Monday, May 31, 2010

The Natives are Restless - What's happening as Summer approaches

As spring is drawing to a close, many of the summer blooming natives are getting ready to pop. This week I wanted to give an update on how the Native plants in my garden are doing.

I was very pleased to see that the Alleghany Vine, Adlumia fungosa, has begun to bloom with its little pale pink hearts. Last year it did not begin to bloom until mid-late June. This year I am letting it find its way in a more natural way, rather than forcing it to climb a trellis. In this way it is less likely to be twisted and broken off in the wind. IOt is a little difficult to see with its delicate frilly foliage and light colored flowers.  Now I just have to avoid stepping on it.

If these plants do well I will add in some new ones that I started from seed this year.  I hope that will get a stable population growing.

The little Rosy Sedge that I talked about a few weeks back is getting closer to bloom. This particular plant is so heavily shaded that the inflorescence, in fact, the whole plant is about half the size it gets in a more open location. I would never have spotted this development if I were not actively watching for it. I hope I can show you a good image when its flowers are actually open.
Correction: Two Stems of Meadowsweet

I have two native Spiraea growing here, Steeplebush and Meadowsweet, S. tomentosa and latifolia (or alba), respectively. While there can be easily distinguished by the different shapes of the flower spike, the leaves are also different. This is the first year that I could clearly detect the difference in the leaves. Steeplebush has a soft fuzzy leaf relative to the smooth leaf (glaborous) of Meadowsweet. In the photo you can also see that leaves of the Meadowsweet and more relaxed, but that is hard to tell if you don’t have a side-by-side comparison. While the habit of these two spiraeas is rather open, relative to the tightly mounded Japanese Spirea (S. japonica), I am surprised that these native species are not used more often in the residential landscape. In my garden Meadowsweet has proven to be a very versatile shrub, growing under a wide variety of conditions and blooming throughout the summer. It also can be pruned to tame it exuberant growth without compromising its ability to bloom.

The Red Columbine, Aquilegia canadensis, is still blooming away. Here it is shown with one of my Meadowsweet bushes just behind it.

Lastly, I planted two Winterthur Viburnums (V. nudum ‘Winterthur’) 4 years ago and they are both hitting stride now. (Their slow development was due at least in part to their proximity to the shade of a Norway Maple.) These buds will open to form corymbs of small white flowers. More interesting will be the pink and blue berries to follow.

Tuesday, May 25, 2010

American Bellflower

All around my yard I have mini-invasions of the attractive-yet-aggressive perennial Creeping Bellflower, Campanula rapunculoides, with is tall raceme thick with 1” purple bells. This European import is prevalent in disturbed areas, but according to Forest Service, it is not believed to be a threat to undisturbed natural habitats. When I learned about a native bellflower that also produced tall flower spike I got excited and got hold of some seed. American Bellflower, Campanulastrum americanum, is a biennial, spends its first year as a rosette of foliage and then launches its flower spike, up to 5 feet, in the second year. Despite the similarity in the name, the American (or Tall) Bellflower is a very different plant from its creeping cousin. Its flowers are like sky blue stars rather than bells and very tall flower spike is rather leafy and not as densely populated by blooms. Also, American Bellflower reproduces by seed only and does not form underground runners.

The native range for Campanulastrum americanum is from Ontario to Minnesota and south to Florida. As such, there are not any native populations in Massachusetts. Its native habitat is in moist borders and open woods. While it may grow in full sun, it prefers cool conditions.

I put in seedlings in all parts of my yard ranging from dry shade to full sun in well drained soil, to see just how they do. These plants survived in all locations. In areas with fertile soil and lots of sun, the flower spike reached nearly 6 feet. In the dry shade it topped out at about 2 feet and did not bloom as intensely. It even survived under a Norway Maple. It does reseed itself quite well, where the seed can find good soil. I have way too many seedlings this year, but they are not so prevalent as I get with the Swamp Marigold, Bidens aristosa, growing in the same area.  By recognizing the rosette with its 1/2-1" heart-shaped leaves, you can mange the population by transplanting or removing excess plants.

The flowering period is from July to October. The first flush is strong then blooming continues slowly throughout the summer. While not as full as the first flush, these plants will produce fresh blooms later in the fall. I tried cutting some flower stalks back to generate new spikes at mid-season, but this was not too effective. Maybe this year I’ll try that earlier. Seed that is produced early in the season may ripen quickly and germinate to produce a rosette that year, essentially functioning as a winter annual.

Also of interest, C. americanum is on a list for plants suitable for use under walnut trees, having both resistance to the juglone and a tolerance for shade. Hummingbirds are reported to visit this plant and it has been used to treat coughs and respiratory ailments by the Iroquois and Meskwaki Indians.

Seed for C. americanum is becoming more available. I was able to get seed from both Prairie Moon Nursery and the New England Wildflower Society (NEWFS). In discussing native plants with Scott LaFleur of NEWFS, he felt that despite its vigorous nature in size and reseeding, this plant could do really well in the garden. From my experience I see that it may find its garden home in the back of a shady border or in a cottage garden, where it leafiness will blend in with the other masses of plants.  Since this plant is not native to the New England States, I would not recommend its use up here in areas near to natural areas where its seed may escape.

Monday, May 17, 2010

American Pennyroyal - Another Native Groundcover

While it may be a little late in the season to talk about starting annuals from seed, but I thought American Pennyroyal was worth mentioning here. It is a tough little plant that grows in dry, partly shady locations and is quick and easy to germinate.  It has a low-growing (6-12”) and spreading habit qualifies it as a native groundcover.

