We McSisters love our gardens. In the last few years, I have learned how the plastic industry found its way into our gardens. In this blog, we are only addressing home gardens. Plastic use in industrial agriculture is a huge topic itself.

One of the most important aspects of gardening is caring for the soil the plants are grown in. The time-honored way is to use mulch. Mulching is used to suppress weeds, improve moisture retention, enrich the soil with nutrients, regulate soil temperature, prevent soil erosion, and make a healthy environment for earthworms.

The two most popular methods of mulching are organic and inorganic. Inorganic mulch includes fabric weed suppressant, black plastic sheeting, and crushed rock. Organic mulch includes chopped leaves, manure, straw, grass clippings, newspaper and compost. So which form of mulch should we use in our garden?

You can guess that we McSisters would not choose to use plastic mulch in our gardens. It creates excessive heat that can kill certain crops. It doesn’t provide nutrients for the soil. As we know, neither fabric weed suppressant (made of plastic) or black plastic sheeting biodegrade. It doesn’t let air and water penetrate the soil, so roots don’t get water and oxygen. It becomes brittle and falls apart making for very unattractive ground cover. It’s useless to apply organic mulch because it won’t penetrate the plastic.

Organic mulch, on the other hand, contributes to your soil’s health.  It suppresses weeds, it helps to retain moisture and guards against erosion. Unlike plastic, organic mulch breaks down thus adding nutrients, making your soil healthy. And it has the benefit of making your yard look attractive.

I have had many gardens in the last 40+ years. Although presented to me as an alternative, never in those 40 years did I put sheets of plastic over the ground around the plants to prevent weeds. I thought, with no scientific knowledge, how silly. How can the soil breathe and get moisture and be nourished if you put plastic over it.  

When we bought our house 12 years ago, most of our entire property was covered in black plastic for landscaping. A peach tree on the property was a little sad, so I wanted to apply organic fertilizer.  Couldn’t do it because the plastic was covering the roots under the canopy. I experimented with growing both pumpkins and zucchini in other areas of the yard that were covered in plastic. No luck. The soil was basically dead from lack of water and nutrients.

A few years ago, we finally pulled up the plastic and, no surprise, the soil didn’t look very healthy. We applied lots of good organic soil to the area and grew some cool stuff, but found ourselves struggling to deal with weeds.  So, we decided to do something about it without the use of plastic. To prevent weed growth, we dug up the entire planting area, down a few inches to get out the old root systems, which largely contained weed roots.  Then we put down a couple of layers of cardboard sheets watering each layer well before applying the next layer.  Finally, we covered with 6-8” of new soil. On top of the new soil, we applied a good layer of mulch to deter weeds and conserve water.  It’s been a few months now and we have NO weeds!!

Now, at least in California, is the perfect time to plant those perennials and bulbs you’ve always wanted to show up in the spring. Make it a plastic free (and pesticide free) garden.

What can you do?

• Plant an organic garden

• Research organic vs inorganic mulch

• Research where to get mulch in your area

• Learn about the work of J.I. Rodale who pioneered organic gardening https://rodaleinstitute.org/

• Learn about composting and cover cropping

Websites with tips to get you started with organic mulch:

https://www.gardeningchannel.com/organic-mulch-options-garden/

https://www.gardenbetty.com/mulch/