By Larry Hodgson
This popular houseplant suffers from a bit of brand confusion: I mean, the botanical name isn’t a problem: Cyperus alternifolius is generally accepted, although one does hear C. involucratus, it’s former name, still used. But it has too many common names. All include the word “umbrella,” due to its linear green grasslike leaves borne in a whorl at the tip of the thin green stem, like the spokes of an umbrella.
The names include:
- Umbrella palm: probably the most common name, but it’s not a palm nor in any way related to a palm (Arecaceae), so…
- Umbrella grass: it is indeed very grasslike, but it’s not a member of the grass family (Poaceae) either, so…
- Umbrella plant: that would be appropriate, but the name is already taken, what with the more popular Schefflera also going under that name, so…
- Umbrella sedge: my favorite name, as it is indeed a sedge, being a member of the Cyperaceae (sedge family);
- Umbrella papyrus: it is certainly a very close relative of the papyrus plant (Cyperus papyrus), described below, and it would be easy to make an argument for that name, but… I prefer umbrella sedge and since I’m writing this article, that’s the name I’ll use here.
This foliage plant grows as a clump of upright cylindrical green stems up 4 to 6 feet (1.2 to 2 m) tall, each topped with the aforementioned whorl of 10 to 25 flat leaflike somewhat drooping bracts.
Short stems of cluster yellow-green flowers eventually turning brown appear from among the bracts during the summer months. The flowers are not unattractive, nor are they stunning, but do add interest to the plant. They eventually release seeds that can sprout in nearby pots.
The umbrella sedge divides abundantly at the base, so the original small clump can grow to entirely fill its pot.
This semi-aquatic plant originally grew wild throughout much of tropical Africa, Madagascar and the Arabian Peninsula in fresh-water wetlands, along rivers, in ditches, etc. It has since naturalized in many tropical countries all over the world. It doesn’t escape from culture in more temperate climates, though, as it is not frost hardy.
The genus name Cyperus comes from the Ancient Greek “kúpeiros” for sedge, while alternifolius is Latin for “with alternate leaves.” The genus contains over 700 species and is found all over the world except Antarctica, as some are tropical climates and others adapted to temperate climates.
The species itself (C. alternifolius) is actually rarely grown indoors, although it’s frequent outdoors in tropical climates. It’s just a bit too big to place on most windowsill sills!
Dwarf Umbrella Sedge (C. alternifolius ‘Gracilis’): What you usually see in homes is this dwarfer, more delicate-looking variety, usually around 18 to 36 inches (45 to 90 cm) tall with fewer and narrower bracts. It comes true to type from seed.
Variegated Umbrella Sedge (C. alternifolius ‘Variegatus’): This is also a modest-sized variety, usually about 18 to 36 inches (45 to 90 cm) tall, although under truly tropical conditions, it can become much taller. It produces irregular white stripes on the both the stem and the bracts and can be quite striking. It tends to revert to the all-green form, so prune out any entirely green stems. It doesn’t come true from seeds, nor even from cuttings. They usually give either all green plants or albino ones with no green at all. You need to propagate it by division.
Zumula Cat Grass (C. alternifolius ‘Zumula’): This extra dwarf cultivar (rarely more than 10 inches/20 cm tall) is being sold as cat grass. Of course, other plants are sold as cat grass, notably oats (Avena sativa), but these are annuals and need to be sown over and over. ‘Zumula’ will instead act like a cut and come again lettuce: the more kitty chews on the top, the more it will sprout from the base. You can keep it going for years!
Broadleaf Umbrella Sedge (C. albostriatus, sometimes sold as C. diffus): This is a very different species in many ways: shorter (the variety usually seen is actually ‘Nanus’, about 12 inches/30 cm tall), with broader leaves, a triangular stem (not cylindrical like C. alternifolius) and a distinct cluster of green leaves at the base of the stems. This is a much more terrestrial plant than the usual umbrella sedge. Do keep it relatively moist, but never submerge its crown in water. It doesn’t multiply readily from stem tip cuttings and is best propagated by division.
Variegated Broadleaf Umbrella Sedge (C. albostriatus ‘Variegatus’): This is a variegated version of the previous plant and probably the most widely available variegated umbrella sedge. The variegation is more cream than white and tends to blend into the green somewhat, so isn’t as striking as that of variegated umbrella sedge.
