Each
year the National Garden Bureau (NGB) selects
one flower and one vegetable to be showcased.
In 2012, they added a perennial to these selections.
These crops are chosen because they are popular,
easy-to-grow, widely adaptable, genetically diverse,
and versatile. For the first ever perennial of
the year, the NGB chose Heuchera.
Heucheras are all-American. Literally. Different species hail from the islands off the California coast to the highest mountains in the Rockies to the Gulf of Mexico. With this diverse range of habitat, these plants are able to find a niche in everyone's garden. Breeders in America and Europe have taken a well-aimed swipe of a paintbrush between these species, and have assembled a plethora of plants with amazing flower and foliage forms that didn't exist a scant ten years ago. Not only are these plants aesthetically pleasing, but they have become stronger, fuller, and more disease resistant. With few pests, great adaptability to containers and a seemingly unending number of forms, heuchera should be in everyone's garden!
History and Nomenclature
Can
you say Johann Heinrich von Heucher? He was
an Austrian professor of medicine and botany
and a friend of Linnaeus, the father of taxonomy.
Linnaeus would often name plants in honor of
his friends and in 1738 he did so with von Heucher.
Being Austrian, his name was pronounced "Hoyker,"
and, you guessed it, the plant should be pronounced
"Hoy-ker-uh." Botanical illustrations
have shown the plant in different European collections
of American plants which date back to 1601.
Aside from the common name of coral bells, it was also called alum root due to its medicinal qualities. Native Americans used them to stop wounds from bleeding. The stems can be used in a pinch if you cut yourself in the garden.
The first American seed catalog was produced by a man known as Bernard M'Mahon in 1804. Heuchera americana, an east-coast native, was offered in this catalog.
While utilitarian and useful in shady spots, heuchera did not stir the senses as they do now. The Victorian era was a boom period for many genera, but alas, these plants didn't have the wow power to grab the color loving masses. Some Mexican collections including the "real" coral bells, Heuchera sanguinea, made it to Europe in the mid 1800s, and presented a new floral spectrum for breeding.
It
wasn't until 1980 when Brian Halliwell released
Heuchera villosa 'Palace Purple' that these
plants were accepted as foliage plants. At about
the same time, Dale Hendricks of Northcreek
Nurseries released a strain of Heuchera
americana called 'Dale's Strain'. These
two plants were hybridized to form the first
foliage varieties, and the rest, they say, is
history.
Classification and Varieties
There are nearly 50 species of heuchera inhabiting woodlands, prairies, and mountainous regions. Further south, Heuchera sanguinea, can be seen growing amidst cactus in Chihuahua, Mexico. The culture of these indigenous species must meet some of the same cultural requirements of their growing areas. By hybridizing, the ensuing plants carry the combination of traits and the end user gets the best of both worlds.
These
plants are in the Saxifrage family (Saxifragaceae)
which includes Bergenia, Tiarella, Saxifraga
(of rock gardens), Mukdenia and
the giant-leaved Rodgersia. Tiarella,
the foamflower of Eastern and western woodlands,
is so genetically close to heuchera that it
can cross with it, giving rise to the intergeneric
hybrid called Heucherella. By taking heuchera,
with its myriad forms and colors and crossing
it to Tiarella, with a palette defined
by leaf-shape, growth habit and dark-centers,
a vast array of new hybrids have resulted. Some
of the heuchera seen today can involve 5 separate
species (and a hundred cultivars) and the Tiarella
can carry the blood of 3 different species.
Any math student understanding permutations
will flip to the possibilities these crosses
can present.
The
flowers are relatively dainty on most varieties
of heuchera with a color range of whites, pinks
and reds. There are a few species cultivars
which have a very pale yellow tone. Foliage
can vary widely from the ½" wide
leaves of Heuchera pulchella to the
11" wide leaves of Heuchera villosa.
Foliage colors of the species run from greens
to olives to purple veins which are prominent
in winter. Terra Nova Nurseries was at the forefront
of the colored foliage boom with the selection
of Heuchera 'Amber Waves' in 2000. In 12 years,
this company has released an eye-crossing number
of amazing cultivars with foliage in the palette
of metallic rose, yellow, orange, red, velvety
purple and black. Other breeders like Thierry
Delabroye of France have produced a number of
large leaved varieties, like 'Brownies' and
the Big Top Series that are distributed by Ball
Horticultural Company. Foliage can be matte
or glossy, hairy or smooth, and can have contrasting
veins which change color with the seasons. Early
cultivars used to dictate, "If you want
foliage you get lousy flowers, if you want great
flowers, you get plain green leaves." With
today's breeding, you get both on plants like
'Rave On,' 'Swirling Fantasy,' 'Harvest Lemon
Chiffon' and 'Shanghai.' There is another class
of ever bloomers like 'Milan' and 'Paris' which
will both bloom until frost.
In the garden, different varieties fill different niches. Charles Oliver's 'Petite Pearl Fairy' is a mass of color, perfect for the rock garden. Thierry Delabroye's H. villosa hybrids like 'Beaujolais' work well in shady woodland settings. Most heuchera work well in borders and especially in containers. Here they are especially useful as they don't bully other plants and thrive on neglect while adding a perfect foil for other flowers (as well as having a wide range of foliage colors)! Other varieties like 'Berry Smoothie', 'Caramel' and 'Stormy Seas' are tolerant of a large range of conditions and fit into a "landscape" class of plants. Some plants like 'Coral Forest' and 'Marvelous Marble' fit into this class and are offered as seed strains from Syngenta. Ball offers the 'Melting Fire' strain with ruffled, dark brown leaves.
Before
the new wave of hybrid heuchera, many coral
bells claimed a heritage that included only
one species, H. sanguinea, the coral
bells of your grandmother. Today, however, in
order to give gardeners stronger, prettier plants,
breeders are combining species so the newest
coral bells provide a mix of outstanding characteristics.
The common species used in today's hybrids are
H. sanguinea, H. americana, H. micrantha,
H. villosa, and H cylindrica.
'Chocolate Ruffles', for example is hybrid between
H. micrantha and H. americana and
'Velvet Night' is a hybrid between H. micrantha
and H. americana. One of the most
striking varieties, 'Electra,' was a mix of
three species: americana, micrantha, and villosa.
There are a number of straight species selections
from seed like the 'Palace Purple' strain.
Though plant labels often do not list the
Latin name (or the entire heritage), you can
easily search online or talk to a knowledgeable
nursery grower if you have a specific species
you want. Here's a brief primer on heuchera
species and their advantages.
- Heuchera americana likes woodland situations best, survives extreme hot and cold temperatures, offers an exceptionally tidy mounding habit and shows off the most exciting leaf patterns. 'Green Spice' and 'Marvelous Marble' strain from Syngenta are examples.
- H. villosa varieties, with their hairy, large leaves, are best for the deep South and any other hot, humid climate. H. villosa hybrids are especially popular. 'Caramel' is a newer selection with gorgeous apricot leaves in spring that turn amber in summer and reddish in fall. 'Citronelle' and 'Electric Lime' display foliage that's stunning chartreuse. 'Southern Comfort,' the Big Top Series and 'Georgia Peach' have strong H. villosa heritage as well.
- H. micrantha, a native to the West Coast, tolerates wet roots better than other coral bell varieties. These lend their wavy leaves to any hybrid, ruffled form on the market today.
- H. cylindrica presents a more compact form with strong, rigid flower stems that stand up to windy conditions. These are very attractive to bees and butterflies. This species is not as eye-catching as its more showy sister species due to its green or white blooms. Try 'Greenfinch' for its fresh green flowers on short panicles.
-
H.
sanguinea, a Southwestern native, maintains
its often-bright blooms through extreme drought
and heat. Most do well in shady rock gardens
or along woodland paths. Look to bold varieties
such as 'Snow Angel' with mottled green and
cream leaves or 'Firefly' strain or the 'Coral
Forest' strain with profuse scarlet blossoms.
Color your Garden by Number
The following list will assist you in selecting plants in specific color schemes. Landscape designers can use this list to select plants suitable for their region and for "sub" lists when certain cultivars are not available.
| Amber-Peach 'Georgia Peach' |
Black 'Black Beauty' |
Brown 'Cherries Jubilee' |
Gold 'Amber Waves' |
| Green 'Apple Crisp' |
Lime-Yellow 'Citronelle' |
Orange 'Delta Dawn' |
Purples 'Amethyst Myst' |
| Red 'Autumn Leaves' |
Seasonally Multicolored 'Cajun Fire' |
Silver 'Amethyst Myst' |
Silver with Green Veins 'Color Dream' |
| Variegated 'Midnight Rose' |
Culture and Garden Preferences
Heuchera
require well-drained soil. If you've had problems
with coral bells in the past, most likely you've
tried to plant them in soil that's too wet or
full of clay. To solve that, plant your heucheras
in raised beds, on a berm, or in containers.
Even mounding the soil slightly where you plant
them will help. A premium organic planting compost
will provide excellent drainage with enough
moisture.
Other than keeping the soil well-drained and mulched, coral bells have very few other maintenance needs. Let them dry between watering, refrain from using excess fertilizer, and give them neutral or slightly acidic soil (the perfect ph is 5.8 to 6.3, but most aren't too fussy).
Many coral bells do well in part sun, but stay away from hot afternoon rays—foliage will often fade, wilt, or scorch under intense sunlight. Instead, provide shade during the hottest times of the day, or plant where your heuchera will get consistent full or filtered shade.
Heuchera are remarkable for needing little care. When flowers fade, they can be spun off with a flick of the wrist. If stems get too long they can be cut off with the resulting stub resprouting and the piece in your hand replanted to form a new plant. This helps keep your heuchera compact.
