Garden Pond Plants

This group includes many promising species and varieties. The most important characteristic to consider with the selection of pond plants is size: many grow too large for use in aquarium enclosures. One should also be aware of dormancy requirements. Most of the pond plants described by vendors as “hardy” demand extended cold winter dormancy periods, so they are less suitable for growing in permanent indoor displays. Those described as “tropical” are usually better choices. Some tropical to sub-tropical pond varieties, such as many of the flowering bulbs and dwarf taros, do require a dry season winter dormancy, but this can be accommodated by removing their planters to a cooler, dryer location (such as a basement floor) for a few months.

Most pond plants will grow best with good air circulation and bright illumination. They look and prosper best in open-topped displays.

Mexican Petunias (Ruellia brittoniana)

These very attractive plants are offered in two distinct growth forms. The erect “Blue Bells” types grow to 2-4′ tall and are similar to their wild progenitors. The semi-compact ‘Katie’ and similar cultivars grow as short bushes to about 12″ tall. Flowers range in color from pink to light blue to purple.

Mexican petunias are extremely tough plants and are popular landscaping elements, both for ponds and moist-soil areas. They grow vigorously in ripariums and will flower if provided with ample light and fertilization. The taller bluebells Ruellia varieties are easily coaxed–with pruning and/or tying to other objects, in a manner similar to bonsai training–to reach forward into the composition midground. Mexican petunias are susceptible to spider mites. Treat promptly with an isoproyl alcohol bath in case of infestation.

Ruellia brittoniana are available from many garden centers, where they are sold as patio plants and pond specimens, and from Internet vendors.

Rain Lilies (Zephyrathes sp.)

There are many commercially-available species and cultivars in Genus Zephyranthes. While they are not especially appealing as foliage plants–most have sparse, onion-like leaves–their blooms are wonderful. Many of the garden varieties that grow well in ponds are pink or white in color. Others may be less hardy in saturated soils.

These plants are recognized with the common name “rain lily” because they emerge from their dry season dormancies with many blooms after the first showers of the sub-tropical rainy season. They are most likely to flower if removed from the riparium for a few months during the winter to a cool, dry location. After placing them back in the warm riparium water they will often respond with many new blossoms. Planting in riparium hanging planters facilitates this transfer. Give rain lilies plenty of light and regular fertilizations while growing so that they can build the energy reserves required for flowering.

Most of my experiences growing rain lilies in ripariums have been with Z. candida and Z. macrosiphon. These and other varieties are offered by a number of Internet vendors.

Sweetflag (Acorus gramineus)

Genus Acorus contains a few species of grass-like wetland plants. Most commercially-available sweetflags are cultivar varieties of A. gramineus, which is native to East Asia. These plants have a range of sizes and leaf colorations. Dwarf varieties (e.g., ‘Minimus Aureus’) are too small to be of much use in ripariums. Look for the selections that grow from 10″ to 15″ tall. Two varieties with green + yellow pin-striped leaves, ‘Oborozuki’ and ‘Ogon’, have grown into beautiful specimens in my ripariums.

You could almost argue that these plants were made for planting in ripariums. The long-lasting foliage has a neat, bright appearance and its gently arching form is useful for re-creating the grassy shorelines found along the edges of rivers and lakes. Best of all, many of the leaves grow upward from the creeping rhizome at a 45° angle, so they ascend perfectly from the riparium background into the composition midground. This supports the effect of visual depth.

Sweetflags are more difficult to come by than some other pond plants, but you should be able to find some of the useful A. gramineus varieties if you research among several online vendors.

Houseplants/Tropicals

This is a very large group containing many plants that are clearly unsuitable for culture in wet environments. However, there are quite a few varieties and species kept as houseplants or tropical greenhouse specimens that adapt well to riparium environments. The best candidates among this group of plants are those that grow in wetland or riparian habitats in nature. A few such plants are common and readily available. It might be possible to assemble many of the plants for a riparium display by shopping the garden section at a big box home improvement store or comparable retail outlet.

Since many are selected for their resilience and adaptation to indoor conditions, houseplants might be used to assemble low-light, low-maintenance riparium displays. These plants are usually sold in well-draining soilless potting mediums, even if they might also be able to grow in saturated soil. Such plants will benefit from an adaptation period–the water level in their planters slowly increased–before having their roots fully submersed.

Peace Lily (Spathiphyllum)

Most of the cultivated varieties of Spathiphyllum originate from species that grow in swampy forests and similar habitats in the Neotropics (Central America and South America). Despite the ready availability of peace lilies as potted plants, there seems to be little readily-available information on their horticulture or ecology in nature.

