Monday, March 26, 2018

The Forsythia are in bloom, now it's time to...

The blooming of Forsythia is a signal to begin a number of outdoor tasks.  It signals a good time to apply preemergent herbicides for control of summer annual weeds.  I'm giving this a go this year as another tool to get rid of Japanese stiltgrass, Mircostegium vimineum, from my property.  I've been making progress in the woods where I have been pulling it out in July and August as it is getting tall.  Getting it out of the lawn is another matter.  

It's the end of March, and although the Forsythia started blooming
at first in January, I think they are doing it for real now.
There, repeated mowings keep it short and actually induce early seed formation in the lower stems.  I have been raking/combing it out of the lawn in a few areas but that does not seem very effective.  It seems that while I remove a lot of the weed, any remaining stiltgrass just expands to fill in the gaps.  So while I prefer to avoid the used of synthetics, I've tried going it alone for a couple of years and now I need some help.  

Many of the common preemergent herbicides used for crab grass control have been found to be effective on stiltgrass when applied prior to seed germination.  Preemergents that have been shown to be effective include Dithiopyr ('Dimension'), Pendamethalin ('Pendulum'), Prodiamine ('Halts') and Trifluralin ('Preen Weed Preventer').  One of the challenges is finding a preemergent that does not come with added fertilizer.  In my case I do fertilization in the fall, since I am growing mostly cool season grasses, particularly fine fescues, Festuca rubra cultivars.  Fine fescues have low fertilizer demand and I see no good reason to apply fertilizer at a time when weeds are about to take off. The product I found contained only Dithopyr, no excess fertilizer.

Hairy Cress is a winter annual weed that has been taking over here.  Last year I mowed
it early before much of it started producing seed.  This year I'm hoping
 to get some added help from the preemergent herbicide.

As an added bonus this may help control the hairy bittercress, Cardamine hirsuta, that is growing in the lawn.  This weed is a winter annual, sprouting in fall and again in early spring.  While it dies back by mid-spring, this creates gaps in the turf that provides space for the stiltgrass to fill in. 

Dithopyr works by interfering with development of new roots, after seeds have germinated.  Perhaps I should have waited a little longer to put this down in order to allow the existing grasses to get further along, but I didn't want to forget. We'll see how all this works out later in the summer when I can compare treated and non-treat areas for amount of stiltgrass.  Check out this earlier post for some things I tried last fall. 

Sunday, January 28, 2018

Replacements for Nandina and other learnings

Recently I wrote an article for Houzz on plants to use instead of Nandina domestica, aka Heavenly Bamboo or Sacred Bamboo.  This overused Asian species is adaptable to a wide range of growing conditions in USDA zones 7-9 and has reached invasive status in the Southeastern US.  In Maryland it is listed as a Tier 2 invasive plant meaning that, while it can still be sold in Maryland, it must be accompanied by signage stating that this is problematic species. 

In addition to its invasive characteristics, the bright red berries so prominent in winter are actually quite toxic to over-wintering birds.  The cedar waxwing is particularly susceptible due to their feeding behavior.  Blue Jays and Mocking birds are examples of other species that are at risk from this shrub.

You can read more about the toxicity of Nandina berries to birds in this post from Audubon Arkansas. You can mitigate this problem somewhat by planting more plants that bear fruit late in the season, particularly native species; but, you should not consider Nandinas as wildlife-friendly plants. If you want to use Nandinas for aesthetic purposes consider cultivars that do not produce berries such as 'Nana', 'Nana Purpurea', 'Atropurpurea Nana', or 'Gulf Stream.' These non-bearing cultivars are also less likely to spread outside the garden.

One of the species that I recommended in this article is Oregon Grape, Mahonia aquifolium, and other members of the genus.  This broadleaf evergreen shrub is native to the Pacific Northwest, but is also found growing wild in some eastern states, most likely as a garden escapee.  I thought I had some growing in my backyard, too.  While researching this species I discovered that what I had was, in fact, Mahonia bealei, Leatherleaf Mahonia.  This species, originally from western China, is listed as invasive in many of the same states as Nandina.   

Here are two Leathrleaf Mahonia growing in a clump in late January. 
This species of shrub typically grows 4-10' in height,
compared to 3-6' for the Northwest native Oregon grape.
The bright yellow flowers of Leatherleaf Mahonia bloom in late winter to early spring
on clusters of terminal racemes.  This species can be distinguished from Oregon Grape,
M. aquifolium, by the number of leaflets, 9-15 vs. 5-9, for Oregon grape. 
Also the leaf color of leatherleaf mahonia is a dull bluish green compared to
the shinier dark green leaves of Oregon grape.

