Tuesday, February 17, 2015

Planting Plans for spring 2015

Every year brings another opportunity to grow my native plant collection.  This year I'm focusing on 4 areas:  Clean up and replanting around the swimming pool, clean up and expansion of the meadow, replacing the vinca along the driveway and build up a privacy hedge with the neighbor.  After learning a bit about the current conditions, what is already here and what might be expected to grow here naturally, I've put together a shopping list of natives to get this year.

This moss phlox is pretty happy growing along the pool deck,
A good portion of it is on the concrete slab.
The colors can be intense, so I use mostly one color at a time.
The area around the swimming pool is infested with common evening primrose (Oenothera biennis).  While native, there is just too much of it and it is not that attractive close up.  The soil is mostly a fast draining fill with a moderately high pH (ca. 7.5).  Since this is far from native soil I put a greater focus on what would look good growing in this setting.  Since I had already started using this area for plants native to Texas (my wife's home state) I will be adding two of my favorites, Wine Cups (Callirhoe involucrata) and Indian Blanket (Gaillardia pulchella).   I got some seed on a recent visit to the Wildflower Center.  These will be great for the full sun areas and they tolerate alkaline soils.  The moss phlox could use some bolstering up as well.  I am attempting to remove the English ivy from the enclosure and this phlox seems to be a good candidate to fill back in.

This species of wine cups grows close to the ground, filling gaps around taller plants.
Seed requires a hot water treatment and  30  days cold stratification for germination. 





This is the annual species of Indian blanket, Gaillardia pulchella.


Small's Penstemon is long blooming in shady locations.
The contrasting lavender and white blossoms show up at a distance.



In the shadier areas I will be trying out Greek Valerain (Polemonium reptans aka Jacob's Ladder) and Small's Penstemon (Penstemon smallii).  Despite its common name the valerain is actually a native to the of the US.  This had confused me for a while.  Looks like the name Greek valerain is used for a number of species in the Polemonium genus.  One of them with particularly showy flowers, P. caeruleum, is a European native.  P. reptans grows more like a ground cover

I've ordered some more Indian Pink (Spigelia marilandica) for an area in the pool enclosure with more moisture and organic soils.





This cottonwood seedling appeared in the vegetable garden.
I'll transplant it this spring to a moist part of the new meadow.

I have an area that has been overrun with invasives that I am trying to convert to a meadow.  I cleared half of it last year and hope to finish this spring.  After removing the bad guys I am backfilling with native species.  I realize that I'm making more work for myself by trying to kill off invasivies at the same time as introducing new plantings.  By planting mostly shrubs I think I can more easily manage the area with an annual mowing/whacking of the undesirable plants.  For the right way to convert a weedy area to a meadow or prairie check out this link.

Last year I planted an American plum (Prunus americana) and several elderberries (Sambucus canadensis).  This year I will add some chokecherries (Prunus virginiana) and smooth sumac (Rhus glabra).  I also have a Cottonwood (Populus deltoides) seedling to put on the edge.






The pawpaw blooms in early May,
just before the leaves open up.  

Way in the back I have a large grove of Pawpaw (Asimina triloba) trees.  I've been watching them for 2 years and I have yet to see any fruit.  Since pawpaws produce better with cross-pollination, I will be adding a couple of new individuals to the area,  It is possible that my entire grove is really just one clone.  We'll see if this helps, in a couple of years.




These goldenstar have more than doubled in size after a year in the ground.
I'll get some more to speed up coverage.

In the shady area around the driveway I have been ripping out the vinca and replacing it with shade tolerant natives.  I started with foamflower (Tiarella cordifolia) and Heucheras and these are taking hold.  In addition to these I've seen some really good results with Goldenstar (Chrysogonum virginianum, aka Green and Gold) in open shade areas.  These are relatively easy to find in a regular nursery, sometimes marketed with the plants that you can walk on.  Another plant that I've used in dry shade is big-leaf aster (Eurybia macrophylla), It has dense foliage and spreads by rhizomes so it should do a good job competing with the vinca.


This shiny summer foliage pf aromatic sumac turns red and orange in the fall.
We'll see how it performs in a shadier location.

