The edged and planted bog garden

How to create a bog garden

Boggy areas are excellent for encouraging more wildlife into your garden. They’re particularly good for amphibians and insects. But if your garden isn’t on the edge of a stream, how can you create such an area? The answer involves rather a lot of digging.  Dr C and I like a bank holiday project, so that’s what we set out to do at the beginning of May.

You will need:

  • Somewhere to create it
  • A spade
  • A tarpaulin to put the soil on
  • Pond liner or other sturdy waterproof membrane big enough to line the pond (this is a useful calculator to help you work out how much you will need)
  • Water (preferably rain water from a water butt)
  • Perennial plants suitable for boggy or moist areas (see below for how to pick them)
  • Some logs or stones to edge the bed, hiding the pond liner

1. Pick your site

In the wild, these sorts of habitats often occur next to streams or ponds, so we chose to create ours next to our barrel pond. If your pond is level with where you want to create your bog garden, you can create a beautiful uninterrupted effect. That wasn’t an option for us, but being next to the pond will make life easier for the frogs and insects.

A pond isn’t a prerequisite for a bog garden (and if you can’t have a pond, a bog garden is a good alternative). But ponds are brilliant for all sorts of wildlife, even if they are tiny, like ours, so do consider creating one – it’s another very satisfying weekend project.

2. Mark out your bog area

You can use pegs and string to mark it out, or, like us, mark the edges with spade cuts. We went for a curved shape to match the shape of the pond.

3. Start digging

Once you’re happy with the shape and size of the bed, start digging. This is the time consuming bit. You’re aiming for a straight sided hole 50-60cm deep. Dr C did most of the hard work (as usual), but I did enough digging to ache all over for the next few days.

First we took off the turf, using it to thatch the hedgehog house. Then the serious digging starts. How hard this stage is depends on the type of ground you’re digging. In our case, it was pretty tough, as the ground under our lawn seems to be 60% building rubble. We dug up bricks, paving slabs, carpet and even a buried pipe (not connected to anything, thankfully), as well as a load of stones, and plenty of earthworms. It felt like we were on a Time Team excavation, digging up the inevitable small wall.

The bog garden hole
The bog garden hole
The soil and rubble from the hole (note the pipes and paving slabs)
The soil and rubble from the hole (note the pipes and paving slabs)

4. Line your hole

After trying to get rid of any sharp stones on the edge and bottom of the hole, we put a layer of sand on the bottom, to try to prevent anything piercing the lining. We then put the pond liner in place, pushing it into the corners of the hole, then trimming generously. We then stabbed a couple of small holes in the bottom, to allow water to drain away slowly. From what I have read, the general recommendation is a garden fork’s worth of holes per square metre. Our hole was about half that, so we went with 2 holes. The more holes you make, the faster it will drain and the less boggy, but you will need some drainage.

We added a layer of sand to the bottom of the hole to protect the pond liner
We added a layer of sand to the bottom of the hole to protect the pond liner

5. Fill in the hole

Time to undo all that hard work. First add a layer of smoothish stones, to prevent the holes becoming blocked by soil.  Then chuck all the soil back in your hole. We also added some compost, but you could also add some manure.

Filling the lined hole back in
Filling the lined hole back in

6. Water

We watered the new bog garden bed with a couple of cans of water, then let the soil level settle overnight, before topping up with soil then watering and letting it settle for a few more hours.

Leave the filled hole to settle
Leave the filled hole to settle

7. Trim and edge

Trim the pond liner more neatly, and tuck it away. We used a mix of logs and stones to edge the bog garden. These make it neater, hiding the pond liner, and provide some good hiding places for small creatures.

8. Choose your plants

I chose a mix of native plants that like boggy or moist ground. My selection includes a variety of flower shapes, colours and flowering times, to try to provide food for as many difference insects as possible. I also chose a mix of heights.  The plants I went for are:

  • Devils bit scabious
  • Water avens
  • Loosestrife
  • Marsh marigold (otherwise known as kingcup)
  • Meadowsweet
  • Marsh cinquefoil
  • An iris (a relative of the native yellow flag iris, but smaller and blue)
The edged and planted bog garden
The edged and planted bog garden

If you’re in the UK, here are a couple of nurseries that specialise in pond plants and have a good selection of native species (and do mail order):

How it’s going so far

The plants seem to be settling in well – we’ve had flowers from the meadowsweet and marsh marigold already. An insects seem to enjoy it. Next door’s kittens also seem to enjoy walking along the logs at the edge, so I hope amphibians will avoid it until the plants provide more secure cover…

Advertisements

One thought on “How to create a bog garden”

What do you think?

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s