Learning that what I thought was Oregon Grape was actually a non-native species with invasive tendencies, I've decided to replace it with species native to this area.  Even before this revelation I was considering replacing it with a more appropriate East Coast species.  I would like to have an evergreen shrub that likes moist soils and open shade.  Looking at my list of Nandina replacements for inspiration, I think I will go with Inkberry Holly, Ilex glabra, as the replacement. As with most hollies I will need both a male and a female plant to get berries for the birds.  Fortunately there are both male and female cultivars available in the nursery trade so I will be able to start an inkberry family without too much trouble.  As the male I will go with 'Nordic', a fairly compact species.  There are more choices for the female.  I would like them to grow to about 6 feet, so I have a choice of 'Compacta', 'Densa' or 'Nigra'.

This inkberry is part of a new parking lot planting at a local library
that features mostly native species.  It does well in part to full sunlight. 
My site may be on the shady side, but that may encourage
a more open form that I would like for my particular application.

Wednesday, January 10, 2018

Using Bare Root Plants

Over the 5 years or so that I've been here in Pleasant Valley (Zone 6b) I've been augmenting our grounds with more native species.  In order to get some of the species I wanted I've been getting more bare root plants than in the past.  What I like about them is that you can find many species that are not available in containers and that they are much less expensive, averaging about 1/3 the cost of the same plant in a container.  This lower cost is due in part to the lower costs of shipping, only the plant without the soil, and to lower production costs at the supplier.  The down side is that these plants are only available when they are dormant and that they need to be planted while it is still pretty chilly out, either in late fall or very early spring. So right now (January) is a great time to get in an order, in time for early spring planting.

I've had mixed success with these bare root plants.  Reasons for failure include not planting them in the right place, competition from existing plantings, deer browsing and some poor technique.   I won't go into the steps of planting bare root plants, they often come with detailed care and planting instructions.  You can also find instructions on the web. 

Here are some things I've learned from my experiences:

Get plants in the ground quickly.  If possible get them in the ground within a day or two of when they arrive.  While you can keep them in cool storage for a time as long as the roots stay moist, or you can heel them in, by laying them in a shallow hole and covering the roots with moist soil.  I seem to be having better results with plants that I put in place quickly.  It is important to get plants in the ground while they are still dormant.  This way roots can get in good contact with the soil before the buds open and put a greater stress on the plant.  I have planted bare root stock in both late fall and early spring.

This Canaan fir has been in the ground for about 2.5 years. 
It started at about 6 inches.  The chicken wire and steel posts help
protect it from male deer who will rub off the branches
as they clean their antlers.
Get good soil contact with the roots.  When planting in the garden make sure that soil is well packed around the roots and spread the roots out in the hole as you layer in the soil.  What I have been doing lately is carefully spreading out the roots as I have been adding in the soil.  After about half of the hole is filled I fill the hole with water and let it settle.  This removes air pockets and improves soil contact with the roots.  I continue to fill in around the plant with soil, continuing to spread out the roots, followed by another through watering. 

Plants in pots need time to develop a good root system.  For bare root plants that I haven't had time to plant, I've potted up with container mix, watered them well and left them in a cool protected location.  Only about half of the plants survive until the weather warms up.  Not a particularly good record.  The survival rate of these potted up plants after transplanting has not been great either.  What I believe to be happening is that the roots have not had a chance to develop while in the pot and there is too much damage done to these weak roots when they are transplanted into the garden.  I've had better success with plants that I've allowed to grow in the pot for a full season before going out in the yard.

Protect plants from critters and competition.  I've lost a number of young plants to deer browse, so now I put a little chicken wire cage around most of my new plants.  I've also lost a number that have been shaded out by surrounding vegetation.  When planting in mid-fall or early spring it is not obvious how much crowding there will be come June and July.  I need to remember that these are still little plants and they are easily over-shadowed by larger established vegetation.  Like any new plant, bare root plants need extra water while they are getting established.  I also tie a fluorescent pink ribbon around each new plant so that I can locate them more easily when clearing out the competition.

Close examination of this Juneberry shows that the leaf buds
are still plump and healthy looking.  A good sign
that it will survive the winter.  The pink ribbon helps me keep
track of these new additions in the landscape.

Here are some of the species I've worked with:
Here is the Twinleaf in bloom.  This is one of the first bare root plants
I put in.  It's now 4 years old.

Perennials:  Celendine poppy (Stylophorum diphyllum), Christmas fern (Polystichum acrostichoides), Merrybells (Uvularia sessilifolia), Twin leaf (Jeffersonia diphylla),and Jack in the Pulpit (Arisaema triphyllum) have performed quite well.   Mayapple (Podophylum peltatum) and  Large-flowered bellwort (Uvularia grandifolium) are in dryish soils and have been struggling.  The wild ginger (Asarum canadense) was planted in a very challenging location, under an English walnut and surrounded by vinca, and has faded away. Alleghany pachysandra (Pachysandra procumbens) was planted in November in a dry shady location, so we'll see how that works.

