Plant of the Month (May) : Seaside Alumroot – Heuchera pilosissima

Seaside alumroot (Heuchera pilosissima): Mother Nature's Backyard

Garden shade can be both a joy and a challenge.  Fortunately, Californians are blessed with plenty of charming native perennials that are shade-lovers.  Among the shady favorites are the Heucheras (Alumroots or Coral bells).  A good example, the Seaside alumroot, is blooming right now in Mother Nature’s Backyard.

The genus name, given by none other than Linnaeus, honors Johann Heinrich von Heucher, professor of Medicine and Botany at Wittenberg University.[1]  The scientific name is pronounced several ways: HOY-ker-uh, HEW-ker-uh, or HER-ker-uh. The first pronunciation is probably closest to the original, but all are acceptable. The species name is pie-low-SISS-ih-muh.

The Heucheras are delicate-appearing perennials that are hardier than they appear.  All species in the genus are native to N. America, with thirteen native to California.[2]  Some California Heucheras grow along the coast, while others are endemic to the mountains – often with limited geographic ranges. Only three are native to Los Angeles County: Heuchera abramsii, H. caespitosa and H. rubescens (all mountain species). Fortunately, species from other California regions adapt well to local gardens.  Heuchera pilosissima is native to the coastal forests of Central and Northern California (below 1000 ft. elevation).    

Gardeners around the world are familiar with Heucheras.  They’ve been grown in gardens for many years, and numerous named cultivars are readily available.  Many  cultivars derived from Heuchera americana (native to Central and Eastern N. America) have brightly colored leaves, making them prized accent plants in shade gardens.

 

Seaside alumroot (Heuchera pilosissima): foliage

 

The California natives all have green leaves, though some of the mountain species are very petite in size.  Our natives have flower colors which range from white or cream to medium pink.  The darker pink and red flowers are found on species from the American Southwest and Baja California.  The Southwestern species are sometimes crossed with California natives to produce showy hybrid cultivars.

 

Seaside alumroot (Heuchera pilosissima): plant

Seaside alumroot is medium-size for California species, growing 1-2 ft. (to 0.6 m.) tall and wide.  Plants form an evergreen mound about 1 ft. tall & wide – typical of the Heucheras.  The leaves have a long petiole and are somewhat succulent.  Their shape is rounded and looks a bit like a grape leaf.  The leaf color is bright to medium green; on our plants, the color is slightly mottled.  This species is hairier than some native Heucheras, with the entire plant covered in shaggy white hairs.   In fact, the name pilosissima means ‘hairiest’.



Seaside alumroot (Heuchera pilosissima): flower stalk

 

Like all Heucheras, Seaside alumroot produces small, bell-shaped flowers along vertical flowering stalks.  The entire flowering stalk and flowers are covered with glandular hairs and the flowers are densely clustered about the stalk (more so than in many species).  The many flowers, and their unusual pastel colors, make this a prize Huechera in our estimation. 

The flowers are small (0.25 inch or less) and pink or white colored (ours have a mostly pink floral cup (hypanthium) with white tips to the petals - see photo below).  The sexual parts are exserted (protrude out from the neck of the floral cup).  Heucheras are primarily pollinated by bees.  In our garden, they are visited regularly by hummingbirds, which may also serve as pollinators. 

Seaside alumroot (Heuchera pilosissima): close-up of flowers

 

In general, Heucheras are not self-fertile, so you’ll need several plants if you want seeds.  We raised our Seaside alumroot from seed.  It wasn’t difficult, the only challenge being to keep seedlings moist in our dry climate.  We hope our plants will self-seed and fill in shady areas in our garden.  Heucheras also reproduce vegetatively, producing offsets (new little plants).   If plants become too large for their space (or about every three years) they can be divided.  For details on dividing Heucheras see ref. 3, below.

