Preparing for a Bog Garden

We had only 45 minutes of sunshine in Sydney last week.  The local rain gauge says we've had 137mm since the start of the month, more than one-and-a-half times the average.  That's La Nina for you!

There's a new garden bed between my newly-concreted driveway and path.  Well, there would be if I had added any soil to it -- it's just clay and a few weeds.  And 137mm of rainwater.

Our builders came back this week to deal with a few issues and The Geek was solemnly warned that this reservoir so close to the house was a Bad Thing, because the house is downslope. Initial excavations today have revealed some thin concrete inside the bed, which may have reduced the speed at which this water drains into the subsoil.  I am not hopeful that we can keep the area dry in the long term.

 This water is runoff from the driveway.  We are going to have a recurring problem here.  The subsoil is clay and if the soil is saturated, the excess water has nowhere to go.  If I were to mound up a garden bed on top of it, either the soil would wash away or the plants would drown.  I am going to have to allow for temporary flooding but want the excess water to be taken up by plants.  Now how does a frog habitat sound? 

What do frogs need?

• Most common frogs don't require standing water; temporary ponds are enough
• If there is a pond, it should have gently sloping sides as not all frogs can climb
• Frogs need plenty of cover: shrubs, logs, tussock plants and so on
• They frequent moist, shaded areas and can roam some distance from water sources

 What do tadpoles need?

• Tadpoles do need some water
• Tadpoles need water that isn't entirely shaded -- they eat algae, which grows in sunlit water
• Tadpoles need oxygenated water.  Duckweed and Azolla tend to decrease oxygen levels and will need to be removed.
• Tadpoles also eat the fungi and bacteria from decomposing plants
• Tadpoles are sensitive to manure

What do people need?

• Not to have frogs singing under their bedroom windows.  This location is away from our bedrooms and not too close to the neighbours' bedrooms either.

My plan is to create a dished depression in the middle of the triangle, add some leaf-litter and shelter, then plant the whole area with bog plants.    I imagine clumps of sedges at each corner as markers for people using the paths.  Nobody wants to fall into a bog, garden or not!

 The Australian Association of Bush Regenerators has put together a list of Frog-friendly Sydney plants here. I am particularly interested in these ones, as they are known to grow in my area:

• Hydrocotyle peduncularis (Native Pennywort)
• Persicaria decipiens (Knotweed)
• Knobby Club-Rush (Isolepis nodosa)
• Common Rush (Juncus usitatus)
• Mat Rush (Lomandra longifolia)

Stay tuned!
If you are interested in encouraging frogs into your garden, I can recommend the following websites:

• FATS, the Frog And Tadpole Study Group of NSW
• The Frogs Australia Network has plenty of information for Australians about frogs. 
• The Backyard Buddies programme helps children identify andd conserve local wildlife of all sizes.