Tuesday, August 12, 2014

Plant of the Month (August) : Catalina silverlace – Constancea (Eriophyllum) nevinii

Catalina silverlace (Constancea (Eriophyllum) nevinii; yellow flowers)
Mother Nature's Backyard

Last month we featured one of our loveliest silvery foliage plants – Perityle incana.  This month the whitest of them all, Catalina silverlace (Nevin's Wooly Sunflower), is blooming for the first time.  It simply begged us to be featured as our Plant of the Month.

 Like Perityle incana, Constancea nevinii is a member of the Sunflower family (Asteraceae), one of the largest plant families in California.  It was originally named  Eriophyllum nevinii (in the genus containing other native Wooly Sunflowers) and can still be found by that name at some nurseries.  Studies of plant DNA revealed that Catalina silverlace shares no common ancestor with the other Wooly sunflowers – in fact, it’s a more distant cousin.  In 2000 it was renamed in honor of Lincoln Constance, a well-known plant taxonomist, university administrator and former director of the UC Berkeley Herbarium.  The genus Constancea is monotypic; it contains a single species, Constancea nevinii.   For more about Lincoln Constance see: http://www.calflora.net/botanicalnames/pageCI-CY.html#Constancea

As with other Wooly sunflowers, Constancea nevinii has an extremely limited natural range, being found only on the Southern Channel Islands (San Clemente and Santa Catalina Islands) and the Northern Santa Barbara Island.  The Channel Islands, located just off the coast of central and southern California, are places of great biologic interest.  Like most islands, they contain unique species due to  their separation from mainland populations.  But the Channel Islands have several other unique features. 

Located at the edge of a tectonic plate, the Channel Islands have experienced extensive movement over millions of years, resulting in unique geologic and soil profiles.   As sea levels rose and fell, they were joined and separated from the mainland several times, allowing for species exchange.   Their close proximity has facilitated human visitation/habitation for at least thousands of years, resulting in further exchange of seeds/plants between islands and the mainland.  

The combination of these factors makes the California Channel Islands unique in their flora, fauna and geology; they are currently the subject of great scientific interest.   Unfortunately, many of the endemic species are now extremely rare, often due to human actions like hunting, farming and grazing.  Feral goats have played a particularly destructive role on several islands; their removal has been an important step in preserving native plants.   Interestingly, several island plant species (including Constancea nevinii) are well suited to gardens and are now used extensively in Southern California mainland gardens.

Catalina silverlace, a sub-shrub with woody stem, stands 2-5 ft. tall and at least as wide.  It closely resembles the ‘Dusty Miller’ (Jacobaea maritima/Senecio cineraria), a plant long favored for its white foliage and drought tolerance.  While Jacobaea maritima hails from the western/central Mediterranean region, it shares more than a superficial resemblance with Catalina silverlace.   Both grow in coastal areas, often on rocky coastal bluffs, in areas with a mediterranean climate.   Not surprisingly, both are known for their heat, salt and drought tolerance.   The two plants represent similar solutions to a shared set of environmental conditions.

Foliage of Catalina silverlace (Constancea (Eriophyllum) nevinii)
For comparison with Perityle incana see July, 2014

Catalina silverlace has a mounded, slowly spreading growth habit.  Its long leaves are finely dissected (see above) giving them a delicate fern-like appearance.  The foliage is covered with dense, wooly white hairs, making the foliage appear almost white.   These features help plants survive hot dry summers and are shared with species from other dry climates.  The low, mounded growth habit is often found among plants growing right on the coast.   This form is particularly suited to the wind and salt spray that dominate coastal landscapes.

Catalina silverlace (Constancea (Eriophyllum) nevinii) in bloom

California has native ‘sunflowers’ that bloom from early spring to late fall; Constancea nevinii is a mid-season bloomer.  It may flower anytime from April to August depending on weather conditions.   In our experience, adequate winter moisture is required for a good bloom season. 
Flowers, Catalina silverlace (Constancea (Eriophyllum) nevinii)

The flowers are bright yellow, adding a cheerful note to the summer garden.  On closer inspection, the flowers reveal their sunflower nature.  Flowers have central disk flowers surrounded by a few, very short yellow ray flowers (look like petals).  The individual flowers are small, but the heads are arranged in clusters of 20 to 50 on stalks above the foliage.  The entire effect is showy as seen in the photo above.

Catalina silverlace is a good habitat plant.  Pollinator insects are attracted by the flower’s sweet nectar and pollen.  Expect to see European Honey Bees, native bees, flower flies, butterflies and others visiting the flowers.   Seed-eating birds enjoy the seeds and small animals like lizards will shelter beneath the foliage.