Papyrus (C. papyrus): I’ll only briefly mention papyrus here, as it is too big (5 to 8 feet/1.5 to 2.5 m in home settings, up to 15 feet/5 m outdoors in the tropics) to make a good houseplant and doesn’t do well indoors anyway, preferring a cool yet frost-free winter and especially, intense sun, so hard to supply to such a large plant during the short days of winter. It produces thick creeping rhizomes and equally thick, sturdy, triangular stems, each bearing a considerable cluster of threadlike rays (the real leaves are few and difficult to see) at the top, looking for all the world like a green feather duster.
Cyperus papyrus is the plant the Egyptians used to produce one of the world’s first papers: papyrus!
There are smaller varieties of this plant, like ‘Little Tut’, but all are really much happier outdoors as a perennial in tropical climates or as a summer annual in temperate ones than indoors. At best, you can overwinter them indoors, but they’re rarely very attractive inside the house.
Papyrus will grow as either a terrestrial or semi-aquatic plant, but if you grow it in a pot, preferably you’d keep it at least soaking in water, as it will not tolerate drying out entirely. If you manage to keep yours alive indoors over the winter, you can multiply it by division.
Dwarf Papyrus (C. haspan): This species, with its triangular stems and threadlike rays does indeed look like a shorter (12–30 inches/30–75 cm), less dense papyrus with tiny green flowers turning brown at the tips of the rays. One telling trait is that each stem top has one or more long leaflike bracts just under the thin rays. Dwarf papyrus makes a very good houseplant and can be grown much like C. alternifolius.
Invasive in the Wild?
This article is about houseplants, so this won’t be a problem indoors, but in case you’ll be planting any of these plants outdoors in a mild climate (most will only grow in USDA hardiness zones 9 or 10 to 12), all Cyperus species described here are likely to be at least a bit invasive when planted outdoors. In fact, most are now well established as naturalized plants well beyond their original range in various countries all over the world.
Caring for an Umbrella Sedge
The umbrella sedge is not a difficult plant to grow indoors, but it is definitely not your typical houseplant. You do have to meet its very particular needs if you hope to succeed.
Watering: And watering is what makes or breaks this plant. Theoretically, you could water it just like any other houseplant, setting it in a saucer and watering when the soil is dry to the touch, but umbrella sedge uses up water so rapidly it can go from “just a bit dry” to “dead” in only a few hours. You’ve never seen a plant “drink” so much!
So, the wise gardener will offer it a different treatment: that is, letting it soak constantly in water. This would be an anathema to 99% of other houseplants, but there has to be an exception to every rule, doesn’t there? Well, here is one!
You could put your umbrella sedge in a regular plant saucer and keep topping the saucer up, but I suggest putting its grow pot (the pot with drainage holes that you actually grow the plant in) into a cachepot (a pot without drainage holes) at least 4 inches (10 cm) wider than the grow pot and then filling the cachepot with water to near the brim. After that, you only need to top up the cachepot before the water level drops to nearly nothing. That way, you should be able to go a week or so without having to water again.
Since the umbrella sedge is semi-aquatic, it will even grow with its crown entirely covered with up to 6 inches (15 cm) of water.
Do change the water twice a year or so to prevent mineral salts from building up.
Helpful Hint: This is a great plant for people who tend to overwater. You simply can’t overwater an umbrella sedge. Every time you walk by it and see the water level has dropped even slightly, you can add more water if you want to!
You could also grow umbrella sedge in an indoor water garden, as long it receives enough light. It cohabits perfectly with fish, for example.
Light: Bright to medium light with at least a few hours of sun per day will work well. Full sun all day every day is probably best of all. It will decline and etiolate, with weak stems that don’t stand upright, if the light is too low.
Humidity: The umbrella sedge will put up with fairly dry air, but that can result in brown leaf tips and possibly spider mites. It will easily take all the humidity you can give it: relative humidity of 70%, 80% or more!
Helpful Hint: This plant is a natural air humidifier, drinking up water like a fish, then releasing the most of it into the air. If you have enough of umbrella sedges in a room, you won’t need a air humidifier!
Fertilizer: Any all-purpose fertilizer applied at a low dose (perhaps a quarter of the recommended rate) will suffice to keep it green. Too much fertilizer tends to result in floppy stems and spider mites.
