‘Desert Island’ Survivors: Plants That Stand Up to Our Summer Heat
by Tom Spencer / Soul of the Garden
Yucca pallida in the foreground with Angelita Daisy.
When I designed my garden I divided it into two general zones: one that would be
irrigated and another that would have to fend for itself through the vagaries of
Austin’s brutal summers. Initially, I thought that the irrigated beds would be
the fun ones, where I could show off a wide selection of really cool plants.
Much to my surprise, my “desert islands,” the beds that I never water, have
turned out to be my favorites. These beds support a wide range of plants, bloom
year-round, and require minimal care. What’s not to love?
One of the keys to creating successful desert beds is preparing the soil well.
For folks who live in the Hill Country with its quick draining caliche, this is
less of a concern. But for those of us who garden in clay, a raised bed loosened
with lots of rock minerals and a little compost is essential. This helps the
plants stand up to the occasional monsoon, which would otherwise drown them. My
desert beds contain a mix that is about seventy-five percent mineral content
(decomposed granite, greensand, and other minerals) and twenty-five percent
compost. This loose mix makes planting and weeding a breeze and you can mulch
the beds with more granite or river stones to complete that desert look.
Good Life regulars are by now well aware of my predilection towards the prickly,
namely the Agave clan, and these plants are often the centerpieces of my desert
beds. (See last month’s article.) However, I have found a wide selection of
supporting characters that could easily be cast in the starring role of your
gardens. Like the Agaves, many of these plants have striking sculptural forms
while others bloom almost year-round.
The Yuccas have suffered from some of the same bad PR that affects the Agaves,
namely most of us are only familiar with the few rather ominous species that our
parents gardened with. Anyone who spent a childhood in Texas grew up respecting,
if not dreading, the ubiquitous Spanish Daggers (a common name for various
Yuccas) that were planted in many a nineteen-fifties and–sixties landscape.
These were great plants for preventing home break-ins but made for painful games
of hide and seek.
Fortunately, there are many cool, and much less murderous, Yuccas that are now
commonly available in local nurseries. My favorite of these is Pale-Leaf Yucca
(Yucca pallida) a beautiful native to North Central Texas that has soft bluish
foliage. This trunkless compact plant makes a wonderful addition to the front of
your beds where it mixes well with hardy wildflowers. It blooms in mid-spring,
sending up a tall spike of beautiful waxy blooms. Pale-Leaf Yucca often
hybridizes with one of the dominant native Yuccas of our area, Twist-Leaf Yucca
(Yucca rupicola) to striking affect.
Banana Yucca (Yucca baccata) does have foliage with sharp pointed tips, but
unlike the Spanish Daggers mentioned above, the foliage arches downward
gracefully, so the effect isn’t quite as bristly. What I like about Banana Yucca
is the color of the foliage, which is a very pale sage green, and its compact
form—it rarely grows more than three feet tall.Like the Pale-Leaf Yucca, Banana
Yuccas send up a tall white flower spikes in the springtime. (The common name
comes from the fruit of the plant, which follows the bloom and resembles a
miniature banana.)
Red Yuccas (Hesperaloe parvifolia) are not true Yuccas at all and are much more
closely related to the Aloe clan. These plants are longtime favorites in Austin
area gardens with their coral-pink blooms carried on tall flower spikes above a
fountain of shorter spine-less branches. In recent years, a new color form has
been made available that I really love; it is a pale sulfur-yellow that really
pops out in the landscape. Both color forms are very attractive to hummingbirds
and the blooms last for months.
Giant Red Yucca (Hesperaloe funifera) is a knockout. The tall strap-like foliage
of this plant is very upright and ends in a soft tipped point. The effect is
very bold, providing year-round interest. The flowers are borne on tree-like
shoots (complete with branches) that can rocket up to ten feet in just a few
weeks. The long-lasting blooms are mostly white though they have a touch of pink
to them. This plant is destined to be a superstar addition to the Texas plant
palette.
The plants referenced above provide strong sculptural forms for garden beds. I
like to surround these with colorful perennials that have a softening effect.
One of my favorites of these is Angelita Daisy (Hymenoxys acaulis), a very
compact plant that has a little tuft of grey-green leaves. The yellow daisy-like
blooms rise above the foliage on single stems that grow eight to twelve inches
tall. In the right kind of growing conditions, this tough little Texas native
reproduces quickly, sending up volunteers that are very easy to control.
Angelita Daisy blooms nearly year round and requires only occasional
dead-heading (removal of spent blooms) to look its best.
Pink Skullcap (Scutellaris suffrutesscens) is a low mounding perennial that is
usually evergreen in Austin gardens. When planted in groups, Pink Skullcap
resembles a green pillow that is covered with tiny leaves and deep pink blooms.
Like the Angelita Daisy, Pink Skullcap blooms for a very long time, from early
spring to late fall. During the winter, it can look a little rangey, but an
early spring trimming will restore it to its best form.
Call around to our locally-owned nurseries and you should be able to find all of
these summer-loving “desert island” plants. These are the guys who really know
how to play survivor.