Favourite Bog Plants

Bog gardens are wonderful places – a no-man’s-land where the watery world of the pond meets the rest of the garden – and picking the right plants can make all the difference to how everything all comes together.

With so many different suitable varieties available, anyone thinking about planting a bog garden can sometimes be spoilt for choice, so here are some old favourites which are guaranteed to be winners, whether you’re looking for early flowers, a splash of summer colour, or a magnet to attract wildlife.

Good plants for early flowering are…

1. Marsh Marigold

Although strictly speaking it’s a marginal, the native (Caltha palustris) is a long established favourite for the bog garden. In April, its lush dark green foliage and showy yellow flowers, which look like huge, waxy buttercups, bring an unmistakable blast of early colour to the pond edges and kick-starts the water garden’s flowering season.

Cultivated forms include C. palustris ‘Plena’, an attractive variation with prolific double flowers that make it look like a mini yellow pom-pom Chrysanthemum, or the ‘Alba’ variety, which – as the name suggests – has white flowers. A small pond plant in stature – at nine inches (23cm), it is only around half the height of the wild form – ‘Alba’ makes an ideal bog plant for the smaller site, while for larger ponds the giant of the family, C. polypetala, is well worth considering.

2. Monkey Flower

Monkey flower Mimulus, is another group of marginal plants that do well in the bog garden, bringing a display of small, snap dragon-like flowers to the pond during the summer. Yellows again tend to be the favourite colour scheme, with the likes of M. luteus and M. guttatus – which are both to be found in the British countryside – being fairly typical examples, growing to a foot (30 cm) or so in height.

The taller, purple-flowering M. ringens is well worth including for a little variety if space allows; this plant prefers the wetter end of the bog garden, and will happily tolerate year-round submersion, while M. cardinalis and cupreus will not, making them the true bog garden candidates of the Mimulus clan.

Some plants to add more colour…

1. Astilbe

Often encountered in the herbaceous border, Astilbes are one of the best bog plants of all. Low maintenance perennials, they offer a striking architectural shape, with fern-like foliage supporting dense, feathery plumes of tiny, but prolific flowers in the summer.

There’s an Astilbe to suit just about any planting scheme, with most popular kinds tending to be the colourful varieties of A. arendsii – the likes of the red ‘Fire’ and ‘Fanal’ cultivars, the pink ‘Bressingham Beauty’, liliac-pink ‘Amethyst’ and the white ‘Deutschland’ and ‘White Gloria’.

All of these varieties grow to around two to three feet (60 – 90 cm) tall, and spread to about half as much in width. They look at their absolute best in a mass of waving foliage, but even as a lone example where space is an issue, a well chosen specimen is hard to beat – and there are even some dwarf varieties available, such as the suitably named A. crispa ‘Lilliput’ or A. simplicifolia ‘Sprite’, so no bog garden need be without these showy plants.

2. Day Lily

Day lilies (Hemerocallis) are firm favourites for the moist soil of the bog garden, with a long flowering period, from June or early July through to September. As their common name suggests, each individual bloom only lasts a single day, but since they produce new buds continually throughout the season, the plant is never without a show of trumpet-shaped flowers.

There are many species and thousands of cultivars to choose from, with numerous hybrid forms having been specially bred to give the gardener the widest possible range of colours and sizes, from dwarf forms little more than one-foot (30 cm) high, right up to four foot (1.2 metre) monsters. The original ‘type’ form of this plant typically has dull reddish yellow petals, but now varieties such as ‘Pink Damask’ and ‘Luxury Lace’ (lavender) provide a much wider choice, cementing this useful plant’s place in any list of top candidates for the bog garden.

Planting to attract wildlife…

1. Creeping Jenny

The versatile native Lysimachia nummularia, is a great ground-cover plant around the pond, growing dense two-inch (5 cm) tall mats of sprawling fresh-looking foliage, which sprouts a profusion of yellow, star-shaped flowers from June to August. It’s a particularly useful species to use under taller bog plants, helping to reduce any unwanted growth and slow down evaporation from the soil, while also softening the edges between the bog garden and the pond itself, with its floating leaves. This makes Creeping Jenny a particularly useful addition to the wildlife pond, since its shoots provide plenty of hiding places for amphibians and other small, damp-loving species, as well as forming a good way in and out of the water for them.

2. Purple Loosestrife

This striking native wildflower is excellent for the wildlife bog garden, attracting bees and butterflies with its nectar-rich purple/red flowers, providing a valuable food source for hawk moth caterpillars, and offering an ideal overwintering home for insects amid its dense foliage.

The wild form of Lythrum salicaria can make around six feet (1.8 metres) in height, which means it can be a bit too big for some gardens, but smaller cultivated varieties are now available – such as ‘Beacon’, ‘Firecandle’ or ‘Robert’ which grow no more than half as tall. Alternatively, the related Wand or Rocket Loosestrife (Lythrum virgatum) is even smaller, which may appeal to gardeners with smaller sites to fill, though it has a bit of a reputation for being invasive, so it may need to be kept under control if conditions suit it too well!

There are plenty of other well-known bog garden favourites, of course – from hostas and irises to lobelias and giant rhubarb – so whatever planting scheme or overall ‘look’ appeals you’re sure to find something that fits the bill. After all, it’s your bog garden; enjoy planting whatever you like best yourself.