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Three year old Lemonadeberry (Rhus integrifolia)
Mother Nature's Backyard garden |
December
is a quiet time in many Southern California gardens. This is just as well,
given the flurry of other activities this time of year. Plants are only beginning to respond to
winter rains and the glory of fall is but a distant memory; it’s truly a quiet
time. However some plants do bloom in the cooler months from December through February. For example, the native Lemonadeberry brightens
a cloudy day with its masses of cheery pink flowers.
Lemonadeberry
(Rhus integrifolia) is a member of
the Anacardiaceae, the Sumac or
Cashew family. Other S. California
natives in this family are the Poison oak (Toxicodendron
diversilobum), the Laurel sumac (Malosma
laurina) and the closely related Sugar bush (Rhus ovata) and Sourberry/Basket bush (Rhus trilobata). The family
includes a number of well-known members including the Cashew, Mango and Smoke
Tree. The non-native Brazilian and Peruvian
Pepper trees, which have so naturalized that many think them S. California natives,
are also members of this family.
Trees
and shrubs in the Anacardiaceae
produce a milky sap which is poisonous – sometimes dangerously so. Fortunately,
shrubs in the genus Rhus, the true
Sumacs, are more of an irritant than a danger to most people. This makes them good candidates for the home
garden, where they can replace truly toxic non-native shrubs like the Oleander.
The
red-fruited true Sumacs (Rhus species)
are now separated from their white-fruited cousins in the genus Toxicodendron (poison oak; poison ivy;
poison sumac). Rhus species do not produce urushiol, the
chemical responsible for the severe allergic reactions caused by poison oak and
poison ivy. While gardeners are advised
to wear gloves and long sleeves when handling Lemonadeberry, the itchy rash
associated with sap exposure is usually mild and short-lived. Rhus fruits are used as spice or flavoring
agent in both the Middle East and North America, where they grow native.
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| Rhus integrifolia, Palos Verdes peninsula, California (foreground) |
Lemonadeberry is a true Southern
California shrub, growing from south of Santa Barbara to Baja California,
Mexico. While primarily a coastal
species, it ranges east to Riverside County, appearing in the Coastal Strand,
Coastal Sage Scrub and Chaparral plant communities. Typically it grows in drier canyons, either on
north-facing slopes or slopes/bluffs facing the ocean. A lowland species, Lemonadeberry is rarely
found above about 2500 ft. (900 m.) elevation, its distribution likely limited
by freezing temperatures.
Lemonadeberry
is a large evergreen shrub, reaching a maximal height of 6-10 ft. in protected
areas and 2-3 ft. along the immediate coast.
It is usually somewhat wider than tall, spreading to as much as 10-12
ft. in diameter in favored spots.
Interestingly, it can be kept to a much smaller size with regular
pruning (more below).
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| Lemonadeberry (Rhus integrifolia): new foliage |
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| Lemonadeberry (Rhus integrifolia): new foliage |
The
leaves of Rhus integrifolia are
simple, usually light- to gray-green (although they may be darker) and rather
thick, fleshy and waxy. The leaves may
have pinkish margins or midribs (the main vein of the leaf) and new leaves/branches
are a shockingly bright pink or orange.
The bright color is due to the production of Anthocyanins – chemicals
that provide a ‘natural sunscreen’ and herbivory deterrent to protect the delicate
new growth. The bright foliage adds a
spot of color this time of year. The
older bark is gray and not particularly showy.
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Students from CSU Dominguez Hills measure Lemonadeberry (Rhus integrifolia)
Palos Verdes peninsula, CA |
Lemonadeberry
shrubs are dense. Their thick trunks are
many-branched, starting quite low to the ground. The new wood is soft – almost rubbery – but mature
wood is dense and can be used for fuel.
The wood is pretty and distinctive in cross section, but we’re not aware
its use in craft or furniture-making. In the wilds, young stems and branch tips
are regularly nibbled by browsing animals, increasing the foliage density. Mature plants in the wild are virtually impenetrable.
Flowering
can occur at any time from December to February or March in S. California. The timing reflects yearly climatic variability,
primarily in temperature and precipitation (plants flower early in warm, dry
years). While small (1/4 inch), the
flowers are showy, even in bud (see below).
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| Flowers & buds: Lemonadeberry (Rhus integrifolia) |
Lemonadeberry
flowers are simple affairs with five pink or sometimes white petals. The flowers are clustered at the ends of branches,
with literally thousands of flowers on a mature shrub. The flowers, indeed the shrub itself, remind
some of the non-native Indian Hawthorn (Rhaphiolepis indica), a common garden shrub in S.
California. In fact, Lemonadeberry is a good
native substitute for Indian Hawthorn.
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| Close-up of Lemonadeberry flowers. Left inset is male flower. |
The flowers have a lightly sweet fragrance and are an
importance source of nectar and pollen for winter-flying bees, their principal
pollinators. Individual plants may
contain only male or only female flowers (dioecious), or a combination of bisexual
(complete) and unisexual flowers (see above). This arrangement likely allows
the species to maximize fertility in different environments. The
male and bisexual flowers have conspicuous anthers with yellow pollen (above). Plants are not self-fertile, so you’ll need
at least two for good fruit production.
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| Fruits of Lemonadeberry (Rhus integrifolia). Inset shows fully ripe fruits. |
The fruits of Rhus
integrifolia are drupes – small, flattened, fleshy fruits with a large seed
or two. The fruits start out a pink-white
color and ripen to red-orange in late spring or summer. Fruits are covered by a crystalline coating (see
above) which has a distinctive tart flavor.
