Bog pot


If you have not enough space in your garden for realisation of a great bed or if you have no garden, you have not to spare a longtime functioning raised bog. Realisation succeeds also in a substantial smaller scale. A suitable container is found quickly, a cement tub is likewise suited as a withdrawn, old laundry tub. Sole precondition is watertightness and a minimum volume of circa 40 litres. In this container you can create with little effort a longtime stable raised bog, in which numerous carnivorous plants can be cultivated all-year easily. Such a „mini-bog“ is doubtless an enrichment for each balcony, terrace or front garden.

Construction and care

As already mentioned, each watertight container is suited, if it features at least circa 40 litres volume and a minimum height of circa 20 centimetres. Fundamentally and as secret of success, namely to create a longtime stable and with little care managing-with bog, is basic construction of the mini-bog (compare adjacent graphic). It is not enough to fill simply the container brimful with soil, because water storage capacity is too low in that case and the bog will dry out from early summer on. In principle artificial bogs are – equally wether it concerns a mini-variant or a large landscape project – rather construct as a pond with a floating peat layer. Because peat sinks, as soon as it is saturated with water, the internal water reservoirs have to be marked out by a stable demarcation from the surrounding peat.

A bog pot (in this case an old laundry tub) in winter.

For construction of the internal water reservoirs normally plastic containers are used, in which all round numerous small holes were drilled, so that a water exchange between internal water reservoir and peat is ensured. Type of plastic containers is determined by the chosen external container. Internal water reservoirs should fill out the external container to the greatest extent and end circa 10 cm below of the top margin of the container. Convenient are for example flowerpots or plastic buckets, which are placed reversed (so with the opening downward) on the bottom of the container. Before numerous holes, circa as thick as a finger, are applied roundabout (also above at the bottom). Subsequently the container is filled halfway through with rainwater or distilled water and the spacings between the internal water reservoirs are tightly filled up with soil. For a raised bog suitable peat is enough alone, where necessary, some lime-free quartz sand can be mixed in, but what is definitely not necessary. Suited peat is exclusive unfertilized, low decomposed raised bog peat. Do not use another peat sort because you will otherwise obtain a disastrously poor result. Peat must, before it is brought in, be mingled well with water, because it floats otherwise. Therefore interstices are filled up to the top margin of the internal water reservoirs with soil and then some water is refilled, if necessary, so that the internal water reservoirs are completely filled with water. Finally the remaining 10 centimetres to the top margin of the container are also filled up with peat and some water is refilled once more.

Old pitchers of a Sarracenia flava in winter.

In plastic containers a drain hole should be drilled circa two centimetres below of the top margin, so that during heavy rainfalls water can drain off. Otherwise soil is filled up circa one to two centimetres above the top margin, so that excess water can simply drain off over the rim. The mini-bog is now so far as it can be shaped and planted. At first you can create different earth hummocks (elevations) and slots, then decorations like a root set in. Then you plant chosen species corresponding their light and moisture demands. Furthermore planting of the peat moss (Sphagnum spec.) is important for the enduring success. This is protected and must not be gathered from nature thus. It is in a few specialised nurseries and partially from other carnivorous plant enthusiasts obtainable. Search for it in the respective fora. Peat is all-year wet. In rainy conditions internal water reservoirs are refilled and during dry periods gradually depleted. By the peat cones water gets by capillary action of the peat to the soil surface. Cones act as a wick thereby. The peat moss maintains in the long term the milieu in your mini-bog. Special pumps secrete protons, wherewith they reduce pH-value and keep the bog „weeds-free“, because only adapted bog plants prosper under these extreme circumstances. To those count among many hardy carnivorous plants and some bog orchids a whole string of further interesting plants.

A special form – the low-moor bog:

Construction of a low-moor bog differs from a raised bog only in the uppermost layer. Instead of pure peat a mixture from peat and a sand-chippings-mixture is used (circa 60:40 mixed). For sand-chippings-mixture fine-grained lime chippings and calcareous sand are mixed circa in equal shares. A low-moor bog is especially because of the numerous non-carnivorous genera and species attractive. As carnivorous plants are hardy butterworts and Drosera linearis suited.

Annual care:

In a thick sphagnum layer this Sarracenia psittacina appears in January very vital.

