0tterbot wrote:
hello,

in retrospect, i am thinking now that it ended up being unfortunate
that we mulched with horse poo, rather than (say) straw, just before
a stint of (unseasonal for the area) hot weather with almost no rain.

knowing that dark colours are likely to absorb heat & lighter colours
to deflect it, i've been putting straw round the veggies over the top
of the poo (but as my plants are pretty well spaced, most of the bed
areas are still pooed, rather than strawed).

when i walk into the veggie garden, anecdotally at least (i haven't
measured due to a lack of a working themometer at the moment!!) it is
several degrees hotter there than in general garden areas (where the
larger plants would ease the effect with shading, transpiration & all
that stuff - but there are no larger plants in teh veggie garden -
it's just blindingly hot :-). between the rows the grass is short &
dry & therefore light-coloured, but the throb of heat you experience
walking in on a hot day is quite remarkable nevertheless!


There is also the cooling effect of water evaporation. Darker green lush
growth feels cooler than lighter dry growth because it is keeping cool by
evaporation.

i can't recall any previous time in my fairly limited gardening
experience where i've noticed that i seemed (personally) to have
created an inadvertant heat sink like this. the garden in general,
the veggie patch in particular, is struggling with lack of water atm
& it's just making me sad, really. i haven't been getting good
germination this spring/summer, nor good growth. there are things i'm
just not doing because i foresee that they would fail, & i should
just put it off until a cooler/wetter period starts up.
any thoughts or comments on mulch colour?
ta!
kylie

In principle a lighter colour will reflect more heat but I doubt the
difference would be great. It will still be fulfilling its main purpose of
insulating and covering the soil. In any I case it would be better than
none.

You could always apply a thin whitewash of lime ;-)

David