The boundary between our nearest neighbor is defined with a double row of white pines.  At 40+ years old they are now limbed up fairly high and not providing much screening.  We have already put in a juneberry (Amelanchier canadensis), hazelnut (Corylus americana) and Hoptree (Ptelea trilfoliata).  There was also a pawpaw already there, doing a pretty good job despite the drier conditions.  We are looking to add some additional shrubs to fill in this gap and obscure the view.  A local native plant nursery has listed maple-leaf viburnum (Viburnum acerifolium) for sale this year.  I've been told that this is a very difficult shrub to propagate.  It does well in shady woods so I'm looking forward to trying it here.  I should get two since they don't self pollinate.  I am also looking to get some aromatic sumac (Rhus aromatica).  The wild form grows 5-12 feet, just the right size for our area.  I already have some of the 'Gro-low' cultivar.  At about 3 feet it is a great ground cover shrub for many difficult locations.

Now with may list in hand, I can hardly wait until spring!

Sunday, January 4, 2015

A Winter Walk

Seeing as we were having a spell of dry weather on New Year's day, I decided to take a walk through the woods to see what was happening.  Now that essentially all the leaves are gone there's a whole other world of things to see.  Instead of focusing on the foliage, trees can be recognized by their bark, branching patterns and leaf buds.  On the ground level the few evergreen grasses and perennials are easy to find.  In particular, the evergreen ferns jumped right out.  Following are some photos of plant features that I came across.

The buds of this 2 year old seedling are
smooth and reddish brown.
The first place I checked out were some tree seedlings that I identified in the vegetable garden last summer.  Since I already knew what they were I could learn about how they look in the off season and store that away for future reference.


The end bud of the Sycamore was smooth and pyramidal.  Kind of like those of ash trees, but the sycamore has a single false-end bud (not centered at the absolute end of the twig), while ashes have a terminal bud flanked by two smaller, opposite buds.   

Another tree that sprouted in the garden was an Eastern Cottonwood, Populus deltoides.  Here the bud end is true and the scales are visible.  To me the most notable feature is that the year-old wood looks like it has shrunken back. leaving the stem somewhat squarish with wings, or ridges along the corners. 

Cottonwoods are often considered rather messy trees.  This spring I will transplant it into a moist area of the meadow that I am clearing of invasives.






The  dry leaves on this American beech
make it easy to spot in the woods.

Moving into the woods a young American Beech caught my eye.  In the winter these can be recognized by their tendency to hold onto their leaves until the spring and by their smooth white bark.

Another tree that has smooth white bark is the American Hornbeam, Carpinus caroliniana.  While the beech has a smooth rounded trunk, The hornbeam's trunk is grooved, giving it a muscular or sinewy appearance.  Another way to distinguish these two white-barked trees is their leaf buds.  The buds of the hornbeam are small and dark brown while those of the beech are orangy-brown, long and pointed with many obvious scales.




Another tree with unique bark is the Hackberry.  Though highly variable many trees develop warty knobs and/or ridges that is easy to recognize.  Despite the unappealing name, the hackberry is a valuable wildlife plant, both as a butterfly host species and for producing a crop of 'sugarberries' in the fall for birds and small mammals.
The bark of the Hackberry is hard to miss.

Looking onto the ground plane I found several different evergreen grasses, which remain unknown.  More easily identified were the several species of evergreen ferns.  The most easily ID'ed was the Christmas fern.  This is a common species here growing mostly in shady moist areas.  

Christmas Fern is 'once-cut' and the pinna (leaf)
has a single lobe that makes it look like a boot.




A much smaller fern common here is the Ebony Spleenwort, Asplenium platyneuron.  This one is found in partly sunny location with average moisture.  Mine usually grow to about 6" long and hide in the undergrowth.



The frond of this Evergreen Wood Fern
appears to have been stepped on,
but otherwise looks pretty good.  

While poking around a steeply sloped area I found a fern that was new to me.  Unlike the previous two species this one was much frillier (thrice divided).  I took a bunch of photos and pulled out my fern ID books to come up with a name.  Turns out that I was an Evergreen Wood Fern, Dryopteris intermedia.  This is a common species in the eastern US, but just not that common to my piece of the woods.  It's relatively healthy green appearance in the middle of winter would make it a good addition to a home landscape.