In S. California, the Alumroots do best in shade – afternoon shade to bright shade under trees for best foliage and flowers.  Seaside alumroot does great on the north side of a wall or building.  It tolerates sandy soils and likes a well-drained soil.  That being said, this species is doing well in our clay loam.  The quoted pH is slightly acidic (pH 5.0-7.0), although ours is a bit more alkali. 

Hailing from the northern coast, Heuchera pilosissima is adapted to more yearly precipitation than it gets in S. California.  We water our plants on the same schedule as our apple tree – a good soak every 2-3 weeks from May through mid-September.  It could probably take weekly water in sandy soils.  The only precaution is to not overwater in hot, humid conditions (which promote soil fungi and root rot).  Southern California gardens are generally so dry and breezy that this is seldom a problem here.

Heucheras are mostly disease-free and easy to manage.  Remove old leaves as needed.  Cut back flowering stalks after collecting seeds.  And divide older plants as needed.  Plants grown in containers need a dose or two of half-strength fertilizer in late-winter or early spring (when plants begin to grow).   That’s really about all.

Seaside alumroot (Heuchera pilosissima): in shady spot
 in garden with Carex pansa, Ribes viburnifolium.

 

We love the look of Heucheras as a ground cover in shady places.  Their small size and neat appearance make them good candidates for lining shady walkways – or growing in containers.  We like to plant them near seating (we love to have hummingbirds come within arms-length).  And Seaside alumroot gives a woodsy look to any shady garden spot.

If you can’t find this species (plant or seed), consider the hybrid cultivar ‘Lillian’s Pink’ (a garden hybrid between Heuchera pilosissima and H. sanguinea).   It’s readily available and has the nice foliage characteristics of Seaside alumroot with the darker pink flowers of the Coralbells (H. sanguinea).   Any way you choose – straight species or cultivar – California’s Heucheras are guaranteed to please!

'Lillian's Pink' alumroot (Heuchera pilosissima X H. sanguinea): Rancho Santa Ana Botanic Garden, Claremont CA.

 

For a gardening information sheet see: https://www.slideshare.net/cvadheim/gardening-sheet-heuchera-pilosissima

For more pictures of this plant see: https://www.slideshare.net/cvadheim/heuchera-pilosissima-web-show

For plant information sheets on other native plants see: http://nativeplantscsudh.blogspot.com/p/gallery-of-native-plants_17.html

 

______________________________

1.       https://www.smgrowers.com/products/plants/plantdisplay.asp?plant_id=837

 

2.       http://www.calflora.org/cgi-bin/specieslist.cgi?where-genus=heuchera

3.       https://www.sfgate.com/homeandgarden/article/Native-Spotlight-The-Delicate-Yet-Rugged-3239236.php

 

 

 

We welcome your comments (below).  You can also send your questions to: mothernaturesbackyard10@gmail.com

 

Plant of the Month (December) : ‘Ray Hartman’ Ceanothus – Ceanothus arboreus x C. griseus ‘Ray Hartman’



'Ray Hartman' Ceanothus - Mother Nature's Backyard, 2017

It’s been an uncommon year throughout the world in 2012.  The ‘La Niña’ climate pattern, with an unusually dry and windy summer/fall, has local plants confused.  Some are blooming earlier than expected.  Among them is the ‘Ray Hartman’ Ceanothus (see above as it looks in 2017).

The genus Ceanothus contains about 50-60 species.  The evergreen species are primarily from California, while the winter-deciduous Ceanothus americanus is native to the eastern U.S. and Canada.  The genus is included in the Buckthorn family (Rhamnaceae) along with California Coffeeberry and the Redberries.   Ceanothus are often known by their genus name - Ceanothus – although another common name is California Lilac.

Several Ceanothus species are native to western Los Angeles County, including the Catalina/Tree Ceanothus (C. arboreus) from Santa Catalina Island.   The Ceanothus of Los Angeles County are members of the chaparral plant community, normally growing at elevations of 1000 ft or greater in the local foothills.   None are native to lower elevations like the Gardena area.

