I would like to know what is the benefit of using clear versus diffused plastic covering on a greenhouse.
There are many benefits to using a diffused plastic covering for a greenhouse.
Clear panels deliver direct light while opaque panels provide diffused light. If you want to germinate seeds and grow starters which will be transplanted outdoors, then a clear covering has the advantage of bringing full, direct light to the starter trays. This warms the soil and encourages germinating seeds to sprout and develop into a vigorous starter plants for transplanting.
If you plan on growing the plants to maturity in a greenhouse, a diffused covering has the advantage of providing even light for balanced foliage growth as well as preventing hot spots within the greenhouse.
While it may seem counterintuitive, diffused light provides superior light for growing plants. Diffused light may appear to be less bright than direct light, but the light that generally produces the most efficient photosynthesis is not visible to the human eye. Diffused light reaches plants from many angles, so plants do not get ‘leggy’ as they would when competing with each other to grow towards available light. With diffused lighting plants develop a more balanced, compact structure.
If you want a dual-use greenhouse, the semi-diffused cover provides the benefits of both clear and diffused covers. The semi-diffused covers allow enough “semi-direct” light for seed propagation in early spring, and once the starters have been set out, the greenhouse can then be used to grow full-term crops inside. The semi-diffused covers provide an all-purpose greenhouse.