Native Annuals Wrap Up for 2014

For the past 6 or 7 years I have been interested in using native annuals in my landscapes.  By working with species that are adapted to local climate and growing conditions they can behave essentially as highly mobile perennials, moving around the garden by reseeding to find their optimal spots.  In some gardens this could be a problem with too many randomized plants.  Personally, I like the spontaneity of getting something growing unexpectedly.  (If they do get out of hand I can just pull them up or transplant them to a more desirable location.)

This Partridge Pea reached about 3' in height.  They can look gangly
in a manicured garden, but fit well into a naturalistic setting.

This year I started a number of new native annuals from seed.  In addition, I had some reseed from last year.  Here's a rundown on their performance in 2014.  I'll start with the best.

In early to mid summer the best performers were actually plants that had reseeded themselves from 2013:  Partridge Pea (Chamaecrista fasciculata) and American Pennyroyal (Hedeoma pulegioides).  Also the biennial, American Bellflower (Campanulastrum americanum) put on a big show.

The Partridge Pea has spread a little from it original planting.  This is an early transitional species, looking for gaps in the in the ground layer to germinate.  It can be pushed out of a densely planted area if there are no gaps.  

The seedpods of Partridge Pea curl up when they release the seeds.  These could look nice in a flower arrangement.

The American Pennyroyal forms dense low border 9-12" tall.
There is a little Selfheal (Prunella vulgaris) mixed in.

The Pennyroyal grew from a mixture of seed originally planted in spring 2013 and reseeding from plants in that fall.  The main feature of this plant is the strong minty scent that persists in the dried leaves and stems.  The blue flowers are tiny and grow from the leaf axils in late summer.  

These Amercan Bellflowers are at the back of a garden, an appropriate location.
They can get 5-6' tall in a sunny site.

In full sun the American Bellflower can get quite tall and unwieldy.  It grows well in shady spots reaching a more manageable height of only about 3'.  The blue flowers are very attractive to bees. Unfortunately deer seem to like it as well.  Although they left it alone after applying a repellent.  Pruned plants will produce a second flush of flowers.  

The narrow foliage of Plains Coreopsis allows to mix well
with other plantings without blocking the view.

In mid-summer and still continuing was Plains Coreopsis (Coreopsis tinctoria).  I transplanted some spindly seedlings in late June and by mid July they were taking off and blooming.  There was a little deer browsing early on, but this seemed to taper off after a treatment with Bobbex.  The native range of this Coreopsis includes Maryland so I am hoping that these will successfully reseed in the garden.

The two annuals that are still going strong into mid-fall are Yellow Sneezeweed (Helenium amarum) and Scarlet a.k.a. Hummingbird Sage (Salvia coccinea).  

I only got a couple of the sneezeweed to germinate, but once in the ground it took hold and has been blooming strongly since mid-August.  One trick with these is that the tiny seeds that I brought come massed together in few 1/16" spheres.  These need to be broken up and spread over the soil surface to germinate.  I mistakenly treated most of these spheres as seeds and planted them too deep resulting in no germination.  

The bright yellow flowers of this Yellow Sneezeweed do not need to be deadheaded.
Just as well, I hope to get some reseeding from these.

The Salvia germinated easily and after growing in trays for a few weeks were transferred to the garden or into pots.  These plants spent 6-8 weeks growing before they were ready to bloom.  Despite the wait, the blooming has been strong since early August.  This species also does well in pots. but it is kind of tall and you may want some other plants to fill in around the lower leaves.

The tubular flowers of this Salvia did attract our hummingbirds earlier in the season.
At 24-30" it shows up well among other garden plants.