People fall in love with Ceanothus and want to grow them. That’s not surprising - they are beautiful evergreen shrubs.  But choosing a Ceanothus can be a gardening challenge.  Native plants tend to do best under their natural conditions, including light, soil characteristics, precipitation patterns, etc.  Most Ceanothus – whether from the local foothills or the Central/Northern California Coast – grow in conditions quite different from those in Gardena.   We chose ‘Ray Hartman’ because it’s known to be ‘garden hardy’ in our area.  But we need to remain aware that our conditions are not optimal for Ceanothus.   For example, our clay-loam soil drains more slowly than the rocky soil preferred by most Ceanothus. We’ll have to be careful not to overwater.  

   

‘Ray Hartman’ Ceanothus is interesting in several ways.  First, it’s a hybrid (cross) between two parent species: our local Ceanothus arboreus and the northern California Ceanothus griseus (sometimes also called C. thyriflorus var. griseus).   In scientific notation, a hybrid is denoted as follows: Parent species 1 x Parent species 2.   Whenever you see a scientific name with that format, the plant is a cross between two separate species.  A hybrid can occur naturally – bees are notorious for cross-pollinating – or be created artificially, usually by careful hand pollination. 

‘Ray Hartman’ Ceanothus is also interesting because it’s a named cultivar.  A horticultural cultivar is simply a plant variety that’s been selected specifically for gardens.  Cultivars usually have characteristics that make them particularly suited to gardens – nice size, flower color, drought tolerance, etc.   Like hybrids, cultivars can be naturally occurring (in the wild), selected by nurserypersons from plants growing in a garden or created by careful hand pollination.   Some cultivars are hybrids – others are not.  All cultivars are denoted as follows (with the cultivar name in single quotes):  Genus name   species name  ‘Cultivar name’. 

‘Ray Hartman’ Ceanothus (Ceanothus arboreus x C. griseus  ‘Ray Hartman’) is a hybrid cultivar.  You can tell that immediately by its name.   It was released into the nursery trade by Rancho Santa Ana Botanic Garden in 1948.  It’s one of the older California native cultivars and has a long history of use in S. California gardens.    With a bit of luck – and carefully watering – it will succeed in Mother Nature’s Backyard.

 

Hybrid plants may exhibit characteristics of both parent species.  ‘Ray Hartman’ Ceanothus inherits its size and form from its Catalina Ceanothus parent.  ‘Ray Hartman’ has a tree-like form and will grow quite quickly (2-4 ft a year to start)  to a final height of 10-15+ feet and about as wide.   Technically, ‘Ray Hartman’  is a large rounded shrub, but its large size and open, upright growth pattern make it a good candidate for pruning up as a small tree.  That’s what we plan to do with our ‘Ray Hartman’ Ceanothus.

When creating a ‘tree’ from a large shrub it’s important to not only choose the right species but also to select a young plant with a good basic structure.  Ceanothus species range in size from low-growing groundcovers to large shrubs.  So, it’s essential to choose the right Ceanothus for the job.   The basic structure, evident even in a young plant, will determine the future shape of a plant.  It’s important to find a plant with the right basic shape, even if it means searching through a number of one-gallon plants at the nursery.  Time spent in selection will be richly rewarded with a nicely-shaped tree or shrub in the future.

'Ray Hartman' Ceanothus pruned up as small tree.
Mother Nature's Backyard - 5 years after planting

 

Like other chaparral shrubs, Ceanothus take several years to become established. It’s best to leave them alone during the first few years, only pruning out diseased, damaged or crossed branches.  We just pruned out a few crossed branches that would have rubbed and caused bark damage this winter.

Start pruning a fast-growing Ceanothus in the second or third summer after planting, after bloom is finished and the weather is dry. If training a slower-growing type, you may want to wait until the 4^th or 5^th summer.  Start by removing several of the lowest branches.  Trim these off all the way to the main trunk, being careful not to prune into the bark ‘collar’ where the branch connects to the trunk.  When pruning a Ceanothus, never prune a branch greater than 1 inch diameter and never prune out more than ¼ of the branches.    

Over the next several summers continue to select for upright growth by pruning out branches that grow down or out.   Most Ceanothus have pleasing natural shapes;   your goal is to accentuate the natural shape.  After the first few years you’ll mostly be pruning out damaged, diseased or crossed branches.  

Another trick to producing a well-shaped Ceanothus tree or shrub is to tip-prune young branches during periods of active growth.  In nature, deer ‘prune’ the delicate (and tasty) ends of branches in spring/summer.  The plant responds with increased growth of side branches, creating a fuller plant.  Since we’ve no deer in Mother Nature’s Backyard, we’ll have to ‘be the deer’ with our pruners for a while.

 

 

Like its C. griseus parent, ‘Ray Hartman’ Ceanothus has shiny rounded leaves that are large for a Ceanothus (up to 1 inch).  Because it’s evergreen with minimal summer water it looks good year-round.   It’s most often used as a small tree or large shrub, but can also be planted as a large hedge/hedgerow or screen plant. Like most Ceanothus, ‘Ray Hartman’ can be grown in full sun to part-shade.

The medium blue flowers grow in rather long (3-5”) spike-like clusters.  While individual flowers are small, there are hundreds of sweet-scented blooms per cluster. In a good year, ‘Ray Hartman’ will literally be covered in blooms (see below).   Like many Ceanothus, ‘Ray Hartman’ may flower both fall-winter and spring (the main bloom season).

 

‘Ray Hartman’ is among the most garden-tolerant of all Ceanothus cultivars. It adapts to a wide range of soil types from sandy to clay and is a bit more tolerant of summer water than other Ceanothus.  It can take inland summer heat and is very drought tolerant once established (after the first year).  We recommend occasional deep water (or none nearer the coast) once established.  With our clay loam we plan to water ‘Ray Hartman’ deeply once a summer - in August, when summer monsoons often provide water to our local mountains.  

In addition to their other attributes, Ceanothus provide excellent habitat for birds and insects.  All Ceanothus are good for attracting bee and fly pollinators.  Ceanothus species are larval host plants for the beautiful  Ceanothus Silkmoth (Hyalophora euryalus (Boisduval, 1855)) along with manzanita (Arctostaphylos), gooseberry (Ribes), willows (Salix), alder (Alnus), and mountain mahogany (Cercocarpus betuloides).

Ceanothus seed is readily eaten by Mockingbirds, Bushtits and finches.  Larger Ceanothus species also provide important cover and nesting sites for local birds.   Planting a Ceanothus can be an important step to attracting more birds to your garden.  We’ll discuss ‘Ten Natural Ways to Attract Birds’ in our next posting (December, 2012).

 

'Ray Hartman' in Dec. 2012 - 10 months after planting



Our 'Ray Hartman' in December, 2013 (20 months after planting)

'Ray Hartman' in 2015 - 3 years after planting



'Ray Hartman' in 2017 - 5 years after planting
Note that all 5 years were drought years in our garden.



 

'Ray Hartman' in 2018 - 6 years after planting as 1-gallon.

 



 

Comment on your experiences with 'Ray Hartman' Ceanothus below.  Send your gardening questions to us at: mothernaturesbackyard10@gmail.com

 

Best California Native Plants for Wildlife - Post Your Favorites

Those of us who garden with California native plants notice an increase in wildlife visitors almost immediately.  Some plants attract butterflies, others are magnets for native pollinators and still others are filled with birds. 

We're compiling a list of the best California native plants for attracting wildlife to western Los Angeles county gardens.   Since we have less experience with cultivars, we especially need your help in identifying native plant cultivars that are 'wildlife magnets'.  But we're  interested in all recommendations on good California native habitat plants for local gardens.

Please share your experiences by posting a comment to this post.  List the species and cultivar name(s) and note the kinds of wildlife it attracts to your garden.  Feel free to list as many species/cultivars as you wish. 

We will use your feedback to update our list.  The complete list will be posted on this blog later this spring.

Thanks for your help.