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.

Snowplows and Roadside Plantings, a Case for Native Annuals

Last week I did the spring clean-up of a roadside bed I designed. The plants used were all Eastern North American species.  As I was working I was reflecting on what did and did not work well. For the most part it has been doing quite well with little input from me. Up away from the main traffic flow Aronia (Aronia arbutifolia), Meadowsweet (Spiraea latifolia) and Shrubby Cinquefoil (Potentilla fruticosa) are growing well as are the perennials including Prairie Aster (Symphyotrichum turbinellum), Purple Coneflower (Echinacea purpurea), Appalachian Blazing Star (Liatris squarrulosa), Stiff Goldenrod (Solidago rigida), Red Columbine (Aquilega canadensis) and my favorite grass, Prairie Dropseed (Sporobolus heterolepis).



When I designed this roadside bed back in 2006, I selected plants that I thought would withstand drought conditions, salt spray, full sun and wind. The one aspect that I had not fully appreciated was tolerance to disturbance, particularly resistance to snow plows! Where the bed is protected by a curb there is not much of an issue, but down near the highway the surface of the bed is often scraped over, either directly by the plows or as a result of snow being pushed up and over the sidewalk.

    

When I first learned that blueberries were salt tolerant I happily incorporated them into the roadside position.  I thought people going by would be impressed at how versatile of a shrub blueberries were. I was shocked the following spring when I found the bushes pushed nearly a foot further into the bed, the result of plowing of the snow. Well, the plants are still there 4 years later, but just hanging by a thread. This is obviously the wrong place for what would otherwise be the right plant.



Problem area, after a fresh layer of leaf mulch. 
The blueberry twigs are still in there.



Down by the road Seaside Goldenrod, Solidago sempervirens, is performing well. In fact, this is an example of a native species that is expanding into the urban environment in disturbed areas where road salt makes it difficult for other species to establish. The Prairie Dropseed in this area (those that haven’t been plowed over) are not doing as well. However, Sand Love Grass, Eragrostis trichodes, a new addition to this area does seem to be doing better.

Considering the conditions at this end of the planting I really need a plant (or plants) that will have a continued presence despite a nearly annual scraping of the top layer of soil. Use of a native annual, or perennial, that vigorously self-seeds should fit the bill. Since the plant starts each year anew, disruption of the crown and roots would not be an issue.

This year I have seeded in some American Pennyroyal, Hedeoma pulegioides, a true annual that grows in dry disturbed locations and produces a lot of seed. I also added seeds for a couple of perennials, Spotted Beebalm, Monarda punctata, and Butterfly Weed, Asclepias tuberosa, that are known to reseed effectively and have some salt resistance. By starting from seed I am testing whether this site has the right conditions for germination, a critical factor if they are to get established there.

To get some new ideas I turned to the Advanced Search  function on the USDA Plants database. Here I looked for plants that will tolerate full-sun, drought and salt. While not every plant in the database is searchable in this way, it can provide many leads. Among the results was the Seaside Goldenrod that is already thriving there. A new lead that was generated was Beach Sunflower, Helianthus debilis. I’ve been growing this from seed in pots at home for a couple of years, now it’s time to put it to the test in the field!

Natives in Pots

There are many reasons to grow outdoor plants in containers. You may not have space in the ground, or they can be used as decorations on a deck or patio, or you may just want to bring the plants closer to where the people are. The main reason I have been growing native plants in pots is that I do not have the right growing conditions in the ground to raise the the plants I want from seed. This is particularly the case for annuals from some of the hotter parts of the country.

Here are some of the plants that I am growing this year. Lantana, Lantana camara, is technically a North American native, since its native range includes Mexico and Puerto Rico. It behaves well as a bedding or potted plant in colder climates, but it is invasive in the warmer parts of the US, particularly Florida and Texas. I really love the red-orange-yellow multi-colored flowers and long blooming period.  These I bought from a nursery and mixed in with other classic annuals like the Lobelia, shown here.  The rest of the annuals I have grown from seed.

While on a trip to Austin, TX, I picked up seeds for Drummond phlox, Phlox drummondii, and the annual Indian Blanket, Gaillardia pulchella, at the Lady Bird Johnson Wildflower Center. These appeared to be species plants and not any crazy cultivars. So far the Phlox has made it to bloom, with its scarlet red flower. The Indian blanket is just a week or so away. Another Texas native I have growing in pots and in the ground is Scarlet Sage, Salvia coccinea. None of these plants really started growing until the temps here got well into the 80’s.

I was really happy to see that some seed from the Beach Sunflower, Helianthus debilis ‘Pan’, that I grew last year had germinated in the same pot. Native to the Texas coast, this species has spread up the East Coast all the way to Maine. Here it is in bloom last year in the same pot. I have also grown Bearded Beggarticks (Bidens aristosa) in pots. Given half a chance, this eastern native reseeds itself readily.

Some native annuals that I had in pots last year are Devil’s Claw (Proboscidea louisianica), Yellowdicks (Helenium amarum ‘Dakota Gold’), and Bird’s Eye Gilia (Gilia tricolor).

The native perennial that I have in a pot is the Crimson-eyed Rosemallow, Hibiscus moscheutos, that I bought from the New England Wildflower Society. While it is native to New England, I just don’t have the sunny moist site it would like to keep it in. I over-wintered this in its pot by storing in a plastic bag with salt marsh hay in an unheated garage. It looks pretty happy so far. The blooms are expected in late summer.