When ID'ing ferns look on the bottom sides of the fronds for the sporangia or sori.
Their shape and location are distinctive for many species.

An unknown fern growing at the base of a tree.


There was one fern that I could not figure out.  It was small (3-4") and had fairly simple leaves (pinna).  It's grow in a gap between roots of a large tree.  I checked the underside of the frond for sporangia, but none to be seen.  I'll need to come back later in the spring to see how it develops.

I would appreciate any ideas on what this might be.


Underside of fronds shows no additional clues.

The last group of plants I checked on were some vines that I planted last summer.  My property is inundated with Japanese honeysuckle.  While I am trying to remove those I am also adding some native ones to fill the voids,  I put in a native Coral Honeysuckle along a fence in the spring.  It quietly grew to a span of over 6'.  Looking forward to seeing some blooms in the spring.  I also added some cultivars, 'Honey Coral' and 'Sulfurea'.  
Can see some flower buds forming on this Coral Honeysuckle.

The leaves of this Carolina Jasmine have turned red,
 but are holding on.

On an impulse I also picked up a Carolina Jasmine cultivar called 'Margarita'.  This species is hardy to zone 7, naturally occuring as far north as southeastern Virginia.  However, this 'Margarita' cultivar is good into zone 6.  So far it is holding onto its leaves.  This one may be too small to bloom come February, but I will be happy if it just survives and starts growing when the weather warms.

Sunday, November 30, 2014

Swags from Nature

It's late November here in Pleasant Valley, MD and most of the leaves are gone.
For the past couple of years we have been going out to the backyard for our holiday decorations.  It's a great time to get the family out to explore nature in the off-season and get a little creative too.  With an impending pre-Thanksgiving snowstorm we moved up our timetable for collecting materials that could be used in holiday swags.

This year we didn't have a lot of colorful berries to use.  One reason is that I have been diligently cutting or removing the invasives like oriental bittersweet, Japanese barberry, winged euonymus and multiflora rose all with colorful fruits that were overly abundent in past years.  The native 'replacements' I've put in, like winterberry holly, chokeberry and smooth sumac, are still maturing. There are still many different textures and evergreens out there that work well together.

Here's what we gathered from around the property.  While it was easy
 to stuff the cuttings into the bag, getting them out without
damaging the delicate seed heads was pretty tricky.
Rather than starting with a preconceived plan for our decorations we just headed out to take cuttings of anything that looked interesting.  The base for most of our swags is some sort of evergreen, so our first stop is to get some pine branches.  You could also use things like yews, holly and rhododendrons.  The broad leaves of the Rhody offer a real contrast in texture from the other smaller leafed plants.

Types of plant material we harvested were:
  • Grasses, provide browns, tans and gold shades, some with interesting seed heads.  Deer tongue grass and little bluestem have a lot of structure to them.  The foxtails are large enough to show up at a distance.
  • Seed heads provide detailed texture.  Monardas, agastache, ironweed, asters, goldenrods, cone flowers and members of the mint family are good examples smaller flowers. The dried heads of larger flowers like annual sunflower, milkweeds, hydrangea and tree peony can really stand out.  Pine cones, of course, are classic wreath material.
  • Berries and Fruits are a great source of color.  Holly berries are a regular addition to winter decorations.  Berries from various Hypericum, roses and beautyberry are some other possibilities.  We also harvested some crabapples for color; although these may not be a good choice for indoors, since they may begin to rot. As I mentioned I have removed many of the brightly colored invasives, like bittersweet and barberry, from our property.  
  • Leaves add a different texture.  This year we were able to get some leafy branches off of the Beech trees.  Some species of oaks also retain leaves that could work well in a swag/wreath.  We also picked up some individual leaves off the ground that had good color in them.  We bundled them in a little sachet, but they could also be used individually.
  • Branches can add a unique structure.  We took some from our winterhazel (Corylopsis) which has a zig-zag stem.  Red twig dogwood would be another good choice having both color and texture; however our plants are are a bit too small to cut back yet.
  • Vines can be used in several ways.  Bundled together they can form the basis for a wreath.  Singly they can add a free flowing element to the design.  Most of the vines we have available are from invasives like oriental bittersweet and Japanese honeysuckle.  We also have some native river grape and Virginia creeper.  I caution you about harvesting the Virginia creeper since, without leaves, it is difficult to distinguish from poison ivy.
When I first started doing this I only wanted to use native species.  But then I decided that I should take this as another opportunity to remove these plants for the property.  I just need to remember to dispose of those plants properly when we take down the decorations.

