think the only acceptable use for it is in pathways, but even then, I don’t use it now that I have dialled in better methods for weed suppression (including sheet mulching with cardboard and wood chips, or planting micro clover as you can see in the image below)
I fully understand that it’s hard to not be tempted by landscape fabric, especially if you are growing on a larger scale, or trying to expand your growing space. But if you can, see if you can shift away from using landscape fabric (and instead practice mulching as a way to reduce weeds which sporting your soil health). If you do use landscape fabric, wherever possible, replenish the soil at the end of your season; a good application of well-made compost and/or AEM’s are great ways to bring some balance back into the garden.
The tulip bed
Paths are planted with micro clover, beds are heavily mulched with leaves