Marginal aquatics & bog plants (Pond Plant Biotypes 4 & 5)

As short as the previous chapter was this section promises to be long and hopefully not too dreary.

Bog plants root strongly into the mud and consume debris, fish mulm and rotting leaves as they go. Some confusion exists trying to distinguish between bog plants and bog marginals, but generally the former refers to plants of somewhat stronger constitution growing in from 5cm (2 inches) of water to fairly deep-water aquatics.

Biotypes 4 and 5 fit in here and will be catalogued together as one group. Marginals are plants demanding bog conditions but which generally inhabit the 'margin' or edge of the water garden. They are thus smaller, often scrambling plants for clothing the side of your pond. The division is artificial but we have kept them as a seperate group.

All bog plants need a fairly rich soil with added compost, manure and fertilizer. Strike a balance, however, because most are very vigorous growers and given the least encouragement will take full advantage. Sometimes a bit of healthy starvation helps to limit their unrestrained growth while obviously assisting in keeping the water clearer.

This listing is extensive and will include many that may not be easily available. They are, however, growing happily somewhere in the local garden scene. If you pester your favourite nurseryman often enough he will finally succumb and make suitable enquiries. Alternatively, gardeners are friendly folk and love to share their collections.

Section A Tallish bog aquatics

1. Acorus calamus. 60cm - This is the 'Sweet Flag' of ancient history, is effectively a pond side rush with deliciously aromatic leaves. In external appearance, not unlike an Iris, it lacks an obvious flower but compensates by being hardy, easily grown and effective, according to herbalists of old, in repelling cobras!

2. Acorus gramineus 30cm - Exceedingly common in most nurseries and sold as a ground cover grass. The form 'Variegata' is best and grows deep in up to 20cm of water or spreads out, over and up the pond margin.

3. Alisma plantago Aquatica 60cm - Water plantain. The broad leaves of this plant are often useful in the water garden picture, but it can be rather weedy. It throws up a delicate branched pinnacle of tiny flowers which are very charming. Old flowers heads should be cut away before they scatter their seeds widely and germinate in every nook and cranny.

4. Berula 40cm - This is a well-known ubiquitous plant which finds it's way into every pond. Nomenclature is by no means certain, but the University identified it as Berula. The leaf is course fern like and the flower an umbel resembles 'Queen Anne's lace' or not unlike Angelica of a more subdued sort. Effective in deep planters for control and once again remove the flower head as it is apt to become a nuisance.

5. Botumus umbrellatus 90cm -'Flowering Rush'. Rare in this country but very common around every pond in Europe. Botumus demands a free root run in up to 10cm of water and needs constant re-potting to keep it flowering. The rewards are worthwhile as the showy umbels of pinkey flowers show off above the thin sword-shaped leaves. In Autumn the leaves turn bronze while the seed heads remain showy until cut.

6. Calocasia esculenta 1m -'Elephants Ear'. This is a grey green form with the point of the immense leaf facing earthward. It thrives in very wet bog and can increase alarmingly. Not reliably hardy but it does add a 'tropical appearance' to the water feature.

7. Cyperus Sedge The very large Sedge family has many and various manifestations. All are, of course, grass-like and have brown to yellow inflorescences of not great beauty except for dry flower arrangement. The following are the most common:

8. C. Alternifolius -'Umbrella palm' Very well known habitu of the local water garden scene. Tall, to 1,5m with the tufted leaves growing out flat or drooping, if grown in shade. Best confined in a pot and very useful in indoor ponds. There appear to be several forms or cultivars such as 'Gracilis' which is slenderer and grows to 45cm. 'Nanus' which is smaller still and 'Variegatus' which although listed in catalogues, I have never seen.

9. C. Diffusus 25cm - and it's variety 'Variegata' are low spreading plants used externally as ground cover for outdoor and indoor features. The variegation is seldom stable and needs constant care, removing any green shoots which appear.

10. C. Haspan 60cm - resembling a miniature Papyrus, this plant is a useful addition to the bog garden. It grows in mud or shallow water and can reproduce by the contact of the flower heads with the surface of the water. As early as 1936 this was named 'Haspan' but Dr Forbes indicates in her section of 'Flora of the Witwatersrand' that the name is in fact 'Halpan'.