We covered the table with some large pieces of paper so that the debris could be bundled up more easily.

The basic swag-building tools are clippers, wire cutters (don't use your pruners for cutting wire) and some flexible wire.  I use copper wire for binding together the larger branches and a thinner steel wire to attach the smaller materials.  What I like about swags is that they are so easy to build.  First bind together the thicker stems at one end with some wire. This creates a bundle of stems that form the base or background.  Then layer other materials on top of the base, tying them in with wire.  More details can be added as desired.  You can also push single stems into the bundle as accents, the tightness of the bundle will usually hold them in place. Finally tie in a loop of wire at the main bundle to use as a hanger.

The swags you create can be simple with just a few different materials, or more elaborate with a variety of shades and textures.  Here are some photos of what we made this year:

Here we started with a bundle of white pine and attached a wide variety
 of seed heads on top, such as virgin's bower (Clematis virginiana),
garden phlox, tree peony, annual sunflower (at top) and various grasses.
  To finish we tied in a wide branch of beech to the back.

This one used the same technique, but fewer materials.
Here there are a variety of grasses including deer tongue grass
and purpletop, on top of the bundle of pine branches.
At the tie off point there is a small bundle of maple leaves and some rose hips
Here, some of the branches point up, others down.
Also a rhododendron branch in the center changes the texture of the swag.   
These next two were constructed by my sister using a lighter touch.

Here she created a circular wreath using Japanese honeysuckle.
Then she tied in a little bundle of of beech leaves, foxtails,
cone flowers on a base of white pine.
Since we had so much interesting material left over my wife suggested putting it into a pot.  This was so easy to put together.  To help things to stand up better I put a 6" short log in the center, then wedged the branches between it and the pot.

Here we put in some of the left overs including some Corylopsis branches,
 a wild mint, spotted beebalm, a wild onion and rhododendron branches.
When the holidays are over most to these can be put into the composting, after removing the wire bindings.  I will separate any fruits or seeds from the invasive plants that were used (oriental bittersweet and multiflora rose, in these examples) and put them in the trash to keep them from spreading.

We had a great time making our natural decorations.  Hope you all have a great holiday season!!


Wednesday, November 19, 2014

Fall Grasses

We've had a long and relatively mild fall here, that is until this week when overnight temps got to the low 20's.  Many trees held onto their leaves for a long time wait for a real cold snap to trigger leaf drop.  The Fothergilla I planted last season finally turned the fluorescent orange that I was hoping for.

As the temperature dropped the leaves of this
 Fothergilla 'Mt. Airy' changed to this intense orange color.
It got me thinking about my plant selection.  I am always looking out for plants with exciting fall foliage, reds, golds and oranges.  It got me to thinking that these are more effective when contrasted with cooler or muted colors like pale yellow, green or tan.

One class of plants to fill that role are the native grasses. Late or warm season grasses that produce flowers and seeds in the fall are particularly effective.  The low angle of the sun late in the year really plays off the seed stalks, bringing them to life.  I usually leave these stalks standing through the winter to get the most out of them.  I'll clean up what remains in the spring.

Another benefit of these grasses is as a food source for birds and as shelter for many insects and overwintering animals.



Here are some of the grasses I have that are showing off nicely this fall.

I have planted inland sea oats (Chasmanthium latifolium), aka, Northern sea oats and several other names, along a sloping area by the house subject to erosion.  This grass produces a dense fiberous root system that holds the soil well.  While its native habitat is in moist shady locations it will also tolerate dry shade.  It sprouts early in the spring and can spread, both by expanding clumps and seeds, to form dense stands.

