The spikelets of Purple nutsedge (Cyperus
rotundus, Cyperaceae) carry the flowers. The ‘hairs’ are the male anthers.
It is one of the most advanced land plants on Earth, being independent of
insects for its pollination (it uses the wind) and independent of fungi for
its mineral uptake (no mycorrhiza). A medicinal plant to some, a cheap
substitute for grass to others, or the world’s most serious weed? It is all
in the eye of the beholder.
One option is to plant no grass at all, and simply mow
whatever comes up (saving 80 000 Baht plus costs for transportation and
working crew). From experience at Dokmai Garden, if you simply water and
mow, the survival of the fittest will give you a green Chiang Mai ground
cover composed of e.g. Hard slitwort (Lindernia crustacea, blue flowers
resembling European Veronica from a distance), Haired slitwort (Lindernia
ciliata, white flowers), Singapore daisy (Tridax procumbens, yellow
nectar-rich flowers), Wild globe everlasting (Gomphrena celosioides, white
flower heads and edible leaves), Slender amaranth (Amaranthus viridis, an
edible plant), Tropical chickweed (Drymaria diandra, shade plant with edible
leaves), Dove weed (Murdannia nudiflora, pale blue flowers), White-headed
sedge (Cyperus leucocephalus, grass-like leaves, white flowering spikes,
triangular stems), Purple nutsedge (Cyperus rotundus, grass-like leaves,
brown flat spikelets, tubers used for making perfume, medicinal), Garden
spurge (Euphorbia hirta, an antiviral plant used to treat Herpes blisters),
Three-flowered beggarweed (Desmodium triflorum, clover-like, blue blossom,
nitrogen-fixing), Natal grass (Melinis repens, an African grass),
Missiongrass (Pennisetum polystachyon, a grass from western Asia),
Kiss-me-quick (Portulaca pilosa, a creeping succulent with red flowers), Old
world diamond-flower (Hedyotis corymbosa, white flowers, squarish stem) and
Brazil pusley (Richardia brasiliensis, white flowers).
If you have neighbours with the commercial grass ‘ya malesia’ (Carpet grass,
Axonopus compressus) then it will spread by seed into your garden too. Since
it is quite competitive, especially in light shade, you may eventually have
a lawn without any effort or costs.
Unwanted plants which can survive the mower are Sensitive plant (Mimosa
pudica, fun in the beginning until bare feet bleed from prickles and other
plants are pushed out) and Crab grasses (Digitaria spp.). If you do not want
them they should be pulled up by hand. Begin pulling early in the
establishment of the new garden and they will never be a problem, begin a
year later and they will always inhabit your garden.
One comment is that the chemical industry (not so much Monsanto here in
Thailand but the many Chinese copy cats) makes tonnes of money selling
glyphosate (Roundup and its copies) and other chemicals to wipe out sedge
(Cyperus spp.). If you just want a green cover and do not care what is
growing there, or if you are thrilled about biodiversity and like a mosaic
of foliage and cute little blossom, then save the money and reduce the use
of industrial chemicals.
Another option to grass is to get another ground cover, such as forage
peanut (Arachis pintoi and related species).
If you do not mow, plow or graze, any spot with sun will be covered with
tall American weeds such as Mikania micrantha, Chromolaena odorata, Mimosa
pigra and Mimosa diplotricha. Good luck, have fun, and remember that
everything you like in your garden is correct design.