A such designed mini-bog impresses with a markedly low need for care. In early spring old pitchers are pruned. In some circumstances, shortly later the bog must temporary be covered with a net or the like because nesting birds view the bog as construction yard and can partially pick it to pieces severely. Some months later you can possibly cater with the brush for a good seed setting. However, from early summer on it can in the case of hot weather for weeks infrequently happens that the internal water reservoirs must be refilled. That occurs maximal two to three times per annum and is the more improbable the better ratio of the volume of the internal water reservoir to the total volume is. In autumn you should direct your attention to the peat moss. During the cool-wet season this grows gorgeously and threatens sometimes delicate small plants to overgrow. Where necessary, this should be pruned. Generally butterworts and sundews should be planted only on nude peat because they partly have difficulties with the well-growing sphagnum in the long term. Finally, in late autumn frost-sensitive species should be covered with leaves and cut twigs. By the way: A raised bog is never fertilised!

Suitable carnivorous plants for an outdoor cultivation

Beside a number of North American pitcher plant-hybrids and some sundew-hybrids are the following pure species for a bog pot all-year suited. The list is not finally.

genus (botanical) species (botanical) English name annotation
Aldrovanda vesiculosa Waterwheel plant Plant for experts! Requires absolutely clean water. Addition of dried sedge and reed leaves advantageous.
Darlingtonia californica California pitcher plant Sensitive. Within peat moss, so that during summer not too hot. Winter protection necessary.
Dionaea muscipula Venus Flytrap Conditionally recommended. Only nominatform with winter protection well frost-hardy.
Drosera anglica English sundew Absolutely recommended.
Drosera binata Fork-leaved sundew Nominatform more or less frost-hardy, the more branched the variants, the more frost-sensitive.
Drosera filiformis Thread-leaved sundew Absolutely recommended.
Drosera intermedia Oblong-leaved sundew Absolutely recommended, requires a wet location.
Drosera linearis Slenderleaf sundew Basic soil!
Drosera rotundifolia Round-leaved sundew Absolutely recommended.
Pinguicula alpina Alpine butterwort Basic soil! In hot summers somewhat difficult.
Pinguicula grandiflora Large-flowered butterwort Basic soil!
Pinguicula vulgaris Common butterwort Neutral till basic soil! The easiest butterwort.
Sarracenia alata Pale pitcher plant Well frost-hardy.
Sarracenia flava Yellow pitcher plant Well frost-hardy.
Sarracenia leucophylla White pitcher plant Conditionally frost-hardy.
Sarracenia minor Hooded pitcher plant Well frost-hardy.
Sarracenia oreophila Green pitcher Plant Very difficult. Summer dormancy.
Sarracenia psittacina Parrot pitcher plant Only very conditionally frost-hardy.
Sarracenia purpurea Purple pitcher plant Very frost-hardy.
Sarracenia rubra Sweet pitcher plant Well frost-hardy.
Utricularia australis Southern bladderwort Absolutely recommended. Aquatic.
Utricularia bremii Small bladderwort More difficult. Aquatic.
Utricularia cornuta Horned bladderwort Absolutely recommended. Terrestrial.
Utricularia intermedia Flatleaf bladderwort More difficult. Aquatic.
Utricularia minor Lesser bladderwort More difficult. Aquatic.
Utricularia ochroleuca Yellowishwhite bladderwort More difficult. Aquatic.
Utricularia purpurea Eastern purple bladderwort Aquatic. Low water level. Add sand to the soil. Frost-hardy are only clones from Canada or the Northern USA.
Utricularia stygia Arctic bladderwort Absolutely recommended. Aquatic.
Utricularia vulgaris Common bladderwort Absolutely recommended. Aquatic.