The broad leaves of Inland Sea Oats has a bamboo-like appearance.
These copper colored seeds will persist into winter.



The plan is for this Pink Muhly to fill in along this fence.
When they open the flowers look like exploding fireworks.
Another grass that I have added to the property is Pink Muhly Grass (Muhlenbergia capillaris).  This species is native to the eastern US and the gulf coast, but you're not likely to find it naturally in the mountain regions where I am.  The reason I put this in was the light-catching effect of the flower plumes.  At first I was concerned that this effect would not be strong because I didn't have a good angle for the backlighting. But that's not a problem.  The photo above was taken at 2 PM and there is penty of light being scattered by the flowers even though the sun is still rather high in the sky.

I've found this plant to be slow to establish here. Some of that has to do with competition from the surronding plants. Clumps of pink muhly will expand, but it is not an aggressive spreader.  Larger masses should be mown or burned back in late winter to clean up the clump.




This clump of little bluestem is easily identified
by the silvery seed tufts along the stem..

These next three species are growing wild around my home.  Little Bluestem (Schizachyrium scoparium) is a common native species around here.  It is well suited to dry sunny sites.  It grows well in poor soils.  In excessively rich soils it puts on too much growth and flops over.  As a warm season grass it grows to 2-3 feet by mid-summer.  In the fall it turns golden and produces fuzzy white seeds along the upper stem.  These catch the light and envelop the stem in a silvery glow.  Some selections of little bluestem take on redder shades in the fall.   Small birds feed on the seeds, so I leave these up all winter.



One of the more distinctive grasses I have is Deer-tongue grass (Dichanthelim clandestinum, formerly Panicum clandestinum).  It has relatively broad leaves compared to other grasses.  It is a cool season grass, producing terminal spikelets in early to mid-summer.  Unlike most other cool season grasses, branching and growth continues through the summer.  The name, deer-tongue grass, refers to the shape of the inch-wide leaves, not to any preference for deer to eat it.




Deer-tongue grass persists well into fall, here as a deeply textured mass.
No longer colored, the seeds of Purpletop still catch the light.

Another common pasture grass here is purpletop (Tridens flavus).  When it first blooms in late summer it has a reddish purple color.  When distributed through a field, these blooms cast a purplish haze over the scene.  As the seeds mature the color is lost and the seed stalk becomes a brownish-gold.  As a pasture grass it is very palitable to livestock.  It is also a larval host to a variety of butterflies.

I have not seen purpletop used in any designed plantings, though it does have some interesting features.  The red colored flowers are best appreciated en masse and at a distance.  What might be useful in a smaller garden is to use the 3-4 foot tall flower stalks as a translucent screen between plantings.  Since the leaf blades are concentrated in the lower half of the plant they would not block a view across a planting.  Purpletop grows well on dryish soils in part to full sunlight.

Wednesday, October 29, 2014

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.







Saturday, October 18, 2014

Making a Plan to manage Japanese Stiltgrass


My wife and I have been on a campaign against invasive plants on our property.  Our two main targets are garlic mustard and Japanese stiltgrass, Microstegium vimineum.  The spring time is when our focus is on garlic mustard, when the ground is soft and before it begins to flower.  In late summer our focus switches to stiltgrass.  I am trying to come up with a program that works for me: how can we eliminate as much stiltgrass with the least amount of work and without causing too much collateral damage. 

This is a shady area that used to be mowed.  The stilt grass has moved into
the gaps and is crowding out the native vegetation.
We've been pulling plants from planting beds as they appear (compulsive behavior), pulling larger plants and weed whacking in late summer.  Recently a friend pointed out how much stiltgrass was growing in the lawn.  I realized that this lawn weed may be creating a large mass of seed that could easily recontaminate the surrounding woodlands.  So I'm now including the lawn in the project. 