Some other annuals I tried that grew but did not excel this season were Sulfur Cosmos (Cosmos sulphureus), Beach Sunflower (Helianthus debilis 'Pan') and Spanish Flag (Ipomoea lobata). The Cosmos suffered from too much competition from other plants and from being nibbled on by the local fauna.  I expect it would have done better in a more protected location.  The Sunflower germinated well in the garden but was overshadowed by the Annual Sunflower I paired it with.  The Spanish flag matured very late in the season with significant blooming starting in September.  It's blooming well now in late October, but all the supporting plants are fading away.  Spanish Flag is native to Mexico (part of North America); I don't expect to see this one reseed.

The fact that we have not had a real frost yet in our area has really extended the blooming season for these plants.  Some I expect to survive a light frost, while others will be killed immediately.  

I did plant a couple of winter annuals, Texas Bluebonnet (Lupinus texensis) and Miami Mist (Phacelia purshii), out in the garden in late summer.  I'm keeping an eye on them, but have not seen any definitive germination yet.

A Pollinator Border

When I planned my new vegetable garden last year I included a double fence design to help keep out the deer.  At the outer fence I planned for a border of pollinator-friendly native plants.  This border would help attract pollinators to the garden and also provide shelter for predatory insects to hang out.  By providing cover for the predators, damage due to insect pests is significantly reduced without the use of pesticides.

The border around the garden has a variety of native plants.  A bluebird is currently nesting in the box,
I try to avoid walking by, but it happens

The plants for this border need to provide pollen or nectar for the pollinators, be low maintenance, bloom sometime during the growing season and be somewhat to very resistant to deer browsing.  I also looked for plants that might deter smaller mammals that could burrow into the garden.  The garden location is in full sun and can get dry. 

Plants that are native to the area are the best choice for a pollinator garden.  These plants are natural food sources for the native insects that will be doing most of the work.  It is nearly impossible to find a single plant that will bloom the entire garden season, so a mixture of plants with staggered blooming times will provide some food for insects throughout the season.  The Xerces Society has guidelines for creating a pollinator friendly garden.  

When I put in the garden last year, most of the pollinator plants I put in were liners or seedlings.  Being young and of small size, they did not mature enough to bloom.  With a year in the ground they are really looking good now.  Here's a listing of plants I used in by pollinator border.

The earliest blooming plant in the border was Wild Columbine, Aquilegia canadensis.  The nodding red and yellow flowers are attractive to hummingbirds.  Blooming period is typically April through May.  The seeds are held loosely in the upright pods.  

I did not get a photo of my Columbine this season, but here you can see
the seed pods mixed in with some Black-eyed Susans.  I need to shake out
the seed pods to get more plants for next year.

Last year I planted both black-eye and Brown-eyed Susans (Rudbeckia hirta and R. triloba).  The deer were constantly eating the flowers and leaves of both species.  This year only the Black-eyed Susans returned.  I have been more diligent about spraying them with hot pepper solution, which seems to work.  While not as upright as Yellow Cone Flower (R. fulgida) I like the extended blooming season of R. hirta, lasting from June through September.

Here's Spotted Beebalm in a mixed border of Black-eyed Susans and False Pennyroyal.
The flowers are actually small yellow tubes hidden by the large pinkish bracts.

Spotted Beebalm, Monarda punctata, was grown from seed and actually matured enough to bloom the first year.  This year it really went to town.  Peak blooming season is June and July.  This plant is very resistant to deer browsing and attracts mostly bees and wasps.

This is a short-lived perennial so it needs to set seed to maintain a presence in the garden.

The flowers of Wild Bergamot are more exposed than Spotted Beebalm's
 making it easier for large butterflies to access them.

Another member of the Monarda genus in the garden is Wild Bergamot, M. fistulosa.  This is a much taller species, easily over 4 feet in this garden.  The flowers attract bees, butterflies and hummingbirds.  The bloom time is from early July through August.

These two Monarda species do well in dry to medium soils.  If the soil were moister Oswego Tea, M. didyma, would be a good choice, as well.

I had a difficult time with deer munching on the young Butterfly Weed, Asclepias tuberosa, plants last year.  This year they are doing much better and are coming into full bloom now (early July).