11. C. Papyrus 2m - and more if the soil is wet enough. It can 'run amok' if the conditions are wet and fertile and are useful, according to tradition, for warding off unwelcome crocodiles. As they apparently abhor Papyrus, always carry one when you visit your neighbouring water garden! Papyrus is a noble plant and indispensable for large scale planting. There is a deal more Cyperus species growing freely and wild throughout the country. Many are rather weedy and some extremely troublesome (C. rotundus etc) such as 'Uintjie' or Watergrass, so be careful about introducing any unknown to your garden.

12. Echinodorus 50cm -'Amazon Sword'. A plant used extensively in aquaria, but which does equally well in a protected outdoor pond. The leaves resemble Alisma but are distinguished by 3 prominent veins running the length of the leaf. The flowers are button sized, white and if allowed to rest on the water, will form new little Echinodorus'. It grows in shallow or deep water, but is not reliably hardy.

13. Gunnera spp there are a number of species worth including in the bog, one of which is truly magnificent. The indigenous kinds can be ferocious in a small area but are well worth growing if controlled. Spring sees them unfold dark green cabbagey leaves - any wet situation in sun or shade will do. They can be collected from alongside any local stream. Gunnera manicata is another story! Huge umbrella-sized leaves of rough texture stand out bold and sculptural. They need space, shade and deep rich, wet soil to do their best.

14. Houttynia cordata 50cm-a very useful new addition to the list of bog plants available in SA despite it's clumsy name it is a super creeping bushy plant with blue-green heart-shaped leaves which turn rusty in the autumn. Its flowers are an interesting white blob with cone-like centre and it thrives in shallow water to very wet mud. In designing plant associations, the leaf of Houttuynia is a useful change from the ferns or spikey leaves of the iris tribe.

15. Iris spp the bog iris is a large and varied group inevitably leading to confusion in naming. Mainly known as 'Louisiana' there are in fact many others which do not hail from North America or the Bayou Swamps. The majority are hybrids of these American species and can be acquired in named varieties as 'Zulu' or 'royal salute' from specialist growers.

16. I. kaempferi 90cm-stately aristocratic plants known as the 'clematis flowered Japanese iris thinnish spear shaped leaves appear in spring, Distinguished by a prominent mid-rib not unlike schizostylus. The blooms are spectacular and have been bred and in bred to offer a great variety of colour. They form large clumps and thrive in very wet soil during summer. Drier conditions suit them best in their dormant phase.

17. I. laevigata 45cm - smaller than the preceding species, but with broader, bolder leaves and bright, simple typically iris flowers. The varieties usually available are the dark blue and white called 'snowdrift'. Laevigata grows in the water and forms impressive clumps in time. Somewhat more deciduous than the Louisiana'.

18. I. louisiana 60cm - this covers a multitude of various plant mostly hybrids of L. fulva, caroliniana and versicolor. The hybrids cover almost the entire colour range and all can be grown in bog or shallow water. They are almost evergreen but need to be cleaned up in early spring.

19. I. Pseudocorus 1,2m - at its best this is a stately, valuable plant in the pond. It grows taller than most, in shallow water or wet mud and offers bright yellow flowers around October. The leaf ribbed unlike Laevigata from which it can be distinguished. Called 'yellow flag in Europe.

20. I. Versicolour almost a purple form of Pseudocorus, this can be cultivated in a similar way at the edge of the pond or even plunged in pots. This often offered as seed by some mail order catalogues.

21. Lobelia cardinalis 60cm 'Queen Victoria' - few gardeners realize that lobelia will grow knee deep in water and be as happy as a heron. The dark red leaves and flowers are useful in the garden design, but keep them away from bright yellows such as Caltha. They flower in late summer and can spread seed about in an alarming manner.

22. Ligularia spp these imposing plants are seldom offered by nurseries, but should become available as time goes on. The leaves are large and the flowers daisies. Very wet soil to bog.

23. Pontedaria cordata 20cm 'pickerel'-one of the finest aquatics available. This is the rarer dwarf form, while the commonly grown plant is P. Cordata lancifolia. Bold shiny spear shaped leaves set off spike of the brightest blue flowers. It appears that this plant has been prohibited by the 'powers that be' on the assumption that they are invasive as the water hyacinth. This is patently absurd because the dwarfed form is in fact difficult to grow, while 'Lancifolia' is limited by the highveld frost, depth of water and by running water. Eichornia or 'water hyacinth' itself is a fiendish plant and is required to be rigorously controlled. Pontedaria makes a stunning specimen plant in a large pot plunged deep in the water. Groom the plant occasionally removing dead leaves and flower heads.

24. Prionium palmita 1,5 m 'Palmiet' - a most vicious plant with narrow leaves resembling a gigantic 'pampas grass' without the plumes. It forms an impenetrable clump and can be used to advantage in repelling terrorists. Not the plant for a small suburban water garden, but used effectively at Kirstenboch and Sun City on the grand scale.

25. Sagittaria 45 cm - a fascinating genus which offers 3 differing leaf types submerged, floating and emergent. The classical Sagittaria saggitifolia of Europe has an arrow-shaped leaf with long basal lobes, an exciting leaf formation. It is not freely available in SA but as it grows very easily it should become easier to get plants. Flowers are white buttons set on erect spikes. More common is S. platyphyllos which is often sold as an oxygenator because of its strap-shaped sub-aquatic leaves and considerable oxygenating powers. Above the water they assume a spear shape not unlike alisma and flower freely though somewhat unexcitingly. The creeping rootstock needs to be controlled. An excellent plant for cleansing a pond and assisting in a balanced ecology.

26. Saururus cernuus 50cm - 'Lizard Tail' - which refers to the droopy racemes of tiny flowers produced in late spring. The leaves are 'heart shaped' and come as a refreshing change of leaf form. The plant can accept some shade but seems prone to attack by red spider mite. Uncommon but becoming increasingly available.

27. Thalia dealbata 1,75m - aristocrats of the water garden thriving in wet mud or shallow water. Amazingly they claim allegiance to the Maranta family and produce large Canna-like leaves and stately arching spikes of purplish flowers. Hardy to the worst of our winters, the Thalias need a rich free root run and may sulk if confined in a too small container.

28. Typha angustifloria 2m 'Bulrush' - every reference book tell us that this is not a 'Bulrush' but it has become so, by popular usage and there it stays! Actually the name 'Reed Mace' is nicer and far more descriptive of the furry brown inflorescence which thrusts above thin reedy leaves. This plant can be very invasive and should be used with caution in a small pond - or else confine it strictly in an unbreakable receptacle.

29. Wachendorfia thyrsiflorus 1.5m - indigenous bog perennial growing up erect with bright yellow poke-like flowers. The leaves are dark green crinkled swords not unlike an Iris, but distinct. The indispensable bog plant grows in very wet mud and associates happily with Arums and Cyperaceae in vast tracts on the P.E. side of the Garden Route.

30. Zantedeschia needing little introduction the 'Arum' is a thoroughgoing plant without peer in the water garden. The plant is almost evergreen, flowers with charming regularity and can be cultivated in bog to fairly deep water. It seems almost axiomatic that the best plants have the most grotesque names, but call it Arum, or 'Calla' it should nevertheless be in every pond.

31. Z.. aethiopica 60cm - or more growing in compost rich soil, in sun or shade, the Arum is most rewarding in leaf or flower. A form called 'Little Gem' has been named and described as 'dwarfed' than the species, but seems scarce in the trade. Flower arrangers value the green arum which appears to be identical to the above species but with larger tapering spathe and green colouring. The spotted leaved 'Albomaculata' is stunning in the shade and appears to cope with less water than the usual white. Other colours such as yellow, Helen O'Connor etc are not bog plants.

Section B Bog marginals and edging plants (Biotype 6)

Type 6 in our Biotype listing. These plants are basically the same as the proceeding list but smaller and more refined. Most are scrambling blank clothiers which have a very primitive understanding of their own 'group area' and tend to poach and intermingle freely. In point of fact this creates a very natural picture although occasional weeding can sort out any over enthusiastic performer. An interesting mix is Bacopa interplanted with Eriophorum and Mentha. Thrusting through this carpet, plant Myosotis (Forget-Me-Not) and Schizostylus or grassy ground cover such as Mondo Grass.