American Pennyroyal, Hedeoma pulegioides, is a low growing herb of the mint family that has been used extensively by both Native Americans and the colonists for its medicinal properties. Medicinal uses include treatment for colds and fevers, as a gastrointestinal aid (‘warming to the stomach’), and as flavoring agent in foods, like tea and ice cream. The colonists readily accepted this herb as a replacement for the European or English pennyroyal (Mentha pulegium) that they were accustomed to using. The plant is rich in a pungent, volatile oils including pulegone (whence the species name), which holds most of the medicinal properties; however, large doses are reportedly lethal. For the hikers, rubbing the leaves on your skin repels mosquitos and other biting insects.

The plant grows in dry upland woods and can occur as rather dense colonies. In nature, it is often found growing in openings in the woods and along paths. The native range runs all along the East Coast (except Florida) and west to Oklahoma and North Dakota.
Small blue tubular flowers are borne in the leaf axils of the erect stems from July to September. While the flowers do attract some tiny insects, they are difficult to see unless you get down on your hands and knees.

The real garden value of this plant is in its aromatic character and its ability to grow thickly in dry partly shady conditions. I am putting it along walkways so that you get a burst of the minty aroma anytime it is disturbed, or stepped on. I started my first ‘crop’ in 2009, with seed from Companion Plants, and am seeing new colonies springing up in adjacent areas. It is easy to distinguish from other sprouts, because as soon as you touch it you get a whiff of its minty aroma. This is a good example of what I am looking for in a native annual, that is, an annual plant that is able to persist on its own without my direct involvement and has desirable garden traits. In the case of American Pennyroyal those are its stimulating aroma and ability to grow in dry partly shady locations. 

Monday, May 10, 2010

Native Ground Covers - Part 2

In the last post I listed some of the herbaceous and small woody native plants that I have been using as ground covers. Sometimes you want that grassy look. There are a number of options for low maintenance grasses as alternatives to the Non-Native Kentucky Blue Grass and Perennial Ryes commonly used in residential lawn grasses.

One option to the conventional lawn is the use of fine fescue grasses.  These have a silkier appearance and tend to be a lighter shade of green than KBG.  Two commercially available seed mixes based on blends of fine fescue grasses are ‘No-Mow’ Mix from Prairie Nursery and Eco-Lawn from Wildflower Farm. These mixes contain a blend of creeping and clumping fescues, some of which are native to North America, which will tolerate a range moisture and light of conditions. Lawns of these grasses are reported to require very little mowing (1-4 times/year), little additional water and no fertilization.

Another option is to do a sedge lawn. Sedges, members of the genus Carex, number about 2000 species world-wide, with about 480 representatives native to North America. With so many species, there are some that are adapted to nearly any growing condition. In general, they look like average grasses. This genus can be distinguished in that sedges have triangular, not round, stems. When viewed down the stem the leaf blades radiate off at 120-degree angles. Sedge lawns are a better choice for wet conditions than fescues, however they do not tolerate foot traffic as well. Brooklyn Botanical Garden has a useful article on sedge lawns.

The first sedge that I became intrigued with was Rosy Sedge, Carex rosea. I saw this ‘in bloom’ in a friend's yard with its tiny (~1/8th inch) rose or star-like, tan colored inflorescences. These come in late spring. Otherwise, it just looks like grass. Unfortunately, I do not have a photo or these little flowers at this time, but here’s what it looks like without them. While it is naturally distributed over the eastern 2/3rds of the U.S., I do not know of a commercial source for this sedge.

Since first seeing Rosy Sedge, in 2006, I have become more interested in these plants. Two sedges that are available and well adapted for use in the Northeast are Pennsylvania Sedge (Carex pensylvanica) and Appalachian Sedge (C. appalachica).

Appalachian Sedge forms clumps with mid-green blades 8-24” long. These clumps do not produce rhizomes. The bloom time is in late spring, with seeds forming in late spring to early summer. Its native habitat is in dry to mesic deciduous forests and its native range includes the eastern states from Georgia to Canada. In my yard I have it growing successfully under a Sycamore Maple (another invasive tree). The foliage turns tan over the winter, but it greens up rapidly in the spring.

Pennsylvania Sedge is becoming much more available in the nursery trade. It is a little smaller than Appalachian sedge, with leaves at 4-18 inches. It is reported to tolerate occasional mowing (I haven’t mowed mine yet on purpose, anyway). Also it does spread slowly by rhizomes, a good trait for a lawn grass. The inflorescences appear in early spring as dark brown spikes, just above the foliage. These come before and are easily distinguished from the flowers of Appalachian Sedge. This sedge is found in well drained acidic, but rich soils in and along hardwood forest edges and openings. The native range includes the eastern states from Georgia to Canada to just west of the Mississippi River. My Pennsylvania Sedge is also doing well under the same maple tree. Mine is a bit larger than the Appalachian Sedge, but it has been in the ground a year or two longer. For me the beauty of both of these grasses is that they do well in DRY SHADE!!!

For more general information on growing alterative lawns check out the following links:
>Planting a ‘No-Mow’ lawn. This link also has a clear and concise statement on growing/encouraging moss.
>Native Grass Lawns: Lots of information on a variety of altenatives
>Planting a Native Grass Lawn. This is another useful link for the Brooklyn Botanical Garden site.
The book, Easy Lawns, edited by Stevie Daniels, gives information on growing low-maintenance native grass lawns appropriate to each region of the U.S.