Like the native bluckwheats, Catalina silverlace retains its beauty long after the flowering season has ended.  The flowering stalks, bracts and seeds turn a lovely dark brown that contrasts exquisitely with the white foliage.  In fact, many gardeners consider fall to be the prettiest season for this shrub.  The seeds are dry achenes that spread by wind. 

Catalina silverlace (Constancea (Eriophyllum) nevinii) in fall.

The ‘Island Silver’ cultivar is often available in local native plant nurseries.  A natural variant from Santa Barbara Island, ‘Island Silver’ was introduced by the Santa Barbara Botanic Garden and has grown there since the early 1980’s.   It has very white foliage and all the other characteristics that make this species so attractive.  It does well in local gardens and is a good alternative to the straight species.

Catalina silverlace is fairly undemanding in its requirements.   It prefers full sun along the coast, but is best with a little afternoon shade in hotter inland gardens. It is not frost hardy and can be damaged – even killed – by frost.  If you garden inland where frosts occur be sure to read our discussion last month: http://mother-natures-backyard.blogspot.com/2014/07/plant-of-month-july-guadalupe-island.html

Although preferring a well-drained soil, Constancea nevinii can be grown in clays.  If your soil is dense and compacted, try growing it on a slope or berm.   Once established, it needs very little supplemental water except in dry winters/springs. In Mother Nature’s Backyard we water it once or twice from May to August.     Plants will become leggy if not pruned back regularly in late fall or winter.  For fall pruning, remove spend flowering stalks and prune back the leafy stems, leaving 2-3 sets of new leaves.  This will result in a nice, mounded habit.

Catalina silverlace (Constancea (Eriophyllum) nevinii) against a backdrop of Littleleaf
 Mountain Mahogany.   Native Plant Garden, Madrona Marsh Nature Center, Torrance CA.

Gardeners from wetter climates often envy our native foliage plants – particularly those with very light-colored leaves.  Use Catalina silverlace to best advantage by growing it against an evergreen background of Toyon, Coffeeberry, Lemonadeberry, Sugarbush or Ceanothus (see above).   We also like to highlight spring annuals by growing them against a background of Constancea nevinii.  

The size and shape of Catalina silverlace make it a natural choice as an informal hedge or path border; it also functions well as a low foundation plant or in planters. It is relatively deer-tolerant and is good in fire-prone areas.   Consider planting it with California fuschia (Epilobium canum), Cleveland sage (Salvia clevelandii), native buckwheats (Eriogonum species) and native grasses.   It provides a touch white in a silver garden and is an elegant addition to a habitat garden.     And it is a constant reminder of the special – and rare -  plants native to our coastal islands.

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


Wednesday, August 6, 2014

California Invasive Species Action Week - Aug. 2-9, 2014

Removing English Ivy (Hedera helix) an important invasive species in S. California. 
Gardena Willows Wetland Preserve, Gardena.

This week marks the very first California Invasive Species Action Week (ISAW).  A bit like Earth Day, the Invasive Species Action Week focuses on an environmental problem - invasive species.  And like Earth Day, its purpose is to educate Californians about the problem and inspire us to take individual and collective action.  You can read more about ASAW at: https://www.dfg.ca.gov/invasives/ActionWeek/

What can you do to celebrate Invasive Species Action Week all year long?  Here are a few ideas:

§Volunteer for invasive species removal/restoration projects.   Many local preserves & wild areas have regular restoration days and would appreciate your help.

§Find out which species threaten California. 

§Remove invasive plants from your property.

§Select native or non-invasive plants for your garden.  www.plantright.org  - see also the Native Plant Gallery page on this blog

§Download the ‘Wicked Weeds’ posters and post them where appropriate - http://www.slideshare.net/cvadheim/wicked-weeds-posters-2014

§Use certified “weed-free” hay, seed, mulch, soil and gravel.

§Buy it where you burn it: Don’t spread forest pests by moving campfire wood from one place to another.

§Learn which invaders are in your local area. 

§Eat them. Yes, really.  www.invasivore.org

§Monitor plants and trees for infestation symptoms.

§Share your knowledge

§ Report a Sighting - have you spotted an invader? Tell us where! Visit the Department of Fish and Wildlife’s Invasive Species Program web page (http://www.dfg.ca.gov/invasives/)  to fill out a sighting report!


