Monday, April 11, 2016

New Plants for 2016

As we are approaching another planting season I've come up with a list a new native plants to add to our landscape.  Most of these plants are to build on the existing communities.  My main goals are to  provide food for wildlife, displace invasive species, stabilize soils and add visual appeal.  To help me determine what is native here near the Potomac River, I am using a guidebook from U.S. Fish and Wildlife Service for most of my plant selection.

One area, shaded by white pines and red cedar, is densely populated with Vinca minor.  I trying to  to get rid of that and replace it with a variety of shade loving native species.  I am having some good success with green-and-gold, Chrysogonum virginianum.  It is filling in nicely with a dense mat of evergreen foliage.  Foamflower, Tiarella cordifolia, is spreading slowly, so I will be adding more of those to give them a boost.  I brought some hairy alumroot with reddish leaves, Heuchera villosa var. atropurpurea, from my Boston garden and it has survived well.  When I saw it offered by Prairie Nursery I ordered a bunch more.

Here's a mixture of seed grown Heuchera villosa, both green and red-leaf forms.

This woodland phlox grows all around our property,
mostly in the shady woodlands.

I will try adding some woodland phlox, Phlox divaricata, to the mix this year.  It's growing wild nearby, so it will be a truly natural extension into this space.  I thought that this needed moist conditions to do well, but I read somewhere that it could also grow in drier shade conditions.  We will see if that's true.

One species that is not native to this region that I am trying out this year is rose vervain, Glandularia canadensis. It is a native groundcover from the Mid-West and South.  It is a perennial in warmer areas, but otherwise it's a reseeding annual.  I was inspired by the cultivar 'Homestead Purple' that is heavy blooming and hardier than the species in cooler climates.  Rather than buying the individual plants of the named cultivar, I decided to start some from seed.  These plants won't necessarily be the same, but I'll get a feel whether I like it enough to invest in the cultivar.  Deer and rabbits like these too, so we'll see if any survive.  If successful, these would be a nice ground cover to use around shrubs in sunny locations.

I would like to establish some Liatris in our gardens.  The mid-summer blooms are very popular with a variety of pollinators.  Unfortunately, the spike gayfeather, L. spicata, that I've planted has also been popular with our rabbits and/or groundhog.  This year I will try adding scaly blazing star, Liatris squarrosa,  This species is native to the nearby Piedmont region of Virginia.  Maybe its rougher texture will be less palatable with the local herbivores.

Another new addition to the garden will be vasevine, Clematis virona.  The purple bell-shaped flowers appear in mid-summer.  I will plant these along a fence in open shade/part sun and mesic soil. I planted virgin's bower, C. virginiana, this same area area several years ago and it has taken hold quite well.  If all goes as planned, as the vasevine flowers finish blooming the virgin's bower will kick in.

I am trying out Bushy St. Johnswort, Hypericum densiflorum, for a second time.  I was unsuccessful past, but that was in a fairly shady location.  This time I'll give it more sun and a more consistent supply of moisture.  If it finds this a suitable spot, it is supposed to spread thickly.

As I mentioned in my last post, I am removing invasive plants from a hillside hedgerow and replacing them with natives that spread out forming clonal colonies.  These clonal shrubs will help hold the hillside against erosion.  The two species I'm adding this spring are American hazelnut, Corylus americana, and gray dogwood, Cornus racemosa.

In addition to the soil holding properties, American hazelnut also produces edible nuts
that benefit wildlife, or humans (if we can get them).  In this photo
you can see male catkins emerging above the dried leaves.



Gray dogwood  has small white flowers on terminal racemes
in late spring.  After foliage drops in the fall the shrub is distinguished
by the few remaining white berries on  bright red stems.




At the end of March the lowbush blueberry flowers were just beginning to open.
 No flowers yet on these cultivated strawberries.
Two years ago we planted several native lowbush blueberries, Vaccinium angustifolium, and some cultivated strawberries that I got from a Master Gardener sale along the walk to our front door.  These have performed quite well and are beginning to spread.  Since I am all about native plants, I will be adding some of the native Virginia strawberries, Fragaria virginiana.  This species is one of the two originally hybridized to create the modern cultivated strawberries we all enjoy.  Though small, the Virginia strawberries are packed with flavor.