When
using "heuchs" in the landscape, they
are best triangulated with most varieties planted
24 inches on center. You will have to look at
the spread on the label to determine the best
spacing. Three words are essential: drainage,
drainage, drainage. Most varieties are drought-tolerant
as well.
Note that as coral bells grow, their crowns rise up and out of the soil slightly. Either mulch to protect the crown, or lift, divide and replant. It's best to divide them every two to three years, with the spring being the best time to do this work.
If necessary, cut back winter-damaged foliage in early spring to make way for new growth. And if you live in a cold climate (Z4), mulch your coral bells in winter, leaving the crowns unburied. Oak leaves are ideal.
Propagation
While most heuchera are initially propagated by tissue-culture, they can be divided by a sharp shovel in early spring when the soil has thawed. A two-year-old plant can easily be divided into 6 plants. Place the divisions buried to the crown in enriched soil and water in. Foliage may have to be removed if any wilting is observed.
Starting from Seed
Coral bells can be bought in seed packets.
These are usually H. sanguinea types and are
fairly true from seed. Fancy-leaved "heuchs"
are grown from tissue culture and are all wide-ranging
hybrids, so seedlings of these plants would
be variable and inferior to the parent. 
Heuchera
have very fine seed and must be sown on top
of the medium to germinate. Thoroughly moisten
sterile seed-starting mix and then fill your
seed tray to the top. Soil can be gently tamped.
Seed must be sowed sparingly. Otherwise the
mat of dense seedlings will be nearly impossible
to pull apart. Germination usually begins after
8 to 14 days in soil that is at a temperature
of 70º-72ºF.
Once the tiny plants have 3-4 true leaves, they can be transplanted to cell packs or a soil flat to grow on. When plants are 3" across, they can be transferred to pots or the garden and watered gently. If they are being moved into full sun, it must be done gradually over a week's time or they will burn badly.
Pests
"Heuchs" have relatively few pests but they do have one nemesis: strawberry or black vine weevil. If you have had plants whose tops "fall off" in the spring, they are being eaten underground by these little monsters. These are creamy-white c-shaped grubs. You must fight with a twofold attack; the brown or black adults are out in late May to early June (watch for munched leaves) and can be sprayed with Bonide Systemic Insect Control. DO spray at night as that's when they come to play (and eat). In fall, beneficial nematodes like NemaGlobe can be sprayed over the soil around the plants. Remember to water before and after the application to get these critters in the soil. Each adult can lay 300 eggs, so control is highly advised. Organic gardeners who experience the tops of plants falling off (from weevil damage) can pour hot water on the ground to kill existing larvae.
Diseases
There are two diseases you might see on heuchera:
mildew and rust. Mildew tends only to attack
varieties of Heuchera sanguinea. Organic controls
such as baking soda in water can provide some
prevention. Mancozeb can be applied as both
a preventative and a remedy. Rust can be a severe
problem if the plants are moist and the temperature
is in the 45º -50ºF range. Plants
will appear dark-spotted from above and when
a leaf is turned over, orange patches are evident.
While rust won't kill a plant, it is quite ugly
and contagious. Preventative measures include
clean, dry facilities (for growers) and copper-based
sprays as used on fruit trees. Mancozeb, Cleary's
or Daconil can also prevent an attack and provide
long-term control. Yellow-leaved heuchera seem
most susceptible. Once a plant has been attacked,
remove the affected leaves and apply one of
the above sprays. Clean equipment with alcoh
ol
after use.
Coral Bells as Cut Flowers or Cut Foliage
Surprisingly,
heuchera leaves also offer extremely long-lasting
foliage for fresh-cut arrangements. Add them
to your floral bouquets by cutting the leaves
so each one has a fairly long stem and then
stick them immediately in water with the flowers
of your choosing. Change the water weekly and
heuchera leaves can live up to two years in
a vase. (They'll even start rooting eventually!)
Try pairing the deep purple leaves of 'Dark Secret', 'Plum Royale' or 'Berry Smoothie' with a spray of yellow coreopsis or a few choice lilies. Marry the chartreuse of 'Lime Marmalade' with blue bachelor's buttons and orange California poppies. Or, arrange the bold orange leaves of 'Peach Flambe' or 'Tara' with green hydrangeas, zinnias or purple salvia. To play up the color silver, combine a silver-toned coral bell like 'Rave On' or 'Silver Scrolls' with white daisies, roses or lilies. Tulip flowers in dusky purples and black work quite nicely with dark leaved "heuchs". European florists are rolling the leaves around roses for a cool effect. We have seen leaves used in wedding bouquets accented with Hypericum berries.
- from the National Garden Bureau. The National Garden Bureau recognizes Dan Heims as the author of this fact sheet. Dan speaks worldwide on his plants and his craft. More information on Dan can be found at Great Garden Speakers: http://www.greatgardenspeakers.com/listing/dan-heims-4c2d59e4091a9.html