The Plan

As the weather has gotten cooler I could see how stiltgrass has taken over large swaths of the lawn.  This effectively creates bare spots that are prime territory for stiltgrass to resprout in the spring.  Remembering that one of the best to control lawn weeds is to have a thick turf, I decided that I should be more aggressive about filling in those bare spots with desirable plants. My general plan is as follows:
  • Pull in early August.  This allows a second crop to germinate, but not enough time to mature before frost.
  • In natural areas minimize disturbance to soil and encourage existing native species.  Cut stiltgrass low when flowering starts, about mid to late August to early September.
  • In disturbed areas (lawn) try to add more competitive ground covers, like cool season grasses to get established before stiltgrass germinates in mid-April (WVa).  
This will be a 5+ year program to get rid of the current crop of seeds already in the ground.  There will be continued outside pressure from surrounding areas infested with stiltgrass. 

Japanese stiltgrass is turning brown in the lawn early October.
This thatch can be slow to break down,
leaving a gap for more to germinate in spring.

In late fall and winter stiltgrass appears as a persistent golden-brown thatch.  The usual invasion route is into areas of disturbance in an otherwise natural space.  Deer are also vectors for the spread of stilt grass.  They often bed on top of stiltgrass infested areas, then carry the seed with them, dropping it along their paths.  While they will sleep on stiltgrass, deer do not feed on it.  Instead they feed on native vegetation, further helping stiltgrass to outcompete native species.

In late August/early September a flush of growth is a signal that stiltgrass is maturing and seed production is about to commence.  Waiting to cut the grass at this time does the maximum damage to its reproductive cycle.  Early season mowing or whacking of stiltgrass stimulates early flowering and a lower, harder to remove growth habit.  Pulling stiltgrass early in the season creates openings that allows additional germination.  By waiting until late in the season these late germinated seedlings will not have time to mature before they are killed by the colder temperatures. I really like the idea of tricking it into germinating late in the season.  Also plants pulled out before the seed has matured can be left to decompose.  After the seed has ripened in mid- to late-September plants should be bagged and landfilled to prevent spreading of the seed.

I found this recommendation by West Virginia forester, RussAnderson:
"If the area where stiltgrass control is desired includes a lawn that is infested, all regular mowing of that portion of the lawn should cease around July 15 and allowed to grow for a month before mowing again. Normally, during this 30 day period the stiltgrass will significantly  outgrow all other lawn cover making it both easier to identify and easier to kill. To ensure the highest proportion kill possible in the stiltgrass the best option is to mow the lawn, especially where the stiltgrass is present at the lowest blade setting. Completing the mowing during the hottest and driest conditions possible will further enhance the kill in the stiltgrass. If the mowing of the lawn is successful, regular lawn grass will begin to fill in the dead spots almost immediately. If the stiltgrass is mowed before it is allowed to go to seed the number of stiltgrass seedlings on the lawn will greatly decline in succeeding years."

It's hard to leave an area of lawn unmown.  But if this works, consider all the labor and chemicals saved compared to removing stiltgrass by other means.  Also this can be a positive step by NOT doing something (mowing for a month), rather than continually mowing. 

Here's that same shady area after weed whacking and raking up the cut stiltgrass (upper left).
Pink flags indicate the location of desired native species left in place.

Weed whacking stiltgrass from hard to mow areas should be done in this late August period.  Cutting as low as possible removes both the upper flowers as well as the lower cleistogamous flowers hidden in the stems.  If there are native species going to seed in the area, waiting until they mature can help reestablish native populations.  In some smaller areas I surveyed for native species and flagged them so that they could be avoided while whacking the stiltgrass.  

Cool season turfgrasses

Since each fescue plant is so small the seeding rate
 is fairly high, 5 lb/1000sf, to get good coverage.
Tall fescue is a good choice for high traffic sunny areas, but this is not a North American species.  Since my focus is on using native vegetation and natural appearance, I am using a mostly native fine fescue blend. (Eco-grass from Prairie Moon) of red and creeping fescues for the shadier areas.  In the wilder areas I am trying a blend of native grass species.  This is an experiment to see if I can get good cover with these prairie species used in a lawn-like environment.  However, a prairie is managed much differently than a lawn and there is a good chance that this approach will not be successful.  Many of these native grasses need a year or two to put down roots before top growth takes off.  Ideally these species should be allowed to mature for a season or two before they get chopped back, by mowing or grazing.

