Since I have been focusing on buying more native perennials
from local sources I have scaled back on the number of plants I am starting
from seed. I felt a little guilty about
not starting any seeds, then remembered, what about native annuals. There are quite a few annuals in the nursery
trade with native parentage, but in general
finding seed for wild-type annuals can be a challenge.
Most of the native-derived annuals are from the southern
parts of North America, particularly the tropical regions. The past few years I have mostly been using
annuals with North American origins in pots on our deck.
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Other than the Ivy Geraniums all these annuals have North American heritage: Lantana camera, Melanopodium divaricatum, Zinnia 'Profusion' series, Salvia farinacea. |
Last year I planted out some native annuals that are also
found naturally in the Mid-Atlandtic region, Partridge Pea (
Chamaecrista fasciculata) and American
Pennyroyal (
Hedeoma pulegiodes) as
well as some short lived perennials
Rudbeckia
hirta and
Monarda punctata which I started from seed. I will be watching to see if these will
reseed successfully. What I like about
the indigenous annuals is that if they find suitable conditions, they will
reseed and fill in gaps in the garden and add spontaneity to the landscape that
is lacking with plants that only spread vegetatively.
My first choice is to plant regionally native annuals and
biennials. If suited to the site, these
plants will naturally spread to fill open gaps between shrubs and
perennials. My second choice is to use
visually appealing annuals from tropical North America like Zinnias and Cosmos,
that have a low risk of spreading out of control. Some of these may reseed in protected
locations, but they are unlikely to escape into the wild. I avoid using North American annuals from
other regions (or any plants for that matter) with a high risk of spreading. You can identify many of those on the USDA
Plants database by checking under the
'Legal Status' tab for a given
plant. An example is that California
Poppy (
Eschscholzia californica ) is listed as an invasive
weed in Tennessee. You can also check the
Invasive Plant Atlas.
I've sorted my North American annuals for this year into two
groups, those native to or naturalized in Maryland and those not found growing
naturally in Maryland.
Native annuals found in Maryland
Plains Coreopsis,
Coreopsis
tinctoria, is
originally from the centrals plains but has escaped and is now found growing across
most of the US. It tolerates a range of
soil conditions in full to part sunlight.
It is a good nectar source and is reportedly deer resistant! The long blooming season (June-Sept.) of golden flowers with red centers makes
it a good filler plant. I have not grown
this species before, but from what I've read it looks to be easy to grow.
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This Beach Sunflower grew to about 4 ft in a pot. |
Beach Sunflower,
Helianthus
debilis 'Pan' is native to coastal
areas from Texas to North Carolina but has spread as far north as New
England. It would not be found growing
naturally in mountainous part of Maryland where I am located. This annual sunflower differs from
the Common Sunflower (
H. annuus) in
that it is highly branched and, although the stems are long, at 5-7 feet, it
tends bend over and weave into neighboring plants. The branches are usually mottled with purple
or white. The flower is of the typical
sunflower form, though smaller, measuring 2-4 inches across and blooming is
from July into October. It likes full
sun and well drained soils. As expected
for the beach, this plant will tolerate salty soils. It performed nicely for me in pots up
in Boston. This species likes warmer
soil for germination which is more easily achieved in planter pots or a raised
bed.
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These Sulfur Cosmos are competing for space with some culinary mint. |
Sulfur Cosmos,
Cosmos sulphureus is native to Northern and
Central
Mexico where it is found in open areas along roads and rivers, in
forest openings and pastures. It has
escaped cultivation in the
United States
and populations have been found from
Texas to
New York and
Connecticut
and in
California. This species is listed in as a
pest plant in Tennessee and Florida. In my experience in Boston, this species will
reseed itself for a couple of years, then fade out unless some new plants are
brought in. What I like about this
Cosmos is that it comes into bloom very early in the summer and that it does
not flop over as bad as Garden Cosmos,
C.
bipinnatus.
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After blooming the flowers of this Sneezeweed turn white and disappear into the foliage. These did reseed into the pot the following year. |
Sneezeweed,
Helenium
amarum 'Dakota Gold' grows to about a foot in height and is covered with
self-cleaning yellow flowers from early summer to frost. It is originally a native of the Ozarks but
has spread throughout the southeast and as far to the northeast as
Massachusetts. It tolerates dry soils
and is also resistant to deer. When I
tried these a few years ago I had excellent germination without any
pretreatment of the seed. The small
size and intensity of bloom make this a good candidate for the front edge of a
border.
The native ranges of these next two plants actually include the Mid-Atlantic region.
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Adlumia blooms from late June to frost. The shiny black seeds are easily collected by shaking the dried flowers on the vine. |
Allegheny Vine,
Adlumia
fungosa is a biennial vine, native
to mountain woods of the American East. I
have
blogged about this plant in the past.
It's one of my favorites. This is
a true biennial, the first year is spent as a tight rosette of finely divided
leaves. The second year the vine climbs
about 10 feet and it blooms with pale pink dangling heart-shaped flowers. The vine is rather delicate so it needs
support and not too much sun. I have
lost some due to the wind causing the plant to twist. In its native state it often climbs over
rocks, rather than scaling trees.
Miami Mist,
Phacelia purshii, is a winter annual that is native to Mid-Atlantic states and lower Mid-West. It has small, fringed lavender-colored flowers that bloom in spring. As a winter annual, it needs to get its start in the fall, as temperatures cool and moisture increases. From what I have read, the seed should be exposed to warm summer temperatures to break the seed dormancy. So I will direct sow some of these in June and also put some outside in small pots where I can keep an eye on them. They overwinter as a rosette of leaves, then put forth a flowering stalk the following spring.
North American Annuals Not Hardy in Maryland
These last three plants have not been found growing in the
wild in Maryland.
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These Bluebonnets were growing at the Lady Bird Johnson Wildflower Center in Austin, Texas. I doubt I will have such good results in Maryland, but I'll try. |
Texas Bluebonnet,
Lupinus
texensis is a Texas native and my
wife's favorite flower. I have tried
these once before with limited success.
This is due at least in part to the very different growing conditions in
the Northeast. Besides soil composition,
it takes much longer for the northern soils to warm up relative to Texas. On doing a little more reading, I found that
it is helpful to inoculate the seeds with the correct bacteria to help with nitrogen
fixation. I found that
Prairie Moon Nursery offers a variety of inoculum for different legumes in
small packets at a reasonable price.
Also, the Bluebonnets are winter annuals, like the
Phacelia above. I will plant
some seeds this spring, like regular annuals and I will hold some back for fall
planting. My concern is that our winters
may be a bit too cold for them to survive. Anyway, we have a
little garden for Texas plants (south-facing, drier soils) and we'll see what
happens.
Spanish Flag,
Ipomoea lobata, is an annual vine from Mexico that grows to 5-10 feet. I found no records that show it to be self-sustaining in the contiguous US. It produces racemes of tubular flowers in mid-to-late summer that change from red to orange and then white as they mature. These flowers are favored by hummingbirds. I've seen this vine used to quickly cover a chain-link fence. When starting from seed, scarification and presoaking in warm water is recommended.
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Texas Sage blooms from late July to frost. |
Texas or Hummingbird Sage, Salvia coccinea, is native to the southern states. But I've had it reseed in Boston for several years in protected locations. I've grown it successfully in both pots and in a raised bed. I like the taller more open form of this red Salvia compared to the heavier dense blooms found on the commonly available annual Scarlet Sage, S. splendens.
As I recall, bumble bees would get nectar by landing on the top of the flower and sticking their tongues into the calyx tube at the base of the flower. It will be interesting to see how our hummingbirds approach this flower.