Mulch color important?

[JayPoc]

A few years back I started mulching my mater patch. I've been thrilled with the benefits (no weeding, water retention). I use the cloth weed barrier type stuff and cover with about 3 inches of BLACK wood-chip type mulch.

So, I got to thinking...I wonder if I'd be better off in the future using a lighter color to reduce the soil temp a bit? It seems like it could make a difference. My climate is not all that hot. Typical July/August temps would be in the mid 80s during the day and 70s at night. We can count on a few short stretches in the low 90s. Humidity is rarely very high.

What do you think? Am I over-thinking it, or might a lighter mulch color be better?

[rainbowgardener]

Well to start with, if your day temps are mid 80's and your night temps are mid 70's then your soil temp is probably averaging about 80. That is about a perfect temperature for tomatoes and peppers, so I am not sure why you would want to reduce the soil temp. I have no idea how much difference it would make to use a light colored mulch (like what? I can't think of much that would be pale enough to make a difference. Shredded paper might start out white, but doesn't stay that way long.)

The plant catalogs sometimes sell red plastic mulch. Supposed to reflect light in wavelengths that the tomatoes like on to the plants or something. I tried it one time and I couldn't tell that it made a difference. And now I wouldn't use plastic anyway; I prefer organic mulches that let everything breathe more and break down to feed the soil.

[JayPoc]

That is about a perfect temperature for tomatoes and peppers, so I am not sure why you would want to reduce the soil temp...

I'm just guessing that as the mid-day sun beats down on that black mulch, the temps on the surface of the mulch would be much higher than the ambient air temp...probably well over 100 degrees. How deep that sort of heat would penetrate is the question, I guess...

[rainbowgardener]

You could check with a soil thermometer. I'm guessing that the wood chips do not heat up the way other materials might and do not pass the heat along very much. If anything the presence of the mulch, even though black, might keep the soil cooler.