Got these as bare root plants and potted them up until
the meadow gets its annual mowing.
I never thought I would need to but I am adding some eastern red ceder to the meadow along its wooded edge.  I would like to have a few evergreens growing in that area.  There were some indigenous seedlings, but they disappeared.  I fear the deer have chewed them to the ground.  I'll put some cages around these for a couple of years.

Now I just need to get to work!

Monday, March 7, 2016

Goals for 2016 season



As spring is rapidly approaching I'm finishing up my plans for what I'd like to accomplish this season.  One of my primary goals is to continue to control and eventually eliminate the invasives.  Most management strategies call for eliminating to satellite  populations first to control spread and then work toward the center.  Based on published guidelines such as from the US Forest service, I'm using the following techniques:
  • Stilt grass, Microstegium vinineum, by managed mowings, timed pulling in late July or August and displacement with natives/manageable species.
  • Oriental bittersweet (Celastrus orbiculatus), wineberry (Rubus phoenicolasius) and autumn olive (Elaeagnus umbellata) by mowing or cutting then treating the stumps with glyphosate at 20% concentration.  (Herbicide treatment is more effective in late summer and fall.)
  • Japanese honeysuckle (Lonicera japonica) and multiflora rose (Rosa multiflora) by pulling, or cutting back and treating the stubs with glyphosate.
  • Garlic mustard (Alliaria petiolata) mostly by pulling when the ground is soft, making spring a good time to work on this.  However, I will do a foliar spray with something like glyphosate for massive infestations.  Later in the season remaining plants will get cut and bagged to prevent seed dispersal.
If I can't get into the base of the plant to kill it, I will cut them back to keep them from setting seed.  Check for local restrictions on pesticide use and follow published instructions for proper use.



I initially cleared this area in spring 2014 and have
been cutting back undesired shrubs each spring.
I am managing a meadow conversion with early mowing and adding more native shrubs to the back edges, like Eastern red cedar (Juniperus virginiana) and gray dogwood (Cornus racemosa).  Invasives to target in this area are oriental bittersweet, Japanese honeysuckle and wineberry.  This is an area that I also seeded with some native annuals and perennials I had growing elsewhere on our property.

Here's how that area looked last September.  The dominant plant here is wingstem, 
Verbesina alternifolia. which is a very common native in this area.

Of the small trees and shrubs I added in previous years the elderberry (Sambucus canadensis) and American plum (Prunus americana) are doing well.  The chokecherries (Prunus virginiana) and smooth sumac (Rhus glabra) will still need some protection and nurturing, but they seem to be surviving in this minimally managed area.


At the beginning of March the elderberries are beginning to leaf out.


In the middle of an open lawn we have a mature butternut tree (Juglans cinerea).  It has a nice upright form and open canopy that works well in the middle ground.  It's easy to walk under and you can get glimpses of the distance through the branches, even when the leaves are out.  Unfortunately this tree, like many other butternuts in North America, is in decline.  This is likely due to a fungal infection that currently has no treatment.  Since this tree is still producing fruit I will try to keep it for a few more years.  But, since I know it will fail before too long, it's time to look for a replacement.  After considering a number of possibilities, I have settled on trying a Sassafras tree (Sassafras albidum).

Here's the butternut in fall of 2013,
it's lost a couple of branches since then.
The Sassafras has a similar upright form and is of moderate size (30-40') so it will not monopolize the space.  Also, like the butternut, it has an open canopy.  Instead of nuts, the sassafras is a berry producer.  If I am lucky enough to get a female tree, I should get berry production for the birds, since there is a nearby native population of these trees.  My plan is to put in a small specimen a few feet to the south of the butternut to let it get started before I have to take the butternut down.






Here's a mature Sassafras at Mount Auburn Cemetery.
Not only does it have a nice open form, it has great fall color.


Another area that I am focusing on this year is a hedgerow on a steep hillside.  The goal is to remove the invasives without destabilizing slope and to repopulate it with natives.  Japanese honey suckle is the predominate invasive in this area.  Late winter is a good time to spot these vines since they still have green leaves.  The ground is soft and moist so pulling is relatively easy.  For the plants that won't pull out, cutting the stems close to the ground and treating with 20% glyphosate.  This is effective as long as the ground is not frozen and it is less disruptive to the soil.