1. Bacopa monieri 'Babies Tears' - Carpeting ground cover which grows in, under and out of water - hence ideal for the muddy edge. The leaves are tiny, evergreen and sufficiently hardy to grow out quickly in August. It grows in shade or sun provided the substrate is very wet and flowers ceaselessly. Flowers are tiny two tone pyramids produced with joy abandon covering the banks like the old fashioned 'Daisy Lawn'.

2. Calla palustris 20cm - Very tiny arum-like flowers and leaves borne freely on the creeping rootstock. Rarely available in nurseries. Not to be confused with 'Arum' indigenous to SA, a plant often called 'Calla' in Europe and USA.

3. Caltha palustris 20cm - 'Marsh Marigold'. This is one of the best small bog plants around. It forms a low bushy plant in 5cm of water or very wet mud. In Spring (late August) it fluffs out masses of round heart-shaped leaves and then proceeds to cover itself with very yellow buttercup flowers en masse. Caltha is very hardy, prefers half shade and is a star for every small pond.

4. Caltha polypetala 25cm - A new arrival in the nursery and if anything, better than the preceding. The lush verdant leaves are almost evergreen and certainly very showy in the early Spring when they appear to be almost edible. In the East the fresh leaves are in fact used as salad. From the crown of the main bunch of leaves the plant pushes out a fleshy succulent runner which roots strongly into the mud, while at the same time bearing a cluster of 3cm wide, bright yellow 'buttercups' Altogether a magnificent accent plant for stream side to the shallow running water of the 'rill'.

5. Cotula corinopifolia 'Water Buttons'. Yellow again - the main spring colour can be very yellow if not carefully planned! This is a free running ground cover which revels in wet situations in sun or half shade. The golden yellow 'buttons' are produced freely sprinkled over rust and green, mildly aromatic foliage. Cotula propagates itself with unabashed fervour and should be carefully controlled. It is nevertheless a useful clothier of pond margins and particularly in more difficult or less choice situations.

6. Crinum campanulatum 'Bog crinum' - 30-40cm. A choice and beautiful plant which never ceases to cause comment. Featuring the usual pink lily - like crinum flowers and having added distinction of being indigenous, C. campanulatum is also an elegant plant for shallow water. One of our esteemed local authoresses stresses the plants need a 'rest' period in winter, i.e. to allow it to dry out. This is to stimulate a Mediterranean climate in deference to its Cape origins. Mostly water gardens allow it to remain in 2 or 3 inches of water and still it seems to flower successfully at odd intervals. The secret is probably feeding.

7. Eriophorum augustifolium 'Cotton grass' - Grassy little plant with thin unattractive foliage, but producing masses of 'cotton wool blobs' of fluffy flowers in profusion. It only grows 15cm and revels in very wet mud. Very useful for a miniature pond or small stream.

8. Ludwigia A rather vigorous plant which cannot be recommended for small garden application. It has been used as an aquarium plant but once let loose in a benign environment, it often simply takes over. Good ground cover for larger areas.

9. Lobelia cardinalis 40cm - A red leafed perennial aquatic which is often grown in the herbaceous border. Included here because it adds an unusual colour, with it's dark red flowers, to the pond scene. Lobelia can actually stand in shallow water, but be chary of its seeding propensities! See lobelia 'Queen Victoria'.

10. Lysimachia nummularia 'Creeping Jenny' - A great companion to 'Lucky-lurk-in-a-ditch' (Glecoma). The fresh green, and sometimes yellow, leaves carpet and clothe banks in sun or shade. Indispensable for the streamlet and pond margin. Called money' in Northern England. A rooted sprig is passed down from mother to daughter through generations and planted for prosperity in every garden!

11. Mentha pulegium 'Penny royal' - There is a genuine aquatic Mentha called M. Palustris, but as yet unavailable in SA. Penny Royal is the well-known carpeter with a pungent aromatic leaf. It can grow under water if required to, but prefers a half shaded wet situation where it will clothe the banks. The dense foliage includes many weed plants from germinating.

12. Myosotis 'Forget-me-Not' - Blue of course! Scatter a packet of seeds in Spring and weed out the unwanted when they appear. It will seed itself thereafter and be a constant joy in every rocky cranny.

13. Ophiopogon japonica 'Mondo grass' - This little dark green grassy (actually Liliacea) ground cover has become very common of late, sometimes overmuch! Where it can't really cope on hot dry island beds it fades to a scorched yellow and makes everyone feel miserable. In shade and wet it's very buoyant, dark green and lush growing. Mondo can accept shallow water, wet mud and shade or half shade where it produces iridescent turquoise berries snuggled down in the foliage.

14. Primula spp Bog Primulas are one of the most common perennials in every bog garden world wide except SA. Seldom if ever offered in Nurseries, you may have to grow these yourself from seed. Try a friend who gets RHS seed from Wisley or one of the local seed merchants.

15. Schizostylus coccinea 30cm 'River Lily' or 'Red Flag' - Indigenous bulb and an outstanding bog plant. The starry flowers open successively over many days adding a bright splash of colour to the pond margin. The blooms are bright red, pink or pale pink. River Lilies grow almost anywhere and die down only briefly in July / Aug provided the soil is moist or even very wet. Thick clumps containing many bulbs result once the plants are established.

Section C Grasses, sedges and rushes for bog and margin

These have been kept as a separate group simply to assist in planning the overall pond planting. Many bulbs and aquatics have spiky, sword-like leaves and beautiful flowers. Grasses are a distinct group and often form the largest colonies in natural ponds and lakes. They all need control as they take full advantage of garden conditions and care. The Cyperaceae have recently been revised or at least juggled by botanists but we here confine ourselves to horticultural distinguished varieties. Cyperus proper has already been included as being the least grassy looking.

What follows is more in the nature of a list to indicate which grasses can grow in wet soil or pond margin. Many are equally at home in the perennial border and form an excellent screen and background to the pond.

1. Carex Sedge 20cm. Varieties are 'Bowles Gold' and C. morrowi'. Plant in colonies to form grassy mounds.

2. Elegia capensis 1m or more 'Cape Rush' of the Restio persuasion. This is an interesting, indigenous clump forming plant, sending masses of plumed or cats tail-like stalks and leaves.

3. Glyceria 'Manna Grass'. A low clumpish grass with striped, variegated leaves. Not common but sometimes available.

4. Juncus 'Rush' there are a number of indigenous species growing extensively in very wet places. One such is commonly called 'creeping rush' (oxymoron?) and has an indispensable place around every pond. The leaves are rust coloured in winter.

5. Miscantes spp Showy variegated grass up to 2m of exuberant, fountains of growth. Border or backing plant.

6. Phragmitis spp The indigenous 'reed' which covers acres of wet mine land South and South East of Johannesburg. Not a garden plant.

7. Scirpus properly the 'Bulrush' but more commonly known or distinguished by it's variety 'Zebra Rush'. S. lacustris is the most common 1,5m rush growing all over the world, while S. Zebrina is the well-known horizontal striped plant mentioned above.

There are multitudinous species, often extremely alike and all somewhat invasive. Some of the tiny annual species can be planted in miniature water schemes.

For the larger gardens some of the noble grasses blend in beautifully with the pond scene. They need to be given either space to achieve their full potential, or else confine in half drums sunk into the ground.

Of these the best bamboo is Phyllostachys aurea commonly called 'Golden Goddess' in S.A. nurseries. P. nigra is the black-stemmed bamboo and can be difficult to locate. Larger bamboo are generally too huge for suburban gardens unless you have a yen to see 'Buddhas belly' towering above you.

Arundo donax 'variegata' can be planted where space is no object. Bright creamy variegation can be stimulated by cutting back every winter. This is a true 'reed'.

The other wild reed or 'Biesie' is Phragmitis australis which has been mentioned already and is not a garden plant. Vast tracts of mining land to the South of Johannesburg are given over to this reed.