Creating a Frog Bog

Australia is blessed with a unique frog diversity, and is home to over 200 frog species, with 10 frog species local to the western basalt plains.

Unfortunately frog populations are depleting at an alarming rate – 43 of our frog species’ are listed as endangered or vulnerable, and three are presumed extinct.

The biggest reason for the decline is the loss of habitat due to housing development.

So when Betsy-Sue drew up the design for our backyard, I asked her to include an area for a frog bog. I wanted to give the local frogs somewhere to go and be happy little hoppers!

Frog Bog basics

For frogs to thrive, they need moisture, food and shelter – just like we do!

Ideally, a frog bog should be located in an area of the garden that receives shade and some sun (about 70% shade and 30% sun). In our garden, the perfect area is on the right side of the house where only the morning sun comes through.

Beside the alfresco area we planted an acacia bush quite some time ago that is now at ceiling height. The bush provides a lot of shade, and I noticed last Summer that it’s a very cool spot to wander through.

The shade from the acacia bush will ensure that some algae grows, which is necessary for happy froggers, and the fallen leaf litter will provide sustenance for tadpoles that may come along.

As well as shade and water, frogs also need dedicated areas adjacent to the bog where they can hang out! Rocks, logs, leaf litter and appropriate plants will keep the frogs happy.

The last consideration is noise. Frogs can be pretty loud croaking and singing all night, so it goes without saying the bog needs to be neighbor-friendly. We don’t cause any unnecessary issues or disputes!

The frog bog design

Below is the design Betsy-Sue drew up and the plants recommended for the area.

Construction

We decided not to go to the effort of creating a natural bog. Instead, we purchased a kids ‘clamshell’ sandpit/pool from the local Big W. It cost about $20, which is far cheaper than buying one of those expensive custom fiberglass ponds.

The clamshell was sanded lightly and then spray painted black. We did this so the water would be reflective otherwise we would still see the bright green and it would ruin the overall effect.

Once the clamshell was ready it took a few minutes to dig the hole and put it into position.

I added some logs and basalt rocks, that I had salvaged from cleaning up the front yard earlier this year, around the edge and in the pond. Frogs aren’t actually swimming all the time, so you need to have something for them to climb onto to get in and out of the bog. The log I added wasn’t a very ‘heavy’ one, so I ended up putting a brick in the water to weigh the log down. That’s ok as it adds a layer under the water.

The final step before adding plants is to fill the clamshell up with water. Filling up frog ponds can be a bit tricky because our tap water is chlorinated. To allow the chemicals to dissipate, the water needed to stand for a good 5 days with nothing else in it.

Plants

Frogs and tadpoles need a variety of plants, both in and out of the water. The plants need to be local to the area and include shrubs, grasses, ground covers and water plants. These plants not only offer shelter and food for tadpoles and frogs, but also attract insects and bugs.

Unfortunately the plants listed in Betsy-Sue’s design, whilst indigenous to the area, weren’t available at the local native nursery. But after asking the nursery assistant we came away with 4 alternatives that will do just as well:

  • Craspedia paludicola – ‘Swamp Billy Buttons’
  • Ornduffia reniformis – ‘Running Marsh Flower’
  • Myriophyllum crispatum – ‘Water Milfoil’
  • Gahnia filum – ‘Chaffy Saw Sedge’ (replacing the carex gaudichaudiana)

The billy buttons and marsh flower will eventually have yellow flowers that will look attractive. The sedges at the back grow to about 1 meter high and wide.

I also want to add some extra color in the bog using ‘Lythrum salicaria’ (Purple Loosestrife). Lythrum has purple flower spikes in summer and looks really pretty, but I need to wait a couple of months before they are available at the nursery.

Around the side is some ‘River Mint’, a groundcover herb that can be used like mint, and a saltbush. These will provide areas beside the pond for frogs to wander around in and shelter.

I also added a solar light to the side of the pond. I’m hoping the light will attract some insects at night for the frogs to eat. It also looks pretty when walking past the alfresco door at night.

Will it work?

They say that if you build it, they will come.

It’s been a week since I added the plants and there hasn’t been any action yet. But here’s hoping. I’m looking forward to hearing the first frog call come from the bog – that will be a very satisfying moment for me knowing I have create a habitat garden.

Out of the frogs local to our area, below area the species that I think we’ll eventually hear in the frog bog:

  • Southern Brown Tree Frog
  • Growling Grass Frog
  • Eastern Common Froglet
  • Eastern Banjo Frog/Pobblebonk
  • Spotted Marsh Frog

The hard part will be to get a photo of them out and about, or an audio clip of them making noises. I may need to figure out a time-lapse deal thing with the GoPro.