This spring I picked up some red mulch plastic for use under my tomato plants. The claim is that the red mulch reflects a spectrum of light that helps tomatoes grow. I was skeptical, but since the claim was being made by Lee Valley, which in the past has never steered me wrong, I thought I’d give it a try. I used the “super red mulch” ( http://www.leevalley.com/en/garden/page.aspx?c=&cat=2,2300,33272,10532&p=10532) and planted 2 rows of tomatoes with the mulch and 2 rows without as a control. The two adjacent rows of plants were planted the same day, are the same variety, and have had the same amount of water, fertilizer, etc. I punched quite a few holes into the red mulch to try to allow as much water as possible to make its way into the soil. There is a noticeable difference with the tomatoes that use the red mulch.
- The plants overall are shorter and fuller (its hard to see this in the picture so I drew a red box around the average height of the tomatoes with the red mulch and a yellow box showing the average height of the non-mulch row)
- The tomatoes on average are larger and yield is higher
- The tomatoes are ripening a couple days faster