For sowing, I first used an iron rake to clear out the stiltgrass thatch.  (Looking back, if had done this in early September I could have limited the stiltgrass seed production even more.)  This also loosened the soil surface.  Then I broadcasted the seed.  Finally I used the flat edge of the rake to push the seed in closer contact with the soil.  To get good germination and establishment of the seedlings the ground should be kept moist.  I usually try to time fall seeding with the weather forecast to take advantage of rainfall to get the grass started.

About 10 days after seeding with Eco Grass a fine green haze is covering this previously barren area.
Most commercial turf grass blends contain annual and perennial ryes which are fast growing and fill in quickly.  The fine fescues used here do not grow as quickly and it will take longer to have that full look.

Native Grasses

With that in mind I decided to try this as an experiment.  I selected species that tolerate grazing, where they would be eaten back to 3-5 inches, since mowing it is a similar action.  Since I am fall sowing I selected mostly cool season grasses, with the hope that they will get established before the stiltgrass germinates in the spring.  Also, there are warm season species in the mixture to try and fill in the gaps when the weather warms.  The grasses I selected where mostly native to Maryland or the mid-Atlantic region.

Name
Botanical Name
Season
Exposure
Seeds/pound
Sun mix ratio
Shade mix ratio
Canada rye
Elymus virginicus
cool
Part
100K
8
4
Virginia rye
Elymus canadensis
cool
Part
100K
4
2
Side Oats Grama
Bouteloua curtipendula
warm
Full
150K
6
1
June Grass
Koeleria macrantha
cool
Full
2000K
1
0
Fall or Beaked Panicgrass
Panicum anceps
warm
Part
--
0
1
White clover
Dalea candida
--
Full
260K
4
0









I made up two seed blends one for full sun and the other for part shade.  The majority of the seeds are cool season grasses.  The weight ratios for each are listed in the table above.  When making up a seed blend you need to account for the number of seed per pound and the seed viability, usually listed as pure live seed (PLS) which is seed purity times the germination rate.  This is my first time trying this so I can't be sure that it will work.  I did put some seed into a new meadow area that will not be mowed regularly.  This will serve as my 'control' group.

A better way to sow these native grass seed would be to use a seed drill and put them in 1/4 to 1/2 inch deep.  Instead, I sowed them the same as I did for the fine fescue, but at a much lower rate (pounds/sf).  The recommended rate for Eco Grass is 5 lbs/1,000 sf while for Canada rye it is on the order of 3 oz/1,000 sf.  Since the ryes and other native grasses are much larger plants when mature, compared to a single fescue plant, it takes only a few seeds to get the same coverage.

June grass has a seed similar fescue is size;
however, the resulting plant is much larger

Side oats grama has a lot of husks included, but
these are accounted for in the PLS calculation  

Virginia and Canada ryes look similar.  


If I don't see sufficient germination by next spring I will go back to a standard turf grass blend.  It's better to fill in with something than leave space for stiltgrass.

15 days after seeding I'm seeing some new grass growth in some of the sunnier areas.
The shade areas are not showing definitive signs of new grasses.


We were surprised to find this obedient plant
blooming late in the season.  I don't know if this is indigenous
 or if it escaped from an earlier planting by a previous landowner.

Other strategies

Broad spectrum (glyphosphate) and grass specific herbicides are effective on stiltgrass, but they may impact surrounding vegetation.  I found a mention of using a dilute solution of Fusion® (grass specific herbicide) to kill stiltgrass with relatively little collateral damage to native perennials and grasses.  Another tool is the use a preemergent herbicide in spring.  However, since stiltgrass continues to germinate throughout the spring and summer, a single treatment alone would not be effective.  A preemergent would also suppress germination of other desired species.


One of the side benefits while pulling stiltgrass is that it gets you looking closely at plants and nature.  We've spotted a number of interesting plants this year while thinning out the overgrown edges of the woodlands.  Most recently I spotted a dark pink Obedient Plant among the grasses.

References

The following are some additional websites with useful information on dealing with Japanese stiltgrass: