Plant of the Month (April) : Meadow onion – Allium unifolium ~ Tk-123456

Meadow onion (Allium unifolium): about to bloom

Mother Nature's Backyard

It’s
April and California native bulbs are beginning to bloom in local gardens. The Meadow onions in Mother Nature’s Backyard
have flower buds – about ready to burst into bloom. So we feature this lovely true bulb as our
Plant of the Month. The scientific name
is pronounced: AL-ee-um yu-nee-FOE-lee-um.

The
Meadow onion is not native to Los Angeles County. It grows along the Central and Northern coast
of California, from San Luis Obispo County into Oregon. It grows in moist, often grassy areas on
coastal cliffs in the coastal pine and mixed evergreen forests. It likes moist soils and is most comfortable
in clay. These two preferences make it a
good choice for many gardens.

Meadow onion (Allium unifolium): bulb

Allium unifolium is an onion (genus Allium), a cousin to our culinary onions
and garlic. The onions were formerly
included in a large bulb-forming family, the Lilliaceae. Some taxonomists
now recommend placing the onions in their own family, the Alliaceae. Others place the onions in the Amaryllis Family (Amaryllidaceae), along with such garden
genera as Agapanthus, Amaryllis, Clivia, Narcissis and Zephyranthes. Only
time will tell where the Alliums will end up.

California
has over 45 different species of native onions.
The vast majority grow in Northern California or the Sierra Nevada
Range. Only 11 are native to Los
Angeles County, and only four (Allium
dichlamydium, A. haematochiton, A. peninsulare and A. praecox) are to western Los Angeles County or the Southern
Channel Islands. Fortunately for S.
California gardeners, even the northern species can often succeed in local
gardens – if only you can find a source for the bulbs!

Meadow onion (Allium unifolium): foliage

Like
most Alliums, Meadow onion is a fairly
simple perennial. Its leaves emerge from
the bulb with the winter rains. We often
see them start to emerge in February in our garden. The leaves are the simple, strap-like leaves
of the onions. The genus name unifolium mean ‘single-leaf’; in fact, another
name for this plant is the One-leaf onion.
As seen above, plants are indeed sparsely leaved (one to four leaves is
typical).

Meadow onion (Allium unifolium): flower bud

The
leaves often start to wither from the tips (and sometimes wither altogether)
before the flowers emerge. Meadow onion
blooms in spring or early summer: usually April or May locally, but a bit later
in colder climates. The flowers grow in
dense clusters (umbels) on 1-2 foot (30-45 cm) flowering stalks. If you live in
a dry place like S. California, the flowering stalks may be a little shorter. The buds are tightly packed in a membranous
sheath (see above) at the tip of the growing flower stalk. The stalks grow very quickly to their full
height.

Meadow onion (Allium unifolium): flowers

Meadow
onion has the star- or bell-shaped flowers typical of the onions. The six veined ‘petals’ are actually tepals
(petals and sepals look alike). The
flowers are individually small (about ½ an inch across), but with 15 or more
flowers per umbel, this onion is a showy bloomer. The flower color is most often a pale
lavender or pale pink, though white-flowering forms are known.

Meadow onion (Allium unifolium): flower, lebelled

The
flowers contain both male and female parts (‘perfect’ flowers). The pollen in this species is either gray or
yellow. The plants produce seeds in our
garden, so they do attract some insect pollinators with their mildly sweet
aroma. While the literature specifies
bees as pollinators, we more often see the flower flies (below).

Meadow onion (Allium unifolium): pollinator

(Syrphid (Flower) fly.

Allium unifolium is easy to grow. It can be grown in just about any soil,
although it prefers the moisture-retaining clays. It needs a neutral to alkali soil (pH
7.0-9.0). While it grows in full sun up north, Southern California gardeners
should plant this species in part shade (afternoon shade to fairly shady). This plant does need good winter/early spring
rains. We had to supplement ours this
dry winter. Unlike some native bulbs,
this species can take occasional summer water.

We
let our plants go to seed, then let them self-seed naturally (or spread them
where we want to start a new patch). Patches increase both by seed and by offsets
(new little bulbs). A modest investment
in bulbs will increase to a nice grouping within 4-5 years. We like to start out by planting 8-10 bulbs
within a 2 square foot area. Don’t
worry about critters digging up the bulbs – they tend to leave onions alone.

Meadow onion (Allium unifolium)

We
love the flowers of this onion. The
color contrasts nicely with native grasses and wildflowers. It’s great for brightening shady areas of the
garden, for example, under trees. The
plants naturalize nicely, and can help ‘tie together’ parts of the garden with
their pastel leaves and flowers.

Bulbs
are a perfect choice for bordering pathways, as an accent plant in a rock
garden or along a garden wall. Meadow onion’s flowers have a light, sweet fragrance,
making them a good choice for containers near seating areas and as cut flowers.
This bulb would do well around the drier
edges of a vegetable garden or in an herb garden. There is some debate about whether this
species is edible. Native Californians
did not eat it; however, at least one blogger uses the stems as a flavoring
agent [ref. 1, below].

Meadow onion (Allium unifolium): in garden

So
why include Meadow onion in your garden?
First, it’s easy to grow and available from bulb dealers. Second, it’s a little charmer that’s adaptable
to garden challenges like clay soil and a bit of shade. Thirdly, it provides an economical solution
to providing masses of spring color – or to naturalize.

And
finally, Meadow onion has all the magic of a native perennial bulb. It gives you something to look forward to,
without much care, year after year. It’s
a seasonal treat, anticipated and enjoyed, that ties us to the land and its seasons. We echo many previous garden mavens, in
singing the praises of garden bulbs.