Thursday, July 31, 2014

Tuesday, July 15, 2014

Western Tiger Swallowtail (Papilio rutulus)

Western tiger Swallowtail (Papilio rutulus) nectaring on Purple Sage (Salvia leucophylla)

Nothing is more enchanting than the appearance of large butterflies in our gardens. July is typically a busy butterfly month, but we’ve been watching the Western Tiger Swallowtails since spring.  If you live in the western United States you may be enjoying them as well.   To learn more about attracting butterflies to your garden see our June 2012 posting (http://mother-natures-backyard.blogspot.com/2012/06/butterfly-gardens.html ).

The Western Tiger Swallowtail ranges through much of western North America from N. Dakota south to New Mexico; west from British Columbia, Canada to Baja California, Mexico. The species is similar to the Eastern Tiger Swallowtail (Papilio glaucus) of eastern N. America and is found mostly between sea level and 5000 ft. (1500 m.).  The tiger swallowtails were formerly included in the genus Pterourus. 

Many westerners recognize this butterfly on sight - it’s large, distinctively colored and relative common. While actually at home in riparian woodlands and stream sides, it’s not unusual to see these butterflies in gardens and city parks.  One thing is certain: you’re more likely to see them in places that have food for their larva (caterpillars): Willows, Cottonwoods, California Sycamore (Platanus racemosa) and ash (Fraxinus spp.).  That’s why we have so many Tiger Swallowtails in Mother Nature’s Backyard.

Two other swallowtail species visit western Los Angeles county gardens (see above).  The Giant Swallowtail is a large black butterfly with a prominent yellow triangle on its open wings.  The Anise Swallowtail, common in some neighborhoods,  looks like a large yellow butterfly wearing a set of heavy black shoulder-pads with 3 short yellow stripes.  The Pale Swallowtail, which has similar markings to the western tiger swallowtail, is black and white (rather than black and yellow) and is rare in gardens.

Western Tiger Swallowtails are large butterflies.  Their wingspan can be as much as 2 ¾ to 4 inches (7 to 10 cm), making them one of the largest butterflies in many western gardens. Females are larger than males, but otherwise similar in appearance.  They are brightly colored, predominantly yellow and black, with spots of blue and red/orange.  The wings are striped like a tiger – four black stripes on yellow - on both the upper and under surface.  The margins of both fore- and hind wings are edged in black with yellow dashes.
Western Tiger Swallowtail (Papilio rutulus)
The hind-wings have ‘tails’ reminiscent of the tail of a swallow – hence the common name ‘Swallowtail’. The lower inner margins of the hind-wings have a dot of blue and orange (some individuals may have additional blue spots, particularly on the underside of wings). The head and body (thorax and abdomen) are striped yellow and black. The antennae are knobbed (not hooked) at the tip. You can get a good look/photo of these butterflies as they sun or nectar, often with their wings spread.      More excellent photos are available  at: http://www.butterfliesandmoths.org/species/Papilio-rutulus and http://nathistoc.bio.uci.edu/lepidopt/papilio/tiger.htm .
While limited to summer in colder climates,  Tiger Swallowtails fly from January through September/October (even all year) in warm S. California sites.  You may note that spring-flying individuals are slightly smaller and paler than their summer counterparts.  But they still are distinctively Tiger Swallowtails.
It’s not uncommon to see males patrolling back and forth through the garden, searching for receptive females.  In the wild, males congregate at shallow pools or damp ground to drink and obtain dissolved minerals. This behavior (termed ‘puddling’) is not often observed in gardens, in large part due to a lack of suitable damp ground.  Males also feed on carrion and dung.  And both male and female adults visit a wide range of flowers to obtain nectar (food). 
Females lay eggs on the leaves of host plants (plants that provide larval food).  The eggs, which are shiny, round and deep green, are laid singly on the undersides of leaves. A female produces approximately 100 eggs in her lifetime.   If you are fortunate, you may witness a female laying eggs.  She curves her abdomen down, releases a sticky egg and deposits it on the leaf. The tiny caterpillar (larva) emerges 4-5 days later.  Ah, the miracle of life!
Tiger Swallowtail larvae go through five life stages (instars) before they pupate (form a chrysalis or cocoon).  They molt between each stage, growing an entirely new exoskeleton to fit the growing, changing caterpillar.  During the early stages, when the larvae are small, they look like a bird dropping – a deterrent to birds and others that might want to eat them.  For pictures of Western Tiger Swallowtail larvae see: http://butterfliesofamerica.com/papilio_rutulus_immatures.htm and http://www.wildutah.us/html/butterflies_moths/papilionidae/h_b_papilio_rutulus_immatures.html
Later stage instars are bright green with a pair of large eyespots, resembling eyes, at the tail end.   This protective coloring also serves to camouflage and fool  predators.  The larvae also possess another potent weapon.  They can raise a brightly colored (and foul smelling) forked organ called the osmeterium (‘stink horn’) from behind the head. The sight and smell of a raised osmeterium are enough to frighten off many potential predators.  
Tiger Swallowtail larvae eat leaves, grow and poop – that’s what caterpillars do!  The larval food plants vary somewhat from place to place but always include willows (Salix species), Cottonwoods and Aspen (Populus species) and Ash (Fraxinus species).  In California, additional native plant sources include the California Sycamore (Platanus racemosa), plants in the Cherry Family (Prunus species), Birches (Betula species) and Alders (Alnus species).  The larvae usually live high in trees and shrubs and are seldom seen by humans.
Western Tiger Swallowtails have 2-3 broods in warm coastal S. California (only one in colder areas).  Summer larvae progress through their development rapidly – sometimes as quickly as 15-20 days from egg to butterfly. Summer broods tend to be the largest.  Late (fall) broods over-winter in the chrysalis in many areas.  As an aid to camouflage, the summer chrysalids are bright green while the fall/winter ones are brown to blend in with surrounding wood.   Butterflies emerge from the winter chrysalids from January through spring, depending on the ambient temperature.
Western Tiger Swallowtail (Papilio rutulus) sunning on Lemonadeberry (Rhus integrifolia)
Watching butterflies in the garden is a fascinating hobby.  It’s inexpensive, you don’t have to travel and you can learn a great deal about the natural world. You may even discover something new about insect behavior!  All you really need are patience and a comfortable place to sit; a camera and binoculars are also useful tools. 
Here are some simple things you can do to make a home for Western Tiger Swallowtails