Shrubs:  Black chokeberry (Aronia melanocarpa),  Gray dogwood (Cornus racemosa),  American hazelnut (Corylus americana), Witchhazel (Hamamelis virginiana), Spicebush (Lindera benzoin),  Chokecherry (Prunus virginiana),  Smooth sumac (Rhus glabra), Red elderberry (Sambucus pubens),  and Meadowsweet (Spiraea alba v. latifolia).  The meadowsweet and hazelnuts have been the most successful at getting established.  Smooth sumac has suffered from both deer browse and being over shadowed by other aggressive plants.  The red elderberries and witchhazel which did not make it were in very shady spots.  The chokecherries were potted up when they got here and only 2 of the 6 survived.  Those 2 were planted out 3 months later.  Soon we'll see how they made it through their first winter.   

This American hazelnut has been in the ground
for about a year now.  In the inset you can see the swollen leaf bud
that indicates that this branch is still alive.

Trees:   Canaan fir (Abies balsamea v. phanerolepis),  Concolor fir (Abies concolor),  Juneberry (Amelanchier canadensis),  Redbud (Cercis canadensis), Red cedar (Juniperus virginiana), Tupelo (Nyssa sylvatica),  Virginia pine (Pinus virginiana), American plum (Prunus americana), and  Douglas fir (Pseudotsuga menziesii) .   The best performers of this group are the tupelo and the Douglas and Canaan firs.  Ones that have not worked out here are the Virginia pine (wrong soil type here), Redbud (location had too much shade from competition), Red cedar  and  the Concolor fir (uncertain).  The American plum was just planted this fall, so the jury is out, but they look OK so far. 

Thursday, October 5, 2017

Progress on Japanese Stiltgrass Removal - 2017

My 4 year long battle with Japanese stiltgrass, Microstegium vimineum, is continuing and it must be a continuing fight to remove this invasive grass from my property.  Since this is an annual grass the goals are to keep it from producing a new crop of seed and to eventually deplete the seed bank so that it won't crop up again from older seed.  Since this grass is all around I will need to take the fight to the neighborhood and beyond.  This will be easier if I can demonstrate to  other that this is a battle that is worth fighting.

One approach to Japanese stiltgrass removal is to nuke the site with round-up or a grass selective herbicide.  Despite it being effective on the current year's growth, this would still be a multiyear approach to deplete the seed bank.  I'd rather not kill everything because I have a number of interesting plants that I want to keep and I am generally opposed to the indiscriminate use of herbicides or pesticides. 

The key to non-toxic approach to stiltgrass removal is good timing.  Pulling the grass in late summer as the flowers are forming (late July to early September in Maryland) is the best time to concentrate your efforts.  Early season pulling helps, but if some plants remain they will expand to fill the void and you will need to return to pull again.  Stiltgrass pulled before seed has formed can be composted, though I usually segregate it from the rest of my garden scraps just in case.   Any grass pulled after flowering should be bagged or at least segregated and covered so that seed can not escape.
Here's a woodland edge area in 2013 when I started pulling/whacking stiltgrass
In 2014 coverage is not as dense, but still dominant.
In 2015 other plants are showing up.  Also I had seeded in some Virginia rye in 2014.
Now in 2017 stiltgrass is no longer dominant.  In the foreground is
Virginia rye, Elymus virginicus, drying out after seeds have matured.  

 The photos above show the progress that has been made over 4 years.  For the first two years this site was weed whacked to near ground level and then raked out.  As the stiltgrass density dropped I switched over to hand raking and pulling for the past two years.  These methods were more selective and allowed me to avoid the more desirable plants that were coming back in.

Mature Japanese stiltgrass, note the
location of the cleistogamous flowers.
In lawns, mowing stiltgrass is done to control its spread.  Unfortunately stilt grass has the ability to form cleistogamous flowers near the base of the stem.  These flowers are enclosed in a leaf sheath about an inch off the ground and can survive most mowings.  It has been reported that these flowers mature earlier in stiltgrass in regularly mown lawns.  To address this Russ Anderson, a West Virginia forester has suggested allowing stiltgrass to grow freely through July and then mow it closely to the ground in August as the flowers begin to develop.  The expectation is that there will be fewer cleistogamous flowers and by cutting it back late in the season there is not time enough for the grass to regrow.  I have been doing a variation of this in an isolated area where I am growing fine fescue.  Instead of mowing, I use a manual grass whip.  This rips out the stiltgrass and leaves more of the fine straight blades of the fescue intact.  After doing this for two years the amount of stiltgrass in the area has decreased, but I still have a few years to go.  

