Adding grasses to your roster of pond plants is always a good idea! Grasses are great at naturalizing any outdoor feature. If you find that there’s a missing element to the edges of your wildlife or ornamental pond, or you simply have some vacant spots to fill in, definitely go for a few properly selected species of grasses. You’ll find that these will easily complement the leaves and fronds of other flowering plants.
Grasses can bring both aesthetic and environmental services to your pond or water feature. Height, texture, and ease of maintenance – you name it! They can be used to blur a pond’s edge, hide your liner, and contrast the appearance and colors of other inorganic features. They are also quite effective at holding the shoreline and preventing excessive soil erosion. This means that they can serve as a buffer and protect your pond from streaming rainwater and leeched soil nutrients.
If you want to attract wild visitors to your pond, you can be certain that a few grasses will help keep them protected and sheltered. Even aquatic grasses develop a profusion of leaves that can hide an assortment of animals, from small young frogs to large wading birds. Though grasses have the tendency to spread, they are seldom aggressive and may help control the growth of noxious weeds. Consult the list below for a selection of grass types that would thrive in either marginal or pond edge conditions.
1) Cattails (Typha spp.)
Cattails, also known as bulrushes, are a type of reed that seem to crop up around almost all naturally occurring pond systems. It’s highly likely that if you have someone illustrate a pond in the wild, they’ll add a few cattails along the edges of their drawing, just for good measure. This grass has notable features, one of which is the seed stalk or flower head of the plant. These can deceptively have the appearance of furry tails as they sway gently in the wind.
The bright green leaf blades of cattails arise from stems that grow up to 2 feet tall. These are supported by extensive root systems with underground rhizomes. The roots are able to serve as filters, purifying your pond water of toxins and excess nitrates. All of these plant parts are actually edible and can provide many health benefits to both you and your pond visitors! Cattail species that would fair quite well in a marginal pond environment include the following:
- Broadleaf cattail (Typha latifolia)
- Narrowleaf cattail (Typha angustifolia)
- Hybrid cattail (Typha glauca)
- Southern cattail (Typha domingensis)
The only downside of growing cattails around your pond or bog is their capacity to spread. If your water feature is quite small, cattail populations can quickly overwhelm your pond edge. A good way to combat this issue is by restricting their growth to within pots! Just remember to remove the seed stalks before they spread their seeds in the fall!
2) Manna grasses (Glyceria spp.)
Known for their starch-rich grains, manna grasses are tall perennials that favor conditions in aquatic habitats or wetland areas. These are characterized by upright leaf blades that have either a folded or flat orientation. These tend to “nod” or fold downwards along the keel when the blades have grown too long or heavy. Manna grass seeds arise from distinct inflorescences that rise high above the leaf blades. The seeds are contained in spikelets that sway gently in the wind.
Manna grasses are perfect for the margins of your pond, rain garden, or water feature. Many species are adapted to having “wet feet” and can even withstand minor flooding events. They are quite hardy in terms of growth requirements. Common manna grasses seem to thrive in either standing or moving water and under a wide range of pH conditions. Their leaves perform best under full sunlight, however, and may be sensitive to frost. Listed below are a few species that should perform well in a pond edge setting:
- Float grass (Glyceria fluitans)
- American mannagrass (Glyceria grandis)
- Reed mannagrass (Glyceria maxima)
- Fowl mannagrass (Glyceria striata)
- Melic mannagrass (Glyceria melicaria)
Manna grasses are also a great way to add dimension to wildlife ponds and large ornamental fish ponds. At maturity, some species can reach a height of 4 feet or more. For this reason, they are perhaps less suitable for smaller ponds or water features. It is also important to keep in mind that some species have the potential to be invasive when reared outside of their native range. This type of grass can spread quickly and may have to be grown out of pots to prevent competition with native grasses.
3) Horsetail (Equisetum hyemale)
As far as rushes go, horsetail is quite unique. This species can bring a zen-like element of calm and order to your pond or water feature. Also referred to as snake grass or scouring rush, horsetail favors the moist to wet soils of riparian forests, marshes, and swamps. Its roots and modified stems are able to withstand occasional flooding and can thrive in setups with standing water.
Horsetail can look quite similar to bamboo. It isn’t a type of grass in the true sense, but its uses are remarkably similar to those of ornamental grasses. To complicate things, its mechanism for reproduction is more similar to that of a fern! It produces spores and spreads via rhizomes underground. All things considered, cultivate this species as you would grasses around your pond and it will unfailingly catch your eye every time.
Once established, horsetail can grow to a height of up to 6 feet! Look closely at the hollow, seemingly segmented stems, and you’ll find that there are tiny leaves hugging each of the black to dark green joints. The shoots can grow closely to one another and become dense. A colony can quickly spread to look like a miniature wall of green posts, especially when grown out of elongated pots.
4) Papyrus (Cyperus spp.)
The cool thing about papyrus is there are several species and cultivars that differ in height. This means that, whatever the extent of your pond, there is likely a papyrus variety that would complement its size without stealing the show or providing excess shading. This opens up endless possibilities for design, as the varieties can be mixed and matched with sculptural pots and elevations.
