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| Guadalupe Island rock daisy (Perityle incana; yellow) in Mother Nature's Backyard |
The
between-season periods can be a challenge for those who love color. That’s why season spanners like Perityle incana, with their long bloom
period, are so appreciated by local native plant gardeners. While Perityle
incana technically doesn’t hail from California, it’s a water-wise sunflower
(family Asteraceae) that’s often
included among the California natives.
Guadalupe
Island rock daisy is endemic to Isla Guadalupe, an island off the northern coast
of Baja California. The Baja Channel
Islands (including Isla Guadalupe) have an interesting relationship with
California. In fact, they share a
complex geologic history, full of movement, volcanic eruptions and more. To learn about the geology of the California
coast we recommend: http://www.nps.gov/chis/photosmultimedia/models-of-change-geology.htm
Northern
Baja California (including the northern Baja Channel Islands) represents the
southernmost extent of the California Floristic Province, an important biodiversity
hotspot. The coastal islands themselves are
home to many unique species and sub-species, in large part due to their long separation
from the mainland. For more on the California Floristic Province
see: http://en.wikipedia.org/wiki/California_Floristic_Province and http://www.calacademy.org/exhibits/california_hotspot/overview.htm.
Guadalupe
Island rock daisy grows in the washes, canyons and bluffs of Guadalupe
Island. Guadalupe is a 100 square mile
volcanic island located approximately 150 miles from the Baja coast. It’s home to 34 unique plant species as well
as endemic birds and invertebrates.
Among the plants are unique pines, cypress and oak in addition to
smaller plants. Severely degraded by
goats, Isla Guadalupe is the current focus of conservation efforts by several
organizations. For more see: http://iws.org/CISProceedings/6th_CIS_Proceedings/Oberbauer.pdf
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| Growth form: Guadalupe Island rock daisy (Perityle incana) |
Guadalupe
Island rock daisy is a shrubby perennial or half-woody sub-shrub. It grows to 2-3 ft. (< 1 m) tall and 3-5
ft wide, making it an excellent size for the garden. Mature plants are
irregularly mounded in shape (see above).
The plant is adaptable, filling in around other shrubs.
Like
another island endemic, the Catalina Silverlace (Constancea (Eriophyllum) nevinii from California’s Santa Catalina
Island), Perityle incana is probably
best known for its light colored foliage.
While Catalina Silverlace is truly white, Perityle incana is more often a silvery green in the garden
setting.
The
two species share several other characteristics, making them confusing to the
beginning gardener. They both have a
mounded shape (though the Silverlace is more spreading) and have superficially
similar leaves. As shown in the photo
below, Perityle incana is best described as ‘feathery’ (deeply incised),
while Constancea foliage is truly ‘fern-like’
or ‘lacy’ (bipinnately divided). Once
you see the two together, the differences become more apparent.
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| Foliage of Perityle incana (left) and Catalina Silverlace (Constancea/Eriophyllum nevinii) (right) |
The
flowers of Guadalupe Island rock daisy brighten any garden. Blooming off and on throughout the year, the
main bloom season is spring-summer. We’ve
seen blooms as early as April and as late as the end of July in Mother Nature’s
Backyard. The flowers are clustered in
sunflower ‘heads’ that lack conspicuous ray flowers (the ‘petals’ of sunflower
heads). In fact, the flower heads are
similar to the male Mulefat (Baccharis
salicifolia), but a bright golden yellow.
The flowering heads occur in clusters above the foliage – very decorative
indeed!
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| Flowers: Guadalupe Island rock daisy (Perityle incana) |
Guadalupe
Island rock daisy tolerates full sun along the coast. But give it some afternoon shade further
inland – it’s adapted to slightly cooler temperatures. It naturally grows in well-drained
rocky/sandy soils, but will tolerate clay-loams or even clay with judicious
watering.
Along
the immediate coast, Perityle incana
may get by with no summer irrigation. But remember that its native climate is
more humid than the S. California mainland. In most areas it will need occasional summer
water. In Mother Nature’s Backyard
(summer temperatures in the 80’s and 90’s F.; clay soil) we treat it as Water
Zone 1-2, watering every 4-6 weeks in summer.
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| Frost damage to Perityle incana. Note new growth after ~ 5 weeks. |
In
local gardens, Perityle incana is
sometimes exposed to moderately low temperatures. The species is frost-tender, affected by
temperatures in the mid- to low 30’s F.; this is not a plant for areas with regular winter frosts. If frost is predicted, you can water the day
before and/or cover the plant with an old sheet to protect it. If frost damage occurs, resist the urge to
prune immediately. For more on frost damage see: http://mother-natures-backyard.blogspot.com/2013/02/frost-damage-dont-prune-yet.html.
Other
than the frost sensitively, Guadalupe Island rock daisy is easy to garden with. It’s best neglected except for removing
unsightly spent flower stalks (after the birds have eaten the seeds) and
pruning back by 1/3 in the fall to keep it youthful and shapely. Given
the right sun and water conditions this is a dependable garden plant that
blooms like clockwork in spring.
Use
Perityle incana where its light
foliage contrasts with other shrubs; it’s a great substitute for the non-native
‘Dusty Miller’ (Senecio cineraria). Guadalupe
Island rock daisy is often grown with native sages (Salvia species) and buckwheats (Eriogonum
species) which have similar cultural requirements; it is particularly lovely
with the Red Buckwheat (for more see: http://mother-natures-backyard.blogspot.com/2012/07/plant-of-month-july-red-buckwheat.html).
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| Perityle incana (yellow flowers) with Red buckwheat (Eriogonum grade var. rubescens) in Mother Nature's Backyard |
Guadalupe
Island rock daisy would also look nice paired with evergreen Toyon,
Lemonadeberry, Ceanothus species,
manzanitas and other water-wise green shrubs.
Its yellow flowers work well with many color schemes: yellow-blue; warm
colors (red, oranges, yellows); pastels. We grow annual spring wildflowers around it to
provide off-season color.
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| Guadalupe Island rock daisy (Perityle incana): mature plant |
Some
gardeners grow Perityle incana in a
rock garden or dry stone wall – or at least next to a decorative garden
boulder. This is similar to conditions in
the wild. It is recommended for dry
slopes. The plants also do fine in large pots/containers. In fact, gardeners in colder climates have
been known to bring containerized plants indoors during cold periods.
Another
good reason to plant Perityle incana
is for its habitat value. Many
pollinators, including butterflies and hummingbirds, visit this plant for
pollen and nectar. In the fall, songbirds eat the seeds. So you get a long season of wildlife
viewing. If you enjoy watching/photographing wildlife
you’ll want to place this plant in a convenient viewing location. Your summer
vegetable garden will also benefit from the additional pollinators.
In
summary, Perityle incana is a lovely
and interesting plant that almost disappeared in the wilds. Its light foliage adds interest to the
garden; and the yellow flowers provide welcome color from spring into
summer. We hope you’ll consider adding
this plant to your water-wise – and life-friendly – S. California garden.
For
a gardening information sheet see: http://www.slideshare.net/cvadheim/gardening-sheet-perityle-incana
For plant
information sheets on other native plants see: http://nativeplantscsudh.blogspot.com/p/gallery-of-native-plants_17.html
We
welcome your comments (below). You can
also send your questions to: mothernaturesbackyard10@gmail.com
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