I would like some information about using plastic to cover your garden to cut down weeding.

Question

What kind of plastic? What plants would benefit from this and what plants wouldn’t?

Answer 1

Plastic is used to kill weeds before planting through a process called solarization. It is not recommended for suppressing weeds in an established garden for 2 main reasons. One, it prevents air, nutrients and water from reaching plant roots and, two, it can cause serious over-heating of soil and plant roots. If using plastic to solarize or kill weeds and weed seeds, cut it into workable strips and overlap the strips by 2 inches. Black plastic heats up in sunlight so it is favored. By blocking all sunlight, it also makes weed seedlings die from lack of light for photosynthesis. To kill stubborn weeds and their seeds already in the soil takes one whole growing season. If you use plastic between vegetable rows, cover it with an organic mulch, straw or wood chips once soils have warmed to get the plastic in place. A wood chip layer of 6-8 inches suppresses weeds. The advantage of organic mulch is that it breaks down and nourishes the soil. Consequently, it needs to be “topped off” every year and this gets expensive. You don’t say if this is a perennial or vegetable garden. In early spring, plastic is sometimes used to increase soil temperature. Since it will cut down on rainfall reaching roots, drip irrigation is recommended. I certainly would not use it for cool season crops like lettuce, peas, spinach and cilantro. They don’t do well when the soil gets too warm. Here is more info on inorganic (plastic, rock, etc) mulch choices. The first one is entirely about using plastic: https://content.ces.ncsu.edu/using-plastic-mulches-and-drip-irrigation-for-vegetable-gardens
https://www.gardeningknowhow.com/garden-how-to/mulch/using-inorganic-mulch-in-gardens.htm