Last week we looked at black plastic so this week we are going to look at clear plastic. There are many similarities between the two but also some differences. 

Clear plastic can be used to warm the soil in spring as black plastic and should be removed to prevent the growth of fungus and other pathogens in the soil. Methane and other gases produced by the anaerobic conditions can build up under the plastic damaging plant roots. The better the soil (more fertile) or the higher the clay content, the greater the problems become as with all plastic mulches. 

Similar to black plastic mulches, clear plastic is generally applied as a one layer mulch. Clear plastic is available in different thicknesses, widths, and lengths. Some plastic mulches are produced with special properties like resistance to biodegradation from ultra violet light. There are more choices on clear plastic mulches that will biodegrade than with black plastic . 

First let’s examine some of the benefits of using a clear plastic mulch. It holds in heat and moisture, hence it helps to warm soil in spring. It works so well at trapping heat that it can be used to solarize soil. In fact, clear plastic will warms soil twice as fast as black plastic. Research has shown that clear plastic for solarization is as effective as the extremely dangerous chemical Methyl-Bromide for reducing soil pathogens prior to planting strawberries [HortTechnology July-September 1997]. It is best used and most effective in specialized applications. It has been found that translucent (clear) plastic reduces nutsedge more effectively than black plastic. 

As with all plastic mulches there are some drawbacks also. Since it is clear, it allows more light energy to reach the soil allowing weed seeds to germinate and grow under the mulch.