You can add liquid fertilizer directly to the water, apply granular fertilizer to the soil or insert waterlily tablets into the potting mix. Apply fertilizer only during the main growing season, from early spring to fall.
Temperature: It’s perfectly adapted to average home temperatures, but try to keep it above 55˚F (13˚C) at all times.
Grooming: There can be quite a lot of it.
Clip off any old, yellowing stems and any brown leaf tips and cat damage. Once you’ve trimmed off most of the leaf tips from any given stem and it’s no longer attractive, cut it off too. If the whole plant has become a shaggy mess (and it can do that if you don’t keep on top of things), shear the whole thing to the base and it will grow back surprisingly fast.
This plant produces an insane quantity of roots, far more than it could possibly use, and if allowed to run loose, will fill your cachepot with them. It’s best to pull the grow pot from the water every 4 to 6 months and clip the roots well back, right to the pot if you want to. Don’t worry! They’ll be replaced soon enough!
You may find you need to weed nearby houseplants, as the seeds of the umbrella sedge tend to germinate in neighboring pots. If you see little grasslike plants popping up in the spring, they’re probably baby umbrella sedges. They rarely live long, though, as conditions in most houseplant pots are too dry.
Repotting: Calculate how wide you want the plant to become and plant it in a pot of that diameter: it will fill it right to the edge on all sides. Every 4 or 5 years or so, divide the plant and repot.
Use any potting soil you wish. After repotting, you’ll need to wait a few weeks for the roots to fill in and hold the soil in place before submerging the crown in water, or the soil will tend to float away. Or cover the soil with a pebble or clay pellet mulch to hold the soil in place.
Repot into a heavy pot, like terra cotta, or it’s not just the soil that may start to float, but the whole plant!
Multiplication: The main way of multiplying umbrella sedge in the home is by tip cuttings. Cut off the top whorl of a stem leaving about a 1-inch to 4-inch (2 to 10 cm) stub and set it upright, upside down* or sideways in a glass of water or press it into soggy soil. Some people trim back the leaves to about 1 inch (2 cm) or so in length before starting to root the cutting, but that really isn’t necessary. Roots will appear within a week or so, then baby plants a few weeks later. You can plant them right away into their future grow pot.
*There is a rumor circulating that umbrella sedge cuttings will only root when placed upside down. Ignore it!
Fun Fact: In the wild, umbrella sedge stems are often broken by wind, rain, birds or animals and thus bend over and touch the water that surrounds them. They then start to root, forming a new plant. Either these babies root on the spot or break free and float off to form a new colony elsewhere. This is the main way umbrella sedges spread in the wild.
Division is fast and easy too. Empty a plant from its pot, cut or saw the root ball into 2, 3 or 4 pieces or more, slicing from top to bottom, and pot up the resulting clumps.
Umbrella sedge is likewise easily multiplied by seed and seed is available from certain seed companies, notably on the Internet, or you can collect it from your own plants in late fall. Just sow it on the soil’s surface and keep very, very moist.
Any form of multiplication will go faster in the spring or summer. You may need to supply bottom heat and artificial light to succeed in the depths of winter.
Pests and Diseases: In many homes, the worst enemy of the umbrella sedge is the family cat. Cats are well known for nibbling on grass outdoors and seem to mistake this sedge for a grass indoors (and it is indeed a close relative). This doesn’t harm your kitty and is even be good for it. Of course, chewing too many leaves does tend to provoke vomiting … which doesn’t seem to bother the cat nearly as much as it does you.
The damage done to the plant is strictly esthetic and can be pruned off … or you could simply let your pet have its fun: nibbling on leaves is a sure cure for kitty boredom! Or move the plant somewhere the cat can’t reach it … best of luck with that!
Spider mites can proliferate in dry air, therefore mostly in winter, and cause stems and leaves to dry out and become covered with spiderlike webbing. They can be controlled by taking the plant to the sink and rinsing off the stems and bracts. You’ll need to repeat weekly for a while.
Other insects (aphids, mealybugs, scale insects, etc.) are possible, but are no more attracted to umbrella sedges than other indoor plants. You can use insecticidal soap, neem oil or some other mild pesticide to control them.
Umbrella sedge: a charming houseplant with unusual habits. Wouldn’t it look just lovely in your décor?