While native Californians sometimes eat the fruits fresh, many of us
prefer to soak the pink fruits in warm or cool water to extract the lemony
flavor. The ‘flavored water’ that
results (after the fruits are strained out) can be sweetened to produce a
lemonade-like beverage.
We assume that Lemonadeberry-flavored water can also be
used to make a distinctive jelly,
dessert gelatin or syrup. We’ll try these
potential uses and report back; if all goes well, we’ll even feature the
recipes in a future blog posting! (http://mother-natures-backyard.blogspot.com/2015/05/california-gourmet-cooking-with.html). In the
Middle East, red Rhus fruits are dried and ground into a spice that’s used on
salads, meats or kebabs for a spicy lemon flavor. We’ll also try this idea out when our fruits
are ready.
In our experience, the fruits don’t create any problems
or mess. If not used by humans, they
will be gobbled up by Northern Mockingbirds, Jays, Flickers, Crows and other fruit-eating
birds. We rarely see fruits on the
ground in our gardens. However, we do
see lots of birds eating, perching – even nesting – in our mature Lemonadeberry
shrubs.
Lemonadeberry is very easy to grow in our area. We’ve had good luck with it in compacted clay
soils and sandy soils. Needing little in
the way of added soil nutrients or amendments, it can take alkali soils (pH 7.8
to at least 8.0 and likely higher). It
does fine in full sun, though it prefers a little afternoon shade in very hot inland
gardens. Its foliage is susceptible to
frost damage; however plants will usually re-sprout unless low temperatures are
severe or prolonged.
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Lemonadeberry (Rhus integrifolia) in a garden.
Garden of Dreams, CSU Dominguez Hills. |
Lemonadeberry is quite drought tolerant once established
(2-3 years). During the past two dry
years we’ve summer-watered some plants every month, while others have received no
supplemental water. Both groups have done just fine. In Mother
Nature’s Backyard, our Lemonadeberry was mulched with chipped wood at planting
time. We let mature plants self-mulch,
supplemented with chopped up trimmings from the plants.
Lemonadeberry is a usefully substitute for non-native evergreen
shrubs commonly used in local gardens.
Its size and density make it a useful background plant. It can
also be trimmed for a water-wise foundation plant. One of
our favorite uses is as a hedge, screen or hedgerow shrub. The dense foliage makes it an ideal ‘backbone
plant’ for a mixed hedgerow; we like it combined with Toyon, Catalina and
Hollyleaf cherries, and local Ceanothus species. It is a great choice for slopes, where its
deep fibrous roots bind the soil, limiting erosion.
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Native plant hedgerow at CSU Dominguez Hills (Heritage Creek Preserve)
Lemonadeberry (Rhus integrifolia) is main shrub. |
If growing Rhus
integrifolia as a hedge or large shrub, realize that some plants are slow
to get started and many experience a gangly adolescent phase. As seen above, shrubs planted as one-gallon
shoots grow to substantial size in six years, even in drought conditions. But plants take time to grow and develop their
mature shape. We suggest letting Lemonadeberry grow
naturally (without much pruning) for the first 2-3 years. Once a plant begins to develop long side
branches then it’s time to begin pruning.
Even if you want a more natural shape, you’ll want to do
some yearly pruning, at least in the beginning.
In the wilds, young plants are regularly ‘pruned’ by rabbits, deer and
other animals. That’s why wild plants often
have a nice rounded shape! In your
garden, you’ll have to ‘be the deer’, cutting back unruly branches in late
spring/summer. In fact, you can prune anytime
the plant is actively growing. But you’ll
sacrifice some flowers and fruits if you prune in fall.
How much pruning is needed? That’s entirely up to you. Some gardeners prefer a natural look – they
prune only for safety or plant health.
At the other extreme, we’ve seen plants formally hedged to four feet
tall. A formal hedge will need regular (even
monthly) hedge pruning to keep it neat and tidy. The formally hedged plant will have fewer flowers and fruits; but
no one will guess it’s a native plant and it will be very water-efficient!
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Mixed hedgerow with Lemonadeberry, Toyon and native cherries.
Heritage Creek Preserve, CSU Dominguez Hills. |
You can actually have the best of both worlds. If a formally clipped hedge is needed (to face
the neighbors), prune one side formally and the other (facing your garden)
semi-formally. This will often please
all parties. You needn’t be too worried
about how to prune a Lemonadeberry – it’s a very forgiving plant.
We hope you’ll want to consider Lemonadeberry for your garden. In addition to being pretty and evergreen, its
adaptive ways and useful attributes make it a garden winner. We already pointed out its culinary and
habitat values. In addition, Rhus
integrifolia leaves and smaller branches (e.g., prunings) can be used to
dye natural cloth or yarn a nice tan color; they can also be used as a mordant
to help bind other natural dyes.
Native Californians have several additional uses for
Lemonadeberry. Tea from the leaves is
used in treating coughs and a drink made from ground seeds for fever. The ground seed is also used with the fruits
for tea; tea from the bark was used after childbirth. The wood has been used as fuel. And the seeds produce an oil which can be
extracted and used for making candles.
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Large lemonadeberry (Rhus integrifolia).
Rancho Santa Ana Botanic Garden, Claremont CA |
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| Lemonadeberry in MNBY - 2016 (four years old) |
