The benefits of a water-based garden are numerous –from attracting wildlife, to providing an environment for different types of plants that you might otherwise not be able to accommodate. However, you may wish to build a pond in your garden and the presence of small children or animals does not permit it.
Bog gardens are an excellent alternative in this respect, as flooding deep enough to pose a threat of drowning would not sustain many of its staple cultivars.
You could opt to fill in an existing leaky pond and plant it up, but if you are creating a bog garden from scratch, you should aim for an area that gets full sun, although some pockets of shade are acceptable. The size is entirely up to you of course, but you should dig down at least 45cms to allow plants to form good root systems.
If you’ve decided to convert a section of lawn for your bog’s location, then you can save on lining materials by recycling the existing turf. Simply cut sections using a spade and lay them butted up, grass side down into the bottom of the hole.
If this is not the case then you can either use standard butyl or plastic liner as you might in a pond, or, if you don’t mind getting your hands dirty (which as a gardener I assume you don’t), then you could line in a more traditional manner with wet clay. If you are using pond liner, pierce it at every metre with a pitchfork to allow for drainage and weigh the edges down with bricks to prevent it shifting underfoot, but whatever the material, your liner should fall at least a few centimetres below the rim of the bog so that excess water can escape over the top. (Don’t trim it though until you’ve partially filled with soil, as the weight of the soil will pull it down in the hole).
Put a layer of gravel in the bottom and then you can back-fill with your excavated soil after removing any weeds and large stones. If your soil is poor you can add a little organic matter to give your plants a good start.
Finally, you come to the key ingredient of the bog – water. Ideally a bog should be filled with rainwater to ensure a minimum of detracting chemicals, so, if you have a rain barrel or a friend with one, now is the time to use it. If this is too impractical then regular tap water will suffice, however, it will be most effective if given a few days to stand and evaporate its chemical element.
With your lining, base soil and water established, you ought to allow a day or so for the soil to settle and then crack straight on with the planting phase. Below you’ll find a small group of our favourite suitable candidates for this purpose.
Floral & Hardy’s Five Favourite Bog Plants:
Astilbe is a clump-forming herbaceous perennial with feathery flowers of pink, white or red in summer. Its young foliage has a bronzy appearance turning dark green through summer and autumn, while those flower heads will turn brown and remain attractive later in the year.
The ‘Umbrella Plant’ is a vigorous perennial that forms large clumps of rounded green, and then pink, foliage that will show in summer and autumn respectively. They also produce clusters of pink, star-shaped flowers in the spring.
The ‘Giant Rhubarb’ is a large, bold, herbaceous perennial sporting huge green leaves for most of the year, and red russet blooms throughout summer alongside its Christmas hued fruits. A spectacular, architectural plant, but suited only to the larger garden as it can reach a height of 2.5metres in a single season and a spread, over time, of 4 metres!
Ligularia dentata ‘Desdemona’
‘Desdemona’ will bloom with daisy-like, bright sunny orange flowers with lance shaped petals springing from a deep red inflorescence. Its foliage will appear bronze, purple and green from spring to autumn and its colours should tower around a metre above the waterline of your bog.
The ‘Arum Lily’ can be a deciduous or semi-green perennial forming emerald-green, lance-like leaves around a hooded white flower with funnel appearance. These will bloom in early summer are followed by orange fruit in the autumn.
By Josh Ellison