Other invasives that are easy to spot and pull now include multiflora rose, garlic mustard, wineberrry and Vinca minor.  I've already put in some smooth sumacs and Persimmon trees.  This year I'll add some gray dogwood and bushy St Johnswort, Hypericum densiflorum.  As I fill this area in with native shrubs and perennials that provide full season benefits for the native fauna, I can start eliminating the butterfly bushes that are of limited use to wildlife.

This rather messy area is a tangle of Japanese honeysuckle, wineberry (the red stems)
and butterfly bushes mixed in with desirable plants like wild blackberries and smooth sumac.
There is about a 5' difference in grade between the top and bottom of the slope,
 so I am trying to avoid pulling out all of the existing 'bad' plants.
The green leaves on the Japanese honeysuckle make it easy to target in late winter,
before the other plants begin to leaf out.





Monday, February 15, 2016

Native Plant Information on Houzz

For the past 18 months I have been writing profiles of native plants for the mid-Atlantic region for the website Houzz.  While much of the content on this site is focused on interior design, they are making a concerted effort to spreading the news about native plant species and how to use them in residential design.  Also, many of the gardening and landscaping articles focus on responsible and sustainable design.

They have a number of writers from different parts of the U.S. doing profiles on useful plants native to their region.  Writers for other regions of the US include: Ellen Sousa for the Northeast, Benjamin Vogt for the Central Plains,  Heather Holm for the Great Lakes, and  Noelle Johnson for the deserts/southwest.  

Also on the website you can find articles on a number of specialty issues like drought tolerant plants, trees for wet soils, and native grasses to name a few. I encourage you to check out the resources on landscaping and native plants on Houzz.

Here are links to a few of my articles:

Thursday, January 7, 2016

Mystery Solved! Unknown Fern Identified!

East-facing hillside off the back of our property
It's early January and finally getting cold here in Maryland.  Now that there is not a lot of green leafy cover, it's a good time to spot some small evergreen native plants.  Most of the recognizable of these now are evergreen ferns, such as Christmas fern (Polystichum acrostichoides) and ebony spleenwort (Asplenium platyneuron).

As I was taking a look around I found another clump of a small evergreen fern that I have been trying to ID for the past two years.  It's growing on a wooded hillside off the back of our property.  This time with the one I found had fertile fronds showing the spore-producing sori underneath.

Unknown fern as I found it in January 2015; with only sterile fronds present.

Pictured here is a similar plant a little further down the hill.  In addition to the closely paired sterile pinnae at the base, this one has much longer stems bearing fertile pinnea (leaflets).
Fertile fronds are longer, 8-10", growing out the the center of the clump. 

With the additional information on the shape and placement of these reproductive organs I could make some more guesses at its identity.  The sori are brownish and fuzzy and are surrounded by 5 or 6 appendages that give them sort of a star-like appearance.  The sori are scattered midway between the center and midrib of the pinnea.

Close examination of the undersides of these fertile fronds show the reproductive organs, the sori.

Using a fern guide (Peterson's) I keyed it out to be of the genus Woodsia...but which one?  Since it has few hairs on it I really got stuck on it being smooth woodsia (W. glabella).  But that fern is rare and its range is much further north  in northern New England and Canada.  
So, while it is not normally in my nature, I decided to ask for help and posted my photos to on-line group that helps with native plant ID.  I quickly got a suggestion to consider it as blunt lobed cliff fern, Woodsia obtusa.  This is a relatively common species in eastern US and its description lined up pretty well with my plant.  What was throwing me off was the drawing in the guide showing lots of hairs and glands on the rachis (central stem).  Looking at images of Woodsia obtusa on the internet from knowledgeable sites showed them to be consistent with the plant in our 'backyard'.

Fern ID is tough and it is good to have multiple resources to help with ID.  Also getting assistance from other plant enthusiasts can be an invaluable learning experience, and a great savings of time, too. Thanks to all of you out there!

Tuesday, December 1, 2015

Fall's Second Season

Even though all the blossoms are gone there are still sights to delight the eye in the fall garden.  Rather than the purples and golds of aster and goldenrod flowers, we get whites and silvers from the seeds and seed heads of many of these same plants.  The lower angle of the winter sun magnifies this effect, causing them to nearly glow with reflected light.

