2008 list
Updated 13 March 2008
The Restionaceae is a
family of rush like plants largely from the southern hemisphere. In
Restios -- or
the species offered here-- are plants that appreciate acid soils of low
fertility. January 2007 provided useful cold hardiness information on many
species—night temperatures were 20 degrees F. or lower for quite a few days
here.
Best germination comes when seeds are treated with
"instant smoke" prior to planting, and when they experience a marked
difference (30 degrees F. is ideal) between day and night temperatures after
they are sown. Best in soils low in
phosphorus.
All restios offered here
are from
Cannomois grandis - This giant bamboo like clumper makes thick culms which are pink to red in color
when they are new. Can reach 10'.
The very large seeds of this species have been difficult to germinate even
after treatment with 'instant smoke', 10 % germination typical. Previously
well known as Cannomois virgata. No damage at 20 degrees F. 50 seeds
Chondropetalum elephantinum - The big form of what has
been known as Chondropetalum tectorum for
years. Dark green erect culms are banded with chestnut bracts, which peel off
to reveal their shiny golden undersides as culms mature. Eventual size is 5'+
tall. Can grow in water or with drought.
One of the hardiest (known in cultivation) species -- seemingly untouched in
the severe freeze of 1998 in inland valleys in the
Ischyrolepis sieberi- A mounding species to 3' high with smooth green stems. Great for larger landscapes. Not as
sculptural in form as some species, but it makes attractive large bright green
mounds and is from higher altitudes, so may have increased hardiness. No damage
at 20 degrees F.
Ischyrolepis subverticillata - One of the best for cut
stems, even small portions of a stem have great symmetry and beauty. Can reach
6' high and densely clumping, this species will also thrive in part shade. Has
bright green culms and darker branchlets, with the
form of the branched horsetails (Equisetum),
but much stiffer, and of course, not running. Some plants quite damaged at 20
degrees F., others were untouched. 30
seeds
Restio quadratus -- Square
stems distinguish this restio from most others. It
forms great clumps to 5-6’ high, with branched (fluffy) culms that droop at the
tips, creating broad clumps. Not for the smaller gardens. Some damage at 20
degrees F.
Restio similis – Small clumping species to
18”. Dark green stems, with branched culms, shining bronze flowers in summer.
Rhodocoma capensis - Tall, erect columns of
branched "horsetail" dark green stems droop at their tips. Small
flowers are golden and line the branch tips. This is very graceful in form and
creates great contrast with all other plants. Clumps here are 6'+ at present
and are a visual treat in the garden. Untouched at 20 degrees F. 100 seeds
Rhodocoma foliosa – Erect bright shiny green clumps
have well branched culms. Golden male flower stems drape with an intricate lacy
appearance; female flowers are more subtle. To 5’, with erect rather than
drooping habit. Similar to Rhodocoma gigantea though
smaller in stature, and spreading a little more. Significantly damaged at 20 degrees F.
Rhodocoma gigantea – Dense,
springy foliage mass to 4’ or so; fl. stems rise far above the vegetative
clump. Male flowers on 6’+ stems, with
drooping Briza-like
effect; ephemeral female fls. are pink when they are actually open. Damage at
20 degrees F., with quick recovery. 30 seeds
limited supply
Thamnochortus acuminatus - This is a small (1 ft. to 1.5
ft tall by 1 ft. at base) densely tufted plant with finely branched stems
plumed with silvery bracts from NW mountains of the Western Cape, where it is
listed as rare. It has a medium to slow growth rate. Seed of many Thamnochortus
have low viability rates, but seed offered here have been hand extracted to ensure high
viability. 8-10 seeds per packet
Thamnochortus bachmannii
- This species only reaches 2'+. Green culms are branched, but flower stems
that rise over the foliage mass are naked and quite graceful. Golden bracts on the flowers. No
damage at 20 degrees F.
Thamnochortus insignis - One of the best restios for its architectural grace in the garden. Forming a hemispherical kinetic sculpture in time
with its slender gray green stems moving with the slightest breeze.
Stems can be 5' in length and rise from all points of the dense basal clump.
Golden flowers tip these branches. This is the only species observed to reseed
in a limited way in the garden. Good container plant. No damage at 20 degrees F.
Thamnochortus rigidus - Another small restio, this one is a dense, springy, interlocked foliage
bun to 18". Flower bracts are silvery and held over the tight foliage. No
damage at 20 degrees F.
Thamnochortus schlecteri - A mix of well branched dark
gray-green stems (fluffy) and naked flower stems topped with dark bracts. This
species is still developing its eventual form, but should stay 2' or less. No
damage at 20 degrees F.