From

Location

Message

Date Posted

Caceres, mid west of Spain

As my summers are warm and dry I think a lot in refreshing the plants and the whole patch. One of my last thoughts is concerned with the mulching subject. If you want to save water, it is fine, but not as good if you are looking for a cooling effect.

As mulches reduce evaporation, and evaporation has a clear cooling effect, I have to conclude that mulches reduce refreshment of the plant and the soil as well. Is truth that they shade the soil and prevent the sun light heat it up, but as long as the day goes ahead, the soil is being warming and not refreshing, and so, in the afternoon and evening a mulch soil can be warmer than a nude one, over all if the nude one is damp. The effect on plants have to be bigger because the mulch doesn't shade the plant leaves and vines.

Of course I am talking about garden soils with a correct humidity level and cake texture. If you walk on foot crossing a sandy beach of Southern Spain at noon in mid July, you will notice what is a hot soil like.

Maybe I’ll make a little experiment to test my hypothesis, just mulching one plant with straw and don't do it with a neighbour plant and set a thermometer at 5-10'' over the soil near the plant. The thermometer will be put under a little shade just at the testing moments and then take it out with its shade in order to not interfere on conditions.

Don

5/24/2003 1:32:15 AM

Nova Scotia

sounds like a good experiment. let us all know of your results.

5/24/2003 9:14:10 AM

Topsfield, Ma.

Don, I've mulched my 1200 sq ft patch for the last 4 seasons with 4-6" of shredded leaves w/o any problems.
Pumpkins keep getting bigger, organic matter around 18% and rising every season, and more time for sippin' coldies instead of weeding. Just my 2 cents worth ! Duff

5/24/2003 7:41:51 PM

Caceres, mid west of Spain

I won't pay you your 2 cents Duffy, and it is because I believe that summers in Topsfield, Massachussets are not the kind of dry hot summers where evaporation cooling effect is really necessary.
In your climate mulching has to be fine for sure, as you say; you only have to take a look at you woods soil to believe it works well there.

Don

5/25/2003 1:21:26 AM

syracuse, ny

concerning reflected as opposed to absorbed heat in this case, howsabout a couple of digital thermometers with their probes inserted at exactly the same point and depth on the same plant, one inserted into the mulched test area and the other into bare, reasonably moist soil of the same moisture content as the other...then you wouldn't have to grow or majorly modify another plant, and/or it would only require a small sample area.
something else to try as part of the experiment would be a
good-sized piece of aluminum foil placed over one of the test areas, just to see the effect(s) of REFLECTING AWAY
the sun's rays, which are, essentially, the 'problem' here.

i have read that this may have an adverse, good for us effect on insects as well, such as possibly the cucumber beetle. as was said, let us know of your findings! 'pal

5/27/2003 7:35:24 PM

syracuse, ny

PS--the insects become confused from the reflected light coming up through the plant and don't know what's going on, so they
go on to someone else's squash patch.....lol

5/27/2003 7:37:44 PM

Riverton, WY

Don, Mulching works well in my climate, but it's essential for me to wait until the soil warms up in early July. The temperatures in July consistantly hit 95 with night lows around 60... a 35 degree temperature swing. Those 95 degree temperatures are often accompanied by 20-30+ mph winds & 10-15% humidity. I mulch with about 1 inch of compost which moderates the soil temperature, & supplies a constant source of nutrients. I've learned MANY times over the last 10 or 15 years that I have to wait until the soil warms up before I begin to mulch. (I'm a little hard headed sometimes! LOL!!)

5/28/2003 12:28:55 AM