Another technique that I have been using  to remove stiltgrass from the lawn is to briskly rake the lawn after a rain to try and catch the lateral stems (stolons) of the stiltgrass.  Using a spring or bamboo rake does tear out a lot of stiltgrass, but it also tears up the soil and can damage the bunch and perennial grasses as well.  I also found that after doing this in early July, even though I removed a great deal of stiltgrass, much of it had regrown to fill the gaps in the lawn.  Inspection of the stiltgrass at this time did not show evidence of the cleistigomous flowers. 

This area was raked over with a steel garden rake.  Nearly all this debris is stiltgrass.

What appears to have worked better is a stiff steel garden or bow rake that is pulled along the surface of the ground.  It catches and pulls out the stolons of the stiltgrass and since the action is not so vigorous, most of the other bunching grass are left intact.  I did this in mid-September so there is not enough time for the stiltgrass to regrow.  Even though the soil was dry, the stiltgrass pulled out easily.  Inspection of the stems showed that there were some cleistogamous flowers forming at this time.

Areas that are blackened were burned with the torch (next to watering can). 
I kept a full watering can nearby just in case the fire got out of hand (it didn't).  I left a small area
in the middle un-burned as a 'control group'.
These mechanical methods are helping reduce the number of stiltgrass plants in the lawn but there are still a number that escape the raking and pulling.  A new approach that I am trying out this year is fire.  Burning stands of stiltgrass is not effective early in the season while new plants are still germinating, or in the off season when plants are already dead (stiltgrass seed is relatively fire resistant).  However, burning in late summer as the stiltgrass is beginning to flower may be a way to successfully battle a stiltgrass invasion.  This method was suggested to me by Joene Hendry, who writes the blog  Joene's Garden.  The process I am trying is to first mow the area close to the ground (about an inch), then allow a day or two for the grass to dry out.  Next use a garden torch to burn the remaining stems, this should get at those hidden flowers.  While this may seem extreme, any perennial  grasses with good root systems will bounce back in a week or two, but the stiltgass is not able to recover.   I did try burning without mowing first, but stiltgrass holds a lot of moisture and it takes a long time to completely burn up such a moist plant.  Mown plants, without a lot of leaves, were quickly burned up.

Another element of stiltgrass removal is to fill in the gaps with desirable vegetation.  Since I am located in the cool season grass zone I have been using a fine fescue blend (like Eco-lawn) in the shadier areas and tall fescue blends in the sunnier spots.  I do have some zoysia grass growing in the sunnier spots.  This warm season grass grows thickly and excludes most of the stiltgrass.  It's unfortunate that there are not more native options for turf in this area (although red fescue, Festuca rubra, is technically a native species).  By avoiding the use of broad spectrum herbicides I do allow the native sedges, violets and other species a chance to repopulate.

I did get an early start over-seeding this fall and I hope to have the new plants established before it gets too cold.  If these desired grasses get established I will experiment with some pre-emergent herbicides.  These act by  interfering with root development after seed germination.  These are particularly effective on annual species such as Japanese stiltgrass and crabgrass.   I imagine a year without stiltgrass competition should help develop a thicker lawn. 

Saturday, July 1, 2017

Red, White and Blue for the Fourth and other times, too

Happy Fourth Of July!  When I think of the 4th it's all about red, white and blue.  In the garden these colors are not usually used together, unless you are doing a theme planting or a flower arrangement.  Occasionally it happens, though, by accident.

This mostly native arrangement has 'Annabelle' Hydrangea for white,
Monarda didyma and non-native Salvia splendens for red, and the blue
 is supplied by Campanulastrum americana and Salvia farinacea 'Victoria blue'.
The green fireworks are bottlebrush grass, Elymus hystrix.
While I didn't plan this color scheme, this combination of
blue flag iris, Iris versicolor, and the red and white striped flowers
of myrtle-leaf mountain laurel, Kalmia latifolia 'Minuet'
made a pretty nice display in late May. 
Here are some North American native plants that can supply you with red white and blue flowers for each season of the year.

Scarlet sage is not hardy here so I grow it as an annual.
However, its seed will overwinter with a little protection
 In picking out these plants I looked for true reds rather than the many pinks and purples that are out there.  Roughly in the order of bloom from spring to fall  there is red trillium (Trillium erectum), wild columbine (Aquilegia canadensis), Indian pinks (Spegelia marilandica), fire pink (Silene virginica), red beebalm (Monarda didyma), various red salvias (Salvia ssp.), standing sypress (Ipomopsis rubra), turkