I'm planning a pond and adjacent bog garden, hopefully for
construction next year. I've seen two ways described of making the
latter. The first simply involves burying a membrane in a
saucer-shaped depression, and relying on the inhibited drainage to
keep the soil moist, with occasional assistance from a hose.

The other type is in effect an extension of the pond itself. A hole is
excavated the size of the pond and bog garden combined, with the bog
garden rather less deep than the pond part. A single membrane is used
to line both parts. A 'leaky wall' is then built over the membrane,
dividing the pond part from the shallower bog garden, and the bog
garden section refilled with earth.

My inclination is towards the second design, but has anyone had
experiences of either that they'd care to share? Is there a preferred
type of soil for bog gardens, or does ordinary garden soil do? (I'm
keen to grow candelabra primulas and moisture-loving lobelias; our
existing soil is acid). How do you stop the soil in the second type of
bog garden I described from becoming sour, as it will be permanently
wet?


--
Chris

E-mail: christopher[dot]hogg[at]virgin[dot]net