This is a dumb question, I'm sure, but I'm going to ask it anyway. Can clay on a hillside be considered well draining soil?
If you really want to know for your particular hillside you'll need to dig a hole at least a foot deep, fill it with water and time how long it takes to drain. Usually well draining soil will drain in about an hour or two on a hillside. When I had clay soil in my last garden it could take hours to drain. No hillside, though. Here I have plenty of hillsides, sandy/rocky soil and it can drain in 20 minutes if it's not amended.
And no, it's not a dumb question. : )
Here's what Walter Reeves said in his column on making well drained soil:
"I was explaining to someone recently that flowering cherry trees absolutely require well-drained soil to succeed. "Well, thatÂs not a problem," they responded, "IÂm planting on a slope, so water drains right past it."
"Sloping soil is usually poorly drained," I replied. "Your cherry will be dead in a year if you plant it on that eroded clay bank."
It is important to distinguish between surface drainage and soil drainage.
Water inevitably flows down hill. That is surface drainage. Soil drainage, though, is what happens to moisture when it soaks through the earth around a plantÂs roots."
He goes on to tell how to amend the soil, here's the link.
Here is a link that might be useful: Walter on Soil Amending
Hi, Nell. I read his article. Do you know what he means by "soil conditioner"? I can't remember seeing a product with that name.
Soil conditioner sometimes called Nature's Helper.
Thanks, Nell. It appears to be sold in the south, but not in my neck of the woods.
Mary, I have fairly heavy clay soil. For plants that like poor soil (achillea, lavender), I do a mix of half clay, half sand. For those that need good soil that is sharp draining I do 1/3 clay, 1/3 composted manure, 1/3 sand.
Thank you for the good advice. I sort of thought that just planting in clay wouldn't be the best idea no matter where it was located. But I wasn't even thinking about surface drainage. I just thought that water wouldn't last in clay on a hillside like it does on a flat surface.
I think the soil conditioner that Mr. Reeves mentioned might be something like gypsum. I never added anything to red clay in No. GA except compost of some kind. If you mix GA clay with sand, you frequently get cement.