This photo was taken on a mid-November morning.  Some of the plants from
left to right are little bluestem, New England aster, purple top (grass) and Canada goldenrod.

Sweet everlasting, Pseudognaphallium obtussifolium, has a particularly long-lasting presence in the garden.  Even after the seeds are dispersed the white, star-like sepals remain intact well into January.  This plant is an annual and depends on this seed finding a spot on the ground to continue its presence in the garden.

The spent flowers of sweet everlasting show off well in front of a dark back ground.
Mixed in here are the seed stalks of the native grass, purple top, Tridens flavus.



Virgin's bower, Clematis virginiana, is one of our native clematises.  It has a very long vining habit, growing to about 20 feet in sunny location in one season.  Many consider it weedy because its thin stems go just about anywhere.  I like it because it does a good job of covering  fences  with foliage without becoming heavy and damaging like the exotic sweet autumn clematis.  The flowers in the second half of summer are small and rather subtle compared to many cultivated clematises.  Where this plant shines (or glows) is in the fall when the feathery seed heads form.  




After the fluffy white seeds of New York ironweed are dispersed
these rust colored capsules will remain for several months.
Another fall star is New York ironweed, Vernonia novebaracensis.  By the end of October the magenta flowers are all gone, replaced with the rust-colored seed heads.  As winter wears on these breakdown and become less fluffy; however the star-like sepals remain into the new year.




Besides all these flowering plants, the grasses also make a graceful contribution to the fall and winter garden.  Last fall I wrote a blog post about fall grasses.  I won't go into a lot of detail again, only to say that some of them really do use the winter light to great effect, such as pink muhly (Muhlenbergia capilaris) and little bluestem (Schizachyrium scoparium).




Little bluestem also takes on a distinct copper hue that makes it easy to spot at a distance.  Northern sea oats (Chasmantheum latifolium) also has a distinctive form with its dangling seed heads and rich brown hues.  Also on the property I have several large patches of deer tongue grass (see last fall's post).  What I noticed this year was that, while not particularly beautiful in form, the stiff dried leaves made a very pleasant rustling sound when there was just a little breeze.



While leaving perennials and grasses standing over the winter offers some visual interest to an otherwise flat landscape, it is also a good practice for the ecologically minded gardener.  Seed heads left standing provide food for migrating and non-migrating birds.  Standing twigs provide winter cover for many small animals and insects.  The larvae of many butterflies over winter in the leaf litter.  Many insect predators overwinter in the ground cover.  By providing space for them you will have a leg up come spring on your pest control.  (There are situations were fall clean up is advised, particularly for plants battling a fungal or bacterial infection where spores can overwinter in the leaf layer.)


Appreciating plants in the fall is not just an outdoor activity.  We brought in a few to enjoy as a table center piece.  While pretty this has proven to get a little messy.  The seeds  on the little bluestem stick quite tightly to the table cloth and the hosta seed head is still shedding seeds.  Our biggest problem is that our cat likes to get in and rearrange things, even the spiny branches of the invasive wineberry (Rubus phoenicolasius).
Some of the plants from left to right, Northern sea oats, a wineberry stem, little bluestem,
false indigo pods, tall ornamental garlic, hosta and wild bergamot.



Wednesday, October 28, 2015

Collecting my own seed

I've been trying to figure out what to plant in the areas where I've been pulling out the Japanese stiltgrass.  I want to use native plants and I'd like them to be as local as possible.  As I was taking some autumn photos, suddenly it hit me.  Why not use the seeds that my native plants are producing right in my own backyard (duh)!!!  This is perfect.  By collecting seed from around my property I'm getting plants that are adapted to the local area.  I can also make a good guess at where the plants will grow well.  Of course not every seed I put out will germinate but the seeds are free and the investment in labor is minimal.  The seed I am collecting now are from late summer and fall blooming plants.

Here's what I've collected so far:

The ripe seed heads of this Sallow Sedge fell apart into individual
seeds when I touched them making them easy to harvest.


Sallow sedge, Carex lurida, is pretty common on my property.  It forms dense clumps that mature to 2-3' tall and wide.  It grows best in moist to wet soils and partial sunlight.  I have small clumps of it growing in the lawn, but these can't reproduce since they are getting mowed down regularly. The leaves are long and have a deep fold along the midrib.  This gives it a stiff texture.

