Plant of the Month (November) : Clustered (California) Field Sedge

Clustered field sedge (Carex
praegracilis) - Mother Nature's Backyard

Few
plants are blooming now in Mother Nature’s Backyard. And those that are have already been featured
as Plants of the Month. But one of our
favorite ground covers is perking up with the recent rains and cooler
days. So we’ve chosen Clustered field
sedge (Carex praegracilis) as our
Plant of the Month. The species name is
pronounced CARE-ex pre-GRASS-ill-iss.

The
sedges (genus Carex) are perennial,
grass-like plants that grow in climates ranging from the tropics to the tundra;
sub-Saharan Africa is the only continent with few species. Most of the several thousand species grow
in boggy, marshy places or near ponds and streams, but some are more drought
tolerant.

There
are over one hundred and thirty Carex
species native to California, the vast
majority growing solely or mostly in the Sierra Nevada Mountains or the
mountains of N. California. However, about
20-25 species are native to Los Angeles County or the S. Channel Islands. [2] While
most of them grow only in the San Gabriel Mountains, a few can be found in the
lowlands as well. Carex praegracilis is one of them.

Clustered field sedge (Carex praegracilis) - good example

of California native sedge

The
leaves of sedges are long, narrow and grass-like. In fact, many people mistake
sedges for grasses. But sedges are actually close cousins, belonging to a
different family entirely (the Cyperaceae)
and having flowers quite different from those of the grasses. In fact, the
flower stalks of the sedges are triangular in cross section.

The
old saying 'sedges have edges, rushes are round, grasses have knees that bend
to the ground' helps one remember a key difference between the grass-like plants.
Most sedges spread by rhizomes (underground
stems), stolons (‘runners’) or roots, forming a lawn-like sod. Sedges are used in some areas as a substitute
for lawn grasses.

Clustered
field sedge has a wide geographic range – from mid-western U.S. to the west
coast. In California, it grows in the
California Floristic Province and desert mountain ranges, from sea level to
about 7000 ft. (2500 m). It once grew
along the LA River, Ballona Creek and marshes, on Santa Catalina Island and in
the Liebre, Tehachapi and San Gabriel Mountains. [3] It likely was common, but unrecorded, in many
other moist places in the lowlands of western Los Angeles County. In S. California, it occurs in/near both
freshwater and alkali wetlands, including those that are only seasonally wet.

Clustered field sedge (Carex praegracilis)

In
the horticultural trade, Carex
praegracilis is sometimes confused with (and sold as) Carex pansa, a shorter species native to several areas along
California’s central and northern coast.
Both are similar in appearance and use in the garden. But there are important differences between
the two, including size: Carex pansa
is only about 6-8 inches tall, while Carex
praegracilis is slightly taller. For
a great discussion of the two species (and how to tell them apart) see
reference 4, below.

Clustered field sedge (Carex praegracilis): fine-textured

foliage

Clustered
field sedge is a perennial with narrow, bright to medium green leaves typical
of sedges. The leaves are slightly more narrow and longer than Carex pansa. It grows about 1-2 ft. tall and looks
superficially like a fine-bladed grass.
In fact, the species is commonly used as a grass substitute. It spreads via stout, dark rhizomes
(underground stems) to form a sod-like mat.

Clustered field sedge (Carex praegracilis): spreads by

rhizomes to create a sod-like mat

This
species is a very useful addition to local gardens. It tolerates full sun to part-shade. We’ve found it looks best in part shade, and
even have a nice stand growing north of a 10 ft. wall in Mother Nature’s
Backyard (see below). Carex praegracilis does fine in most
local soils, from sandy to clay (we’ve grown it in both extremes). It doesn’t mind the alkali soils found in
some parts of our region.

Clustered field sedge (Carex praegracilis): in shady

position with Feltleaf everlasting

Clustered
field sedge really needs no added fertilizer, though it probably wouldn’t harm
it. While young plants need regular
water, established plants are quite drought tolerant. Carex praegracilis can get by with infrequent irrigation (deep
watering several times a summer), though plants will go dormant. To keep established
plants green, water every 2-4 weeks, depending on soil type. Taper off water in the fall, to give plants a
bit of a rest.

Clustered field sedge (Carex praegracilis): naturally

dormant under dry conditions

Like
most Carex species, Carex praegracilis is
best started as a purchased plant or as plugs.
In our experience, Clustered field sedge spreads more slowly than Carex pansa, taking several years to
really establish in western Los Angeles County.
It may fill in more quickly in wetter regions (or with more irrigation
than we give it). If used as a lawn substitute,
we suggest planting plugs 8-10 inches apart.

Carex praegracilis is a cool season, sod-forming sedge,
so it does most of its growth in winter and spring in lowland S.
California. It blooms in late spring or early summer. The blooms, on stalks that are somewhat taller
than the leaves, are pale green, fading to tan fruits with white tips. The
flowers and fruits are not particularly noticeable, although characteristic of
the species; we’ll get some photos next year.
For good photos see reference 5, below.

Clustered field sedge (Carex praegracilis): nice

natural groundcover

Clustered
field sedge is worth considering when you want the appearance of ‘grass’ in an
easy care, water-wise native. It’s very
low maintenance; all that’s needed is to cut back to remove the brown foliage
(if any) in late fall. If it spreads into
areas where it’s not wanted, just pull out the young plantlets.

Clustered
field sedge makes a good natural lawn substitute, and established plots can
even be mowed (4-6 inches) several times during the growing season. Sedge lawns
can be walked on, though probably not the best choice for heavy use. The sod grasses are still the best option for
playing fields and other heavy traffic areas.
But if you just need a water-wise, decorative green ‘lawn’, Carex praegracilis could be a good choice.

Clustered field sedge (Carex praegracilis): low maintenance

We
like Clustered field sedge left un-mowed, allowing it to form a natural
groundcover under and around trees/shrubs. It is a great natural groundcover
for vegetated (infiltration) swales, and can be mixed with other groundcovers liking
seasonal water. It does well on slopes and can be very useful
there. If watered, it can be used as a
fire-resistant buffer plant in fire-prone areas. You can even grow it in a pot for spot of greenery
on a shady porch.

Incredibly
adaptable and drought-resistant, Carex
praegracilis may be just the plant you need to create a ‘green oasis’ in
your water-wise garden. It’s locally native, delicate of appearance, yet tough
as nails. It fills in between plants,
providing needed contrast for other native plants. We couldn’t garden without it!