On Thu, 31 Jul 2008 19:43:03 +0100, Spider wrote
(in message ):

Hi,

I've read the exchange between you and Sacha. Sacha's idea of an avenue or
concentration of hydrangeas is lovely - I've seen it done to great effect.
You will undoubtedly want more! If you go down this route, it makes the
sub-terranean reservoir method of watering more worthwhile. To all intents
and purposes, what you saw on the BBC gardening prog was a simple bog garden
but with more drainage. Please don't mistake me and build a bog garden, as
this would be too wet, but follow the general principles: a) dig out deep
depression b) line with strong plastic or butyl liner c) make holes to
allow *some* drainage d) backfill with soil e) plant your hydrangeas.
Having done this, if you subsequently think the area is too wet, simply use
a garden fork to make more holes.

That makes sense.

I wonder if carving a basin into the clay subsoil would be useful. About a
foot down the soil turns into solid yellow clay, and a depression dug into
that will hold water indefinitely- well until it evaporates. Maybe I could
make a small reservoir there under the plant, something for it to dip its
roots into for a drink when its roots have grown that far, say maybe after a
year, somethng like that.

And meanwhile the plastic sheet "bog garden" technology would help.

If you only want the one plant, you could add some water-retaining
gel/crystals to the planting hole and the soil you back-fill with. You
could also bury a length of pipe next to the plant to guide water to the
roots of the plant. This will encourage the roots to grow down, rather than
stay near the soil surface where they may linger if you water normally.

Mulching is, of course, a great help - but not with a marble slab if you
want to encourage blue flowers.

Yes, I did wonder about that....

A seep hose (what Sacha was describing) is a good idea, too, but its
efficacy may suffer if the soil compacts, just as with normal watering. One
solution to this may simply be gently forking over the soil periodically.

Spider

Ok- thanks!

--
Vacutone