I'll scatter the seeds along the woodland edges where the soil is moist and there are several hours of good sun each day.  It is also an area where I am trying to remove the invasive wineberry bushes, Rubus phoenicolasius.  The dense clumps may make it a little harder for these bushes to spread.


The seeds of bottlebrush grass are easily stripped off from
bottom to top.  Trying to go the other direction leaves most
of the seed still attached to the stem.



Bottlebrush grass, Elymus hystrix, is a common cool season grass of the northeastern quarter of the US.  Most of the plants I have were purchased, however I have seen some growing remotely.  So I may have some indigenous plants, or they are just really good at spreading.  This species is most noted for the flowers and seed heads that resemble a bottle brush.  The flowers appear in early summer and persist until fall.  

The plants grow from 2 to 5 feet tall and do well partial sun and soils with medium moisture levels.  I will plant these along the edge of a path where the soil drops away.  The height of these plants should still make them easy to see.

The seeds are relatively large.  One ounce typically consists of about 7,500 seeds

Ripe seeds are assisted in wind dispersal by the fluffy white appendages.
Some flowers still in bloom are at the lower right in the photo.

Tall Snakeroot, Ageratina altissima, formerly Eupatorium rugosum, is very common in this area.  It is particularly evident in my area along roadsides near the Potomac river.  It grows well in full to partial sunlight and a range of soil moistures.

It is tolerant of soil disturbance, making it a good candidate for an edge habitat where plants are occasionally mowed down.  I'll scatter these in some of the drier woodland edge areas.

The seeds are tiny, typically 150,000 per ounce. They require light for germination.  This is common for disturbance adapted plant species.


Here most of the fluffy seed of the Sweet Everlasting have 
been blown away, leaving the sepals as 'everlasting' flowers.


Sweet everlasting, Pseudognaphalium obtusifolium, is a native annual that depends on disturbance for survival.  It is most common recently cleared areas in full sun and dryish soils.  I have a recently cleared meadow area that will be perfect for these.

This plant is evident in a border because the fine hairs on the leaves and stems catch the sunlight and make it look like the plant is glowing.  The tiny white flowers never fully open but form white clusters of buds that show well.  After blooming long-lasting bracts remain giving the effect of an everlasting flower.

The seeds of this species are really tiny, coming in at 500,000 per ounce.  It is hard to find the actual seed, there is so much fluff attached. These seeds are quickly wind dispersed, so I need stay on top of harvesting them.




Short's Aster, Symphyotrichum shortii, is found in the mid-Atlantic and mid-western states.  This aster is the latest blooming species that I have growing.  It starts in about mid-September and continues to the end of October.  Besides its long and late blooming cycle, it is also tolerant of dry shade and alkaline soils.  This makes it an excellent candidate for deeper into the woodland areas where it can compete with the stiltgrass for patches of light and openings in the canopy.

Each seed of Small's Aster has an attached pappus that looks like a little umbrella that catches the wind.  The actual seeds are larger than the previous two species, with about 60,000 per ounce.

In the center are some ripe seeds with their fluffy pappus.
In the background you can see some or the lavender
flowers still in bloom.
So these are some of the later blooming species that I will try to 'seed' into the stiltgrass infected areas.  There no reason I shouldn't harvest some of my spring and early summer species and do the same.

Tuesday, October 13, 2015

Stiltgrass management, part 2

After trying to remove as much Japanese stiltgrass as possible in late summer, the next step is to fill in the gaps with more desirable plants. My approach last year of seeding in native grasses like Canada and Virginia ryes did not work out too well.  There were some good reasons for my disappointing results.  I needed to plant  these relatively large seeds more deeply to get better germination.  Also these new grass seedlings need 2-3 years to establish before mowing back, or using as pasture.  It would be better to use these big perennial grasses in a meadow planting where mowing is done only once a season.

This year I am trying a more conventional route with the filler grasses.  I will be using commercial turf grasses that are selected for rapid growth and formation of a dense turf layer.  This is what I need to exclude the stiltgrass.  By planting these cool season grasses in the fall they have a chance to germinate and fill in before the stiltgrass starts growing in mid-spring.

