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…

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Rewilding: a utopian vision?

Up til now, I haven’t done much thinking about the idea of rewilding. The idea of returning large swathes of land to a state of wilderness, and reintroducing apex predators to help manage that biodiversity, instinctively appeals to me. I love the thought that lynx may, one day, roam free in Britain. That we may, one day, have wild spaces which nature manages, rather than man. That the balance between humans and wildlife is shifted to a more equitable arrangement. But is it too impractical to ever take place?

Last week I heard a fascinating talk from Peter Smith, one of the founders of the Wildwood Trust, and a keen proponent of the idea of rewilding. The talk is available to view on YouTube. It’s long, but I urge you to watch it.

I won’t try to repeat all his points here – you can listen to them for yourself. Instead, I’ll just share some of the things that struck me from his talk.

  1. Focus on the economic argument: conservationists are unlikely to convince politicians, businesses or even the general population about such a radical idea as rewilding by focusing on the ecological benefits. Peter Smith’s talk had a large focus on the economic case for rewilding. For example, he argues that rewilding would more than pay for itself through the flood prevention benefits it would provide.
  2. Reintroducing some species will lead to benefits for many others. For example, beavers create the right sort of habitats for a whole range of species, including water voles, otters, molluscs and bats. Reintroducing pine martens could help red squirrels. And Surrey would be a good place to reintroduce pine martens, as it has the right sort of habitat – lots of well connected woodlands.
  3. There is enough space: rewilding will require large areas of land. On a crowded island like ours, that can seem completely unfeasible. But looking into our land use reveals potential. In England, more land area is used for golf courses than for homes. And, throughout the UK, much of the land that is being farmed is unproductive land that would never be farmed if it weren’t for the perverse incentives of subsidies. Peter Smith argues that we don’t need to farm that land – we can feed ourselves without it.

He also presents some interesting ideas on how the taxation system needs to move away from taxing income to taxing land, to bring an end to a system that incentivises purchase of machinery rather than hiring of labour.

Rewilding is a wonderful, visionary idea. But will it ever come to pass? The trouble, as Peter Smith admits, is that the people who benefit from the current system, and have most to lose from the changes needed to bring about rewilding at a large scale, are the people with the most power. A massive proportion of our land is in the hands of a small number of people who make a large amount of money from the status quo.