The typical papyrus plant (Cyperus papyrus) can tower to a height of 5 – 8 feet. It produces triangular shoots, at the tips of which arise clusters or thin rays that can be likened to fireworks or feather dusters. At maturity, flower clusters appear at the tip of each ray. The overall appearance is very decorative and can overwhelm a small water feature. Here are some other shorter cultivars and closely related alternatives to look out for:
- Dwarf papyrus sedge (Cyperus papyrus ‘Nanum’) – 2 – 3 feet tall; recipient of the RHS Award of Garden Merit
- Giant dwarf papyrus (Cyperus percamenthus) – 2.5 – 3 feet tall
- Umbrella sedge (Cyperus alternifolius) – 2 – 5 feet tall
- Dwarf umbrella sedge (Cyperus alternifolius ‘Gracilis’) – up to 2 feet tall
Papyrus belongs under Cyperaceae, the large family of sedges. It is not considered a “true grass” but is nonetheless a close relative. Hardy to USDA zones 9 – 10, papyrus plants thrive best under full sun and in shallow, relatively warm water. The shoots benefit from ambient temperatures that range from 20 to 30˚C (68 – 86˚F) and are unable to tolerate frost. When conditions are optimal, this plant has the potential to become invasive. You may opt to grow your papyrus plants out of containers to restrict their spread.
5) Sweet flag (Acorus spp.)
If you’re after low-growing grasses that would make good ground covers, you must consider growing sweet flag. This grass is characterized by fine, sharp-edged leaf blades that vary in color and variegation depending on species and the specific cultivar. Generally, wild sweet flag grasses have plain, green leaves that are great for adding texture to a pond or water garden’s edge. For more color, look into these showy cultivars:
- Variegated sweet flag (Acorus calamus ‘Variegatus’) – has cream and light-yellow lengthwise stripes; 2 – 4 feet tall
- Golden grassy-leafed sweet flag (Acorus gramineus ‘Ogon’) – has bright lemon-yellow leaves with green stripes; grows up to a foot tall
- Dwarf golden sweet flag (Acorus gramineus ‘Minimus Aureus’) – produces either light-yellow or lime-green leaf blades; clumps grow to just 4 inches tall
To ensure that your sweet flag grasses continue to produce bright leaves, you must situate them in moist or wet soil. If the soil dries up, the leaf blades can grow scorched. A marginal or pond edge location that receives at least 6 – 8 hours of sunlight would work best. One of the perks of cultivating sweet flag is its ease of propagation. It gradually spreads via rhizomatous growth, but does not tend to grow as aggressively as other grasses.
Hardy to USDA zones 6 – 9, sweet flag thrives best in hot and humid weather. When conditions are optimal, it produces tiny blooms in spring. This grass has earned its common name not for its appearance or growth habit, but for the “sweet” fragrance that emanates from bruised leaves. Don’t let the fragrance fool you though, as this plant is toxic to both animals and humans!
6) Carex sedges (Carex spp.)
There are over 1,500 species of Carex sedges, and most of them favor the moist conditions of wetland areas across the globe. These true sedges are perennial plants that have both ornamental, restorative, and medicinal uses. Many species are prized by the horticultural community for their highly textured and multicolored tufts of leaves. These sedges certainly have character! Known for their attractive features, here are some of the most commonly cultivated species and cultivars:
- Bowles’ golden sedge (Carex elata ‘Aurea’) – recipient of the RHS Award of Garden Merit
- Blue sedge (Carex flacca)
- Japanese sedge (Carex oshimensis ‘Evergold’) – recipient of the RHS Award of Garden Merit
- Leatherleaf sedge (Carex buchananii)
- Creeping broad-leafed sedge (Carex siderosticha ‘Banana Boat’)
Carex sedges typically spread via rhizomes and stolons. Their flat leaves arise from short stalks and are comprised of both a blade and a sheath. Unlike true grasses, Carex sedges have triangular stems that may bear tiny floral inflorescences in spring or summer. Depending on the species, the plant’s best features may be brought out in shaded areas or along the borders of water features that receive full sun.
If your pond is relatively small and has sections that would ideally be complemented by low-growing plants, you should definitely consider growing Carex sedges. Unlike many grasses, Carex tufts tend to have a maximum height of 2 – 3 feet, with some averaging at just a foot tall. They are quite tame in terms of spread and are not known for being aggressive growers.
7) Woodoats (Chasmanthium spp.)
Woodoats is a collective term for grasses that belong to the Chasmanthium genus, which falls under the Poaceae family of true grasses. The most notable feature of these grasses is their flat seed head, which resembles those of oat plants. These seed heads tend to be quite pale, large, and droop downwards. They appear during spring, when conditions are optimal for pollination and seed production.
The most commonly grown woodoat is Chasmanthium latifolium. This species is also referred to as northern sea oats or Indian wood oats. It is popular in the landscaping industry due to its tolerance for a wide variety of sun exposure types and soil moisture levels. C. latifolium can serve as a tall ground cover plant in shady areas around your pond. Every summer, you can collect its seed heads and use them in flower arrangements!
8) Common rush (Juncus effusus)
Juncus effusus is often referred to as common rush or soft rush. This flowering perennial favors environmental conditions in wetland areas and can grow vigorously when nutrients are readily available. It provides many vital services to local fauna, as its tall leaves and root stalks are edible (potentially toxic in large quantities) and have many medicinal uses.
Common rush is a great plant to have around a wildlife pond because many native wildfowl and riparian species are familiar with using its fronds for protection and for creating nesting habitats. It can also attract a number of insects, particularly the rufous minor moth which feeds on grasses. If you’re interested in luring beavers to your wildlife pond, grow a few clumps of this species as it is commonly found in beaver dams!
Hardy to USDA zones 4 – 9, common rush is generally easy to cultivate. It thrives under both full sun and partial shade exposure. It grows best in rich, moist soil but can also occasionally tolerate being in a few inches of standing water. Keep in mind that this species has the tendency to spread quite quickly via rhizomatous growth or by self-seeding. Consider restricting its spread to within pots to leave room for other native plants around your pond.