I divided up the stiltgrass infected areas into full sun, part sun and mostly shade and selected a seed mixture appropriate for each condition.  For full sun I selected a blend of tall fescues with just a little Kentucky bluegrass.  For the part-sun areas I have a blend or both tall and fine fescues with a little perennial rye and Kentucky blue grass.  For the shade areas I am using a blend of fine fescues selected for low maintenance.  This year I am using Eco-Grass from Prairie Moon, but there are other blends such as No-Mow from Prairie Nursery and Eco-lawn from Wildflower Farm that should work as well.

Most commercially available cool-season turf grasses are not native to North America with the exception of some of the fine fescues, in particular red fescue (Festuca rubra).  You can find detailed information about which turf grasses are appropriate for your region from your state's cooperative extension.  For example the Maryland Extension Service has a listing of recommended grass cultivars that were tested locally.

Before buying seed this year I shopped around to see what specific seed cultivars were used in each of the blends.  There is usually a tag with the detailed seed composition somewhere on the bag. When I went out to buy the one I liked, I found that that specific blend was no longer available even though the product name on the bag was the same.  Frustrating!!!  I imagine that the retailers are still trying the produce an equivalent performing product, but it still, that was a frustrating experience.

The first step in the reseeding process is to remove the stiltgrass thatch in the lawn.  This opens up spaces for the new seed and may help remove some undispersed sitltgrass seed.  Since late in the season much of the remaining stiltgrass has had a chance to set seed, this thatch needs to be segregated from regular compost and the regular brush piles.  I have a couple of piles dedicated to stiltgrass so that it does not get mixed up with the regular yard waste and I can monitor it for spreading.  Another option would be to landfill it in thick plastic bags.  You do not want to let the stiltgrass get out and spread its seed.

Late September is when the stiltgrass begins to die back.  The brownish areas are easy to spot.
Once the area was clear of thatch I applied the new seed.  I used the back side of a bow rake to press the seed into the soil.  The nice thing about the conventional turf seeds is that they do not need to be planted deeply.  After sowing, it is necessary to keep the new seed bed moist until the new seedlings are established. I usually try to time my seed sowing with coming rains.  That way I don't need to water it in (I'm really lazy in that way).  Besides the cooler temperatures, autumn is a good time for lawn seeding because it is usually a rainier then too.   I usually see good levels of germination in 10-14 days for the Eco-grass.  This year is working out well (so far).  The soaking rains in early October saturated the soil and I have only needed to add a little additional water to keep the soil moist.

The area between the piles has been (mostly) cleared of stilt grass and is ready for seeding.
I used a leaf rake for this, but a stiff garden rake would have been
more effective for tearing out the stiltgrass plants.
While the standard instructions on the seed bag recommends fertilization at the time of seeding, it is best to do a soil test to determine if added fertilizer is needed.  If you use a mulching mower to return your grass clippings and leaves to the soil your fertilizer needs will be much lower (or non-existent). The risk of over-using fertilizer is that it will stimulate weed growth and that run off of excess nutrients will damage the environment.  Since we are in the Chesapeake watershed I try to use the minimum of fertilizer possible.  That usually means none.  In fact, for the fine fescues fertilization is not recommended.  If fertilization is needed, fall is the best time for cool season grasses.  Spring fertilization will stimulate growth of warm season weeds (and stiltgrass) as well as the cool season grasses.  In the fall only the cool season plants are actively taking up nutrients.

In this full sun area tearing out the stiltgrass exposed a lot of bare ground.
This spot was seeded with the full sun blend.  Just to the back left
 is a full shade area where I planted the Eco-grass mix.

One new thing I learned about tall fescue, Lolium arundinaceum, is that some cultivars are infected with an endophytic fungus that produces loline alkaloids that are toxic to many insects and mammals that feed on the grass.  This endophytic fungus all reduces biodiversity around the infected fescue.  while this is great for the fescue it is bad for the wider plant and animal communities.  The widely used and inexpensive cultivar K-31 has a high rate of infection.  So far I have not been able to find out which cultivar have low infection rates, however this may be more common in southern states.  One way to lower the effects of infected fescue on the environment is to keep it mowed so that it stays in a vegetative state, i.e., not going to seed.  Hopefully its ability to form a good turf and exclude the stiltgrass will outweigh it negative environmental effects.
..