Suitable bog orchids for an outdoor cultivation

genus (botanical) species (botanical) English name annotation
Arethusa bulbosa Dragon’s Mouth Orchid Very attractive. From North America. Within sphagnum at slots in raised bogs. Very sensitive. Cut sphagnum in autumn!
Calopogon tuberosus Grass-pink Very attractive. From North America. Wet site within raised bogs.
Cypripedium acaule Pink Lady-slippers From North America. Half-shaded, rather dry site within in raised bogs.
Cypripedium reginae Showy Lady’s-slipper From North America. Easy and groß werdend. Calcareous fens.
Dactylorhiza incarnata Early Marsh Orchid Native species. Low-moor bog.
Dactylorhiza maculata Heath Spotted Orchid Native species. Calcareous fens, low-moor bog.
Dactylorhiza majalis Broad-leaved Marsh Orchid Native species. Low-moor bog.
Dactylorhiza sphagnicola Spotted Orchid Native species, rare. Raised bog.
Epipactis gigantea Stream Orchid From North America. Easy, breeds by stolons. Low-moor bog.
Epipactis palustris Marsh Helleborine Native species. White, dark red blossoms. Low-moor bog.
Gymnadenia conopsea ssp. densiflora Marsh Fragrant Orchid Violet-pink blossoms. Large. Low-moor bog.
Gymnadenia odoratissima Short-spurred Fragrant Orchid Pink, scented blossoms. Distinct smaller. Low-moor bog.
Hammarbya paludosa Bog Orchid Very delicate, green species. Native, threatened with extinction. Raised bog.
Herminium monorchis Musk Orchid Delicate, green species. Native and rare. Low-moor bog.
Liparis  loeselii Fen Orchid Native, rare species. Low-moor bog.
Orchis militaris Military Orchid Native, endangered species. Low-moor bog.
Orchis palustris Lax-flowered Marsh Orchid Native, threatened with extinction species. Low-moor bog.
Platanthera bifolia Lesser Butterfly-orchid White blossoms. Low-moor bog.
Platanthera blephariglottis White Fringed-orchid White blossoms. From North America. Raised bog.
Platanthera ciliaris Yellow Fringed-orchid Filigree, orange blossoms. From North America. Raised bog.
Platanthera clavellata Small Green Wood Orchid Small, greenish blossoms. From North America. Rather half-shaded. Calcareous fens.
Platanthera lacera Ragged Fringed-orchid Filigree, white blossoms. From North America. Raised bog und calcareous fens.
Platanthera psycodes Small Purple Fringed-orchid Purple blossoms. From North America. Calcareous fens.
Pogonia ophioglossoides Snakemouth Orchid Very attractive species with large, pink blossoms. Breeds easily vegetative. Raised bog.
Spiranthes aestivalis Summer Lady’s-tresses Native species. For low-moor bogs.
Spiranthes ochroleuca Yellow Nodding Lady’s-tresses From the East Coast. For low-moor bogs and raised bogs.
Spiranthes sinensis Chinese Lady’s-tresses Pink blossoms! from Asien. For low-moor bogs and raised bogs, rather dry.

Other suitable bog plants for an outdoor cultivation

genus (botanical) species (botanical) English name annotation
Aster nemoralis Bog Aster Pale purple blossoms, 20 cm high. From North America. For the raised bog bed.
Calla palustris Bog Arum White blossoms, red berries. For the low-moor bog.
Calluna vulgaris Common Heather Perennial bush, up to 50 cm high. For dry sites in the raised bog bed.
Erica tetralix Cross-leaved Heath Up to 40 cm high. Rather moist sites in the raised bog bed.
Eriophorum angustifolium Common Cottongrass Decorative, white seed heads. Cave: Has a disposition to proliferating! For wet sites in the low-moor bog bed.
Eriophorum latifolium Broad-leaved Cottongrass Also white seed heads. Wet sites in the low-moor bog.
Eriophorum russelianum Orange-coloured Cottongrass From North America to Asia. Attractive orange seed heads. Delicate growth. Wet sites in the raised bog.
Eriophorum vaginatum Hare’s-tail Cottongrass From North America. Cupreous seed heads. For the raised bog.
Fritillaria meleagris Checkered Lily Blossoms patterned. Often dark basic colour. Low-moor bog bed.
Gentiana pneumonanthe Marsh Gentian Blue blossoms, wet site in the low-moor bog bed.
Gladiolus palustris Marsh Gladiolus Attractive. Crimson blossoms. Low-moor bog.
Iris sibirica Siberian Iris Dark blue blossoms, slender leaves. Low-moor bog.
Lobelia cardinalis Cardinal Flower From Canada. Scarlet blossoms in autumn. Winter-protection! Rather calcereous fen, wet location.
Menyanthes trifoliata Bogbean Fringy, white blossoms. Fast-growing. Wet site in the low-moor bog bed.
Molinea caerulea Purple Moor-grass Typical tuft-building grass species of bogs.
Parnassia palustris Marsh Grass-of-Parwetus White blossoms in July. Wet site in the low-moor bog.
Primula farinosa Bird’s-eye Primrose Pink blossoms. Often accompanied by butterworts within low-moor bogs.
Trollius europaeus Globe-flower Flower of the year 1995. Bright yellow, spherical blossoms. Rather nutrient-rich site within the low-moor bog bed.
Vaccinium oxycoccos Small Cranberry Creeping, perennial bush with edible fruits. Wet site within the raised bog bed.
Vaccinium vitis-idaea Lingonberry Perennial bush. Barely 20 cm high. Raised bog.