I have tried a few different peace lilies. One cultivar with large, shiny leaves and showy flowers refused to develop roots in wet media, but the others all established quickly in riparium planters and grew well. The varieties with shorter, more slender leaves are easier to use than larger plants, which can fill too much space. Peace lilies grow well in the shade. In fact, bright light can cause chlorosis and poor leaf development. A single potted Spathiphyllum can easily provide all of the divisions that you need to develop the background of a riparium composition. Most peace lilies have dark green foliage, so they provide contrast for light-colored or variegated plants.

Surprisingly, there seem to be few online offerings of peace lilies. This might be due to their ubiquitous availability at every kind of store that sells decorative plants.

Taros (Alocasia sp., Colocasia sp. and Xanthosoma sp.)

There are many species and varieties in the genera Alocasia and Colocasia, which originate from tropical areas in the Old World and the New World. The natural habitats of many species include swampy forests or the banks of rivers. A few are widely grown for their starchy tubers, which can be cooked like potatoes, while others are popular as decorative plants. Taros have large heart-shaped leaves that can bear various rich colors and bold patterns. Some have very shiny foliage, while others have beautiful satiny sheens. Most grow too large for riparium culture, but among those grown in garden ponds or as houseplants are a few shorter-statured selections.

An especially successful discovery that I have made is Colocasia fallax. This plant grows to only about 14″ tall and its growth habit is perfect for keeping in ripariums. A plant rooted in a hanging planter on the rear pane of glass will develop arching leaf stems with tear-shaped leaves that hang vertically out in the composition mid-ground. Each satiny green leaf has an area of lighter coloration near its center. This plant makes an excellent focal piece if planted among finer-leaved foliage. It prefers to have its crown slightly above the water level. C. fallax and other dwarf taros might require winter dormancies. If they stop growing or if leaves start to deteriorate--mine did this after flowering--remove their planters to a shallow dish of water and place in a cool, shaded location . After a resting period of several months they will respond with vigorous growth when replaced to the warm riparium environment.

There are undoubtedly several more dwarf taros in addition to Colocasia fallax that will perform well in ripariums. Look for small varieties that are described as growing in wet soil.

Purple Waffle Plant, Dragon's Tongue (Hemigraphis sp.)

Hemigraphis are readily available and likely to appear at any store that sells houseplants. The species H. exotica and H. repanda are the most common. Online sources describe them as originating from Southeast Asia. Many apparently occur in wetland habitats in nature. Most of the commercially available Hemigraphis have deep green leaves with purple or dark magenta undersides.

As is true for many stem plants, the maintenance of Hemigraphis can be tricky in the riparium: they tend to fall over and can assume a messy appearance. It is best to use them as accents among tidier rosette plants. They are good companions for Spathiphyllum, Anubias and other low-light specimens. Pair with Cryptocoryne to create a representative Asian biotope.

Hemigraphis are slow-growing stem plants with apparently modest nutrient requirements. They grow well if planted on a Nano Trellis Raft with their roots suspended directly in the aquarium water, especially in low to moderate lighting. You can also root Hemigraphis in Hanging Planters. By pruning their tops as they grow in height you can encourage them to grow as small bushes.

Aquarium Plants

This category includes many intriguing possibilities. Any planted aquarium enthusiast likely has on-hand several aquatic plants that will grow well as emergents in a riparium. Many plant species that can grow either in the air or in the water develop distinct leaf forms in each environment. Such plants equire some special care and adaptation periods to transfer from immersed to emersed growth.

Some of the plants that are used in planted aquaria require high humidity for healthy emersed growth. These should be grown in an aquarium with a glass canopy that covers most of the top. Others, such as swordplants (Echinodorus sp.), prefer more air circulation and grow well in open-topped displays.

Anubias (Anubias sp.)

All Anubias species can be grown as emergent plants. A few, such as A. gigantea actually have poor growth if kept in a permanently immersed state and are better candidates for emmersed culture. The wide range of sizes of Anubias species offers many possibilites their use in riparium compositions. Short-statured, low-growing kinds (e.g. A. barteri ‘Nana’) serve well in the display midground, while tall, erect species (e.g. A. afzelii) function well in the background or as centerpiece plants.

There are a number of strategies and techniques for riparium culture of Anubias. These plants are among the aquatic flora that can transfer directly from immersed to emmersed growth and vice versa, an adaptation to their natural riverbank habitats in West Africa, which are subject to seasonal flooding. Thus, you can take an Anubias plant directly from underwater culture and plant it in a hanging planter or on a trellis raft. However, such a plant will require very high humidity to avoid leaf desication and damage. Be sure to cover the riparium display to maintain high humidity, especially during the period right after planting as emergents. An iarstone situated beneath the Anubias will splash dorplets of water onto the leaves and further raise humidity in the plant's vicinity.