I have not seen any Monarch butterflies around these milkweeds,
mostly small greenish bees (Sweat bees?)

I have established a dense hedge of American Pennyroyal
 along one edge of the garden.
We'll see if it keeps out the moles, etc.

One of the first native annuals I put around the garden was American or False Pennyroyal, Hedeoma pulegioides.  This diminutive member of the mint family has a strong minty scent when touched.  It can act as a repellent for some insects, possibly mosquitoes.  I am interested to see if it will also discourage deer and small mammals from entering the garden.  Direct seeding in the garden last spring gave few plants, but these seeds came up in full force this year.  Despite what it says on the seed packet, fall sowing of some moist stratification (30 days, moist at 35-40 F) helps break seed dormancy.

I'm pretty sure this is one of the Nodding Onions.
I'll know better once it reaches full bloom -
will the flower continue to droop or turn upright.

Another plant to help form a barrier to invasion by burrowing mammals is Alliums.  I planted a long row of Nodding Onions, Allium cernuum, in the border. The idea is that they will be repelled by the presence of the onion bulb underground.  I've seen a few come up in the mix of plants, but sometimes they are hard to tell from the stray grasses also in the garden.  As we get later into blooming season (June-August) they should be easier to pick out.  

In the garden there is some white Yarrow, Achillea millefolium, that just blew in.  I also added a more colorful cultivar call 'Strawberry Seduction' to jazz things up a little.  I had problems last year with deer browsing, but not so this year.  Is this due to a more mature plant, or is it random choice by the deer?

I don't usually go for the flashy cultivars, but
I wanted to add some more red to the garden

The middle of the garden provides a refuge
for the more deer-sensitive species.

In the center of the garden I put a ring of tall flowers that was meant to draw the pollinator further into the garden.  Since these are more protected from deer, they don't have to be so deer resistant.  This year I have some Purple Cone Flower (Echinacea purpurea), False Sunflower (Heliopsis helianthoides 'Summer Sun', Beach Sunflower (Helianthus debilis 'Pan') and 'Autumn Beauty' Sunflower (Helianthus annuus).  The first two species bloom for the first half of summer and the sunflowers carry the load into the fall.

I selected the 'Autumn Beauty' cultivar of sunflower because it only grows to 6 feet, keeping it in scale with the rest of the plants and reducing the risk of tipping over.

My deer really like to eat various species of Helianthus, so I could not grow these in unprotected areas.  I'm not sure how they would treat the False Sunflower, but I'm sure they would give it a taste.  

Daisy Fleabane (Erigeron annuus) and Heal-all (Prunella vulgaris) are a couple of indigenous plants that have found a welcome place in this border.  Heal-all is edible (haven't tried it) and has many herbal/medicinal applications.  It can be used as a native ground cover, growing between 2 and 12 inches tall.

Heal-all is widely disbursed through the Northern Hemisphere.
It is a larval host for the Clouded Sulphur butterfly.

In the new part of the border I'm trying some new native annuals.  I have grown Sulphur Cosmos, Cosmos sulphureus, by direct sowing in Boston before.  It did germinate well in the border here, but has since disappeared.  I also sowed some Plains Coreopsis, Coreopsis tinctoria, in the same area.  Germination wasn't as good, but the plants are persisting.  In another area the deer sampled the Coreopsis, but did not actually eat it.  Another native Coreopsis species that could be used in the border is Threadleaf Coreopsis (C. verticillata).  It is easy to care for and fairly resistant to deer.

Plains Coreopsis starts out kind of wiry, but straightens up as it matures.

 One additional note about the border.  My outer fence is a 5-wire electric fence, but it is not energized.  If it were, it would immediately ground out because of all the plants growing on the wires.  If you have an energized fence it must be free of plants.  A flowering border should be sited well inside or outside the electrified wires.

New Seeds for 2014

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.

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. 

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. 

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.

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.

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.

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.

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.