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

Chris Hogg wrote in message
...
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

Hi Chris,

I have the first type of bog garden. It's fairly good, but can dry out in
summer and definitely needs help from a hose. Next time, I will try
puncturing the liner further up the sides, leaving a basal reservoir. I get
around the sour soil problem by putting in a layer of charcoal near the
base. It seems to work. I used barbeque charcoal as it is much cheaper
than aquarium charcoal, and more readily available. You may be lucky with
the autumn approaching, as many suppliers may be selling off their stocks at
silly prices.

I've no doubt that the second type of bog garden is more reliable as far as
moisture-retention is concerned. However, you will need to be careful when
feeding plants in the bog garden, otherwise you could contaminate the pond
water. Of course, the charcoal solution will be just as effective against
sour soil here as it is in the first type of bog garden.

As to soil, I used ordinary garden soil improved with bagged compost.
Because my soil is heavy clay, I used composted bark (Westlands) to help
break up the clay, but your garden soil may be good enough on its own.

Spider

On Wed, 31 Aug 2005 20:28:57 +0100, "Spider"
wrote:




Hi Chris,

I have the first type of bog garden. It's fairly good, but can dry out in
summer and definitely needs help from a hose. Next time, I will try
puncturing the liner further up the sides, leaving a basal reservoir. I get
around the sour soil problem by putting in a layer of charcoal near the
base. It seems to work. I used barbeque charcoal as it is much cheaper
than aquarium charcoal, and more readily available. You may be lucky with
the autumn approaching, as many suppliers may be selling off their stocks at
silly prices.

I've no doubt that the second type of bog garden is more reliable as far as
moisture-retention is concerned. However, you will need to be careful when
feeding plants in the bog garden, otherwise you could contaminate the pond
water. Of course, the charcoal solution will be just as effective against
sour soil here as it is in the first type of bog garden.

As to soil, I used ordinary garden soil improved with bagged compost.
Because my soil is heavy clay, I used composted bark (Westlands) to help
break up the clay, but your garden soil may be good enough on its own.

Spider

Thanks Spider. Charcoal seems like a good idea. I don't think I'll be
using any fertiliser though; AIUI most bog plants prefer a soil low in
nutrients. But the wider point, that anything applied to the bog
garden will leach into the pond, is something I'll bear in mind.


--
Chris

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