Friday, December 9, 2011

Native Plants Update 2011

Now that most of the fall chores are done, I took some time to think about how some of my native plants were doing. My main focus is on those that I started from seed, but I have also put in some newer perennials and shrubs that put in as more mature specimens

New this Year from Seed

I successfully started the following species from seed this year.

• Pearly Everlasting, Anaphalis margaritacea, is a perennial, similar to the annual sweet everlastings (Pseudognaphallium obtusifolium) that I have had trouble transplanting into the garden in the past. These germinated well, but did not do well in ‘regular’ soil; however the ones that I put into a bed of decomposed bark chips seem to be taking hold. So it appears that these plants like a well drained, airy soil.

• Flowering Spurge, Euphorbia corollata, had limited germination but did grow well in the soilless mix. The transplants, like the Anaphalis above, showed a strong preference for lighter, well drained soils.

• Crowned Beggarticks, Bidens coronata, were difficult to germinate, unlike some of its prolific cousins. They did mature and bloom early in the season (June-August), but after setting seed this annual expired. This is in contrast to the Swamp Beggarticks that spend the summer growing to a good sized shrub before blooming in September.

It's nearly December and this plant has been trying to
bloom for awhile.  The arrow shows one of the trilobed
leaves for which this species is named.
• The woodland sunflower, Helianthus divaricatus, also had limited germination, but produced fairly strong plants. Like the Brown-eyed Susans, these have spent their first year in the ground getting established. These have a reputation for being aggressive, so they have been put under the Norway Maple.

• Brown-eyed Susan, Rudbeckia triloba, was difficult to germinate in moist sand. I did get better results with cold stratification in damp soil for 2 months in the refrigerator. These seedlings are spending their first year getting established in the soil, i.e., no flowers this year. Although with the extended warm weather this year there are a couple which have been trying to bloom since October.

Old from Seed

The following plants have performed well from seed in the past and I just wanted more of them:

• I really love the Orange Hummingbird Mint, Agastache aurantica ‘Navaho Sunset’, as much for the smell of its foliage as I do for the flowers. This perennial grows well from seed under lights and blooms the first year. Older plants are maturing to 2-2.5’ tall. So far I have not seen strong evidence of self seeding, but I believe it should.
Two shades of Sulfur Cosmos with
some American Bellflower in the back.
• Sulfur Cosmos, Cosmos sulphureus, are southwestern natives that grow and reseed well in garden soil in the Northeast. I had grown these in the past, but they were pushed out by my experiments with the more massive Bidens aristosa. I do prefer these in the garden since they are of more manageable size and have beautiful bright flowers. While they are fine left on their own, they do better, bloom-wise, with dead heading.

• Rock Harlequin, Corydalis sempervirens, is a favorite of mine, though, like many other natives this is not for general garden soil. It likes lean, well drained conditions. Some that I had growing in a pot, bloomed and started a second generation in an adjoining tray. I’m over-wintering these seedlings for next year. Once these plant have set a lot of seed they tend to peter out and die.

• The Indian Blanket, Gallardia pulchella, seeds that I got in Austin three years ago are still viable (refrigerator storage). These seeds produce variable plants that that will stand tall in the open or grow sideways to find an opening in more competitive environments. So far I have seen no evidence of self seeding in my New England garden, though the plants themselves need a good hard frost to kill them for the year.

• Cucumberleaf Sunflower, Helianthus debilis, is a Southeastern native that has made its way up the east coast as far as Maine. I got the cultivar ‘Pan’ three years ago and it seems to be coming back true to seed.

• Spotted Beebalm, Monarda punctata, is a short-lived perennial that is easy to start under lights and grows well in a variety of soils. After three years I am beginning to see signs of it spreading, just as the older plants are beginning to die off.

• I also bought the Texas native Drummond Phlox, Phlox drummondii, seeds in Austin three years back. Seeds stored in the refrigerator are still viable, and they will reseed themselves within a season, but I have not seen any overwinter up here naturally.

Purchased Native ‘Annuals’

This year I tried using all southwestern natives in my deck flower boxes. Just to be bold I went with a ‘primary’ color scheme: Mealy-cup Sage, Saliva farinacea, provided the blue spikes; I used Apache Beggarticks, Bidens ferulifolia, for yellow ‘fillers’ and the Drummond Phlox for a deep red, that I hoped would act as a ‘trailer’. I purchased the Sage and Bidens at a garden center and the phlox were from seed. While these plants survived the hot and occasionally very dry conditions, I found that the effect was compromised by ‘spotty’ blooming. The Salvia was a constant blue, but the Bidens tended to bloom in cycles that rarely coincided with the Phlox.

The Phlox is blooming while the yellow Bidens is between bloom cycles.