It is widely recognized that Anubias plants prefer to grow upon their habitat substrates, such as rocks and sunken logs. Planting them with their thick rhizomes buried in the substrate usually leads to rot and death of the plant. The Epi-Trellis raft was designed especially for growing Anubias and other plants with similar growth habits, such as Microsorum and Bolbitis ferns. After being planted on top of the raft–held in place with small plastic cable ties–the Anubias rhizome develops new roots which grow down through the numerous holes in the raft. In time the plant will branch and cover the raft from view. You can hold the raft in place against the aquarium glass or a hanging planter with hook & loop fasteners. Plant taller Anubias in Hanging Planters. Some large Anubias, such as A. hastifolia, can grow well in a fine-grained substrate, such as Riparium Planter Gravel, while others, such as A. congensis, apparently require a more open medium. Clay pebble substrate might be a good choice for this latter group and will allow free water circulation around the roots. As with other methods, if you plant Anubias in a Hanging Planter make sure that the rhizome remains on top of the substrate.

Crypts (Cryptocoryne sp.)

This is a large group containing many species with potential for riparium culture. The Cryptocoryne are beloved aquarium plants: as a group they are perhaps the most popular of all. Their species diversity, wide range of forms and the general hardiness of many crypt species contribute to their frequent application in underwater displays. The same traits have led to the growth of an intriguing pastime among some aquarium hobbyists and tropical plant fanciers, the tending of Cryptocoryne in emersed culture. In their native habitats, most crypts pass at least part of the year growing above water. It is during this period that most species bloom. Indeed, flower development is the ultimate goal of hobbyists who keep emersed Cryptocoryne. Crypt flowers have strange, exotic looks and they are the most reliable feature to use for species determination: some crypts can only be distinguished with examination of flower characters.

Among the Cryptocoryne the most useful species for ripariums are those that grow relatively tall. Some crypts, such as C.parva and C. petchii, only grow to two or three inches in height. Such plants would serve poorly as background elements if planted in hanging planters and would be lost in the foliage of larger plants. However, they would be good choices as underwater foreground plants, especially if used in combination with larger emersed form Cryptocoryne. The following list suggests some of the best crypts to plant in hanging planters for use as background foliage in a riparium composition:

• Cryptocoryne ciliata
• C. cordata (some varieties)
• C. crispatula var. balansae
• Cryptocoryne lutea
• Cryptocoryne wendtii

In addition to their robust growth these species and varieties are all quite hardy in emersed culture. The last species in this list, C. wendtii, is perhaps the hardiest of all and includes a number of varieties with distinctive leaf colors and patterns. As they grow in stature crypts tend to arch and lean into the center of the aquarium enclosure, an effect that is useful for creating visual depth. Combine them with short-statured stem plants grown on Trellis Rafts, such as Bacopa or Rotala, and floating plants to develop a richly textured riparium composition.

A great deal has been written about growing Cryptocoryne culture, both for their use as aquarium plants and in theemersed condition. For riparium culture a primary concern is maintenance of proper humidity levels. Most crypts demand very high humidity, so the aquarium enclosure should remain completely covered, or nearly so. You can also use an airstone positioned directly beneath your emergent crypts to splash water up onto their leaves and raise humidity. On the other hand, a few crypts, such as C. spirales and C. cordata, might exhibit more attractive growth with somewhat drier air and more air circulation. Water chemistry, temperature and substrate composition are additional important variables to consider in emersed Cryptocoryne culture. There are many online resources with good information about growing crypts.

The most common Cryptocroyne species and varieities, which happen to also be some of the least fussy and hardiest, should be readily available. Look for them at pet stores, Online vendor catalogs and Internet community forums.

Water Hyssop (Bacopa sp.)

A half-dozen or so Bacopa species are commonly used in planted aquariums. Their small, neat, rounded leaves function well as accents and as a means to soften transitions between groups of larger, bolder plants. Most Bacopa are easy to grow and can be kept either as underwater or emersed plants. The most common aquarium species, B. monnieri, transitions readily when switched between these two conditions, although humidity should remain high while it adjusts to growth in the air.

When used in combination with a Hanging Planter and a Trellis Raft, Bacopa plants create pleasing carpeting effects as they creep forward to cover the raft with their viny stems. In this way they help to develop the riparium composition midground, while also obscuring the Hanging Planters that hold neighboring plants. The way that such a Bacopa “lawn” softly transitions from the rear of the aquarium space to the open water in the foreground creates a very realistic semblance of how similar small stem plants grow from the edges of ponds and streams. This planting method is highly recommended.

Bacopa are readily available in the planted aquarium hobby.

Conclusions

The practice of tending of plants in ripariums presents many new possibilities for aquascape design and application of plants that have been used little in planted aquariums. By experimenting with other promising varieties–those that can grow with their foliage in the air, but their roots in saturated soil–you might find other plants that grow well in ripariums and help to create beautiful model riparian ecosystems.