  1. Plant their favored plants. 

Adult (nectar) plants (relatively simple to provide)

·        California native plants: California buckeye (Aesculus californica); native dogbanes (Apocynum species); native Milkweeds (Asclepias fascicularis; A. eriocarpa; A. speciosa); native Milkvetches (Astragalus species); Cobwebby thistle (Cirsium occidentale); Yerba Santa (Eriodictyon spp.);    Dunn’s Lobelia (Lobelia dunnii  var. serrata); perennial Mints (Monardella lanceolata ; M. linoides; M. macrantha; M.  villosa); Penstemons; Salvias (especially Purple Sage, Salvia leucophylla, in our garden); Wooly blue-curls (Trichostema lanatum)

·        Other garden plants:   abelia, agastache, butterfly bush (Buddleia), lilac, lillies, mints, zinnia

Larval (host) plants (require a little planning)

·       California native plants: cottonwoods, poplars and willows are too big and invasive for most yards.  Try instead native White alder (Alnus rhombifolia), native Prunus species like Hollyleaf & Catalina Island cherries (Prunus ilicifolia), Desert Peach (Prunus andersonii), Desert Almond (Prunus fasciculata), Desert Apricot (Prunus fremontii), native plums and Western chokecherry (Prunus virginiana var. demissa) and California ash (Fraxinus dipetala).

·        Other garden plants: anything in Prunus family (cherries; plums; peaches; nectarines; apricots)

  1. Use pesticides sparingly – or not at all.  Practicing Integrated Pest Management (IPM) is a safer, greener approach to managing garden pests.  Keep plants healthy, use simple preventive measures and use chemical pesticides only as a last resort.   To protect pollinators, never apply pesticides to blooming plants.  For more see: http://www.xerces.org/pesticides/ 
  2. Provide a source of water.  This doesn’t need to be large or sophisticated.  We use glazed clay saucers (like you put under pots) filled with garden soil, gravel and water.  You’ll need to add water daily in warm weather.  If you’re clever, you could probably adapt a hose-fed birdbath dripper to provide water during the day.
  3. Provide sunny, safe places for sunning.  Butterflies need warm, safe places to perch and warm themselves.  Tiger Swallowtails prefer to perch on leaves -  most shrubs with medium to large leaves are fine.  The area should be sunny and out of wind if possible.
  4. Encourage your neighbors to follow butterfly-friendly practices in their yards. 
    Western Tiger Swallowtail (Papilio rutulus) nectaring on Purple Sage (Salvia leucophylla)
We encourage your comments below.   If you have questions about Western Tiger Swallowtail or other gardening topics you can e-mail us at :  mothernaturesbackyard10@gmail.com

Tuesday, July 8, 2014

Plant of the Month (July) : Guadalupe Island rock daisy - Perityle incana

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

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.

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!

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.

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).   

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.

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 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