Returning on their Own

I have a fairly long list of annuals, biennials and perennials that are spreading mostly by seed. In managing these I need to be willing to toss out the extras (that I can’t give away) rather than let one or two aggressive species dominate. So here’s a quick summary of this years results:

• Red Columbine, Aquilegia canadensis reseeds well and stays ‘close to home’.

• Swamp Marigold, Bidens aristosa, vigorous self-seeder, but not too hard to pull out.

American Bellflower, Campanulastrum americanum, also a vigorous self-seeder, but grows in dry shady locations.

Strawberry Blite, Chenopodium capitatum, thought this was lost but it reappeared; this plant is too ‘sloppy’ for the flower garden, but it has other uses.

• Philadelphia Fleabane, Erigeron philadelphicus, mostly coming up from self-scattered seed in the lawn.

• Northern Sea Oats, Chasmanthium latifolium, was grown from seed started about 5 years ago and up until last year had been staying put. This past season I was finding it scattered around the garden. I have been moving the extra to underneath the Norway Maple, where this enthusiastic growth is needed.

• Sand Love Grass, Eragrotis trichodies, grows on dryish, sites with full sun. It produces attractive seed heads in early fall and slightly taller than it’s relative Purple Love Grass. This is a relatively short lived grass, so a decent seed bank will be needed to ensure its continued presence.

Biennial Beeblossom, Gaura biennis has been reseeding itself since I first planted it in 2008. Even with cutting back in the early summer, this biennial will reach 6’ tall.

American Pennyroyal, Hedeoma pulegiodes, has been reseeding itself consistently since 2008. It tends to concentrate in pavement cracks. When possible I have been moving this to more useful garden locations.

Scarlet, or Texas Sage
• Black-eyed Susan, Rudbeckia hirta, tends to stay close to the original planting location. My plants typically survive from 1-3 years.

• Scarlet Sage, Salvia coccinea, has been a surprise. It has reseeded itself in a variety of locations and matured on its own to give healthy, blooming specimens from July through September. Based on my experience with other red Salvias, I did not expect this one to come back so strongly.

• Showy Goldenrod, Solidago speciosa, spreads by both seed and underground runners. I have had to remove excess plants from the garden and am running out of places to put them.

• Swamp Verbena, Verbena hastata, is also an aggressive self-seeder. It grows in pavement cracks as well as in the garden.

New Perennials & Shrubs

In addition to the plants originally grown from seed, I put in the following perennials and shrubs. In the sun:

• Butterfly Weed, Asclepias tuberosa, is a tap-rooted perennial. It is found in coastal areas, so I am hoping that it will tolerate a roadside planting location.

• Sheep Laurel, Kalmia angustifolia, is a spreading shrub, growing to about 3’. I’m putting in place of some Meadowsweet that had grown too large.

Fall color of 'Blue Muffin' Viburnum
(a crimson colored leaf from a 'Winterthur'
Viburnum is to the back left).

In the shadier areas I added Canada Anemone, Anemone canadensis, Celandine Poppy, Stylophorum dipyllum, and Blue Stemmed Goldenrod, Solidago caesia. The Poppy and Goldenrod have performed well in the shade. The Anemone seemed to disappear after a month or so, but I could still find a leaf or two late in the season.

Finally, I added an Arrowwood Viburnum, Viburnum dentatum ‘Blue Muffin’, to the shrub border. Mainly I wanted to see how this oft used cultivar performs. So far my specimen stayed green longer than my 'Winterthur' Viburnum and, when the leaves did change, the coloration was fine, but not spectacular; a good foil for showier plants.

So, now I can start thinking about next year.  More on that later....


Sverige said...

Gorgeous shots - what a fantastic garden you have, My personal favorite plants are daylilies, purple coneflowers, and lupine.

Anonymous said...

I am experimenting with winter sowing methods and have a question for you. I am using a similar method to yours but with one big difference. I have sunken water jugs where I want the plants to grow permanently. I completely removed the bottom of the jugs and am hoping that I will then simply be able to remove the jug when the seedlings are big enough and in this way I can avoid transplant shock. Is there a reason that this wouldn't work?

Curtis said...

Your method should work quite well. If you are leaving the plants in place and avoiding transplanting the seedlings should be even better off. However, soil quality plays a role.

Curtis said...

To continue my comment... The soil used to plant your seeds into should allow for easy root development. Also pathogens in outdoor soil could pose a threat to new seedlings. You could create a pocket of soilless mix in the garden to plant the seeds into. The other concern would be moisture retention, since the soilless mix will tend to dry out faster than the native soil, however the jug cover may help with moisture retention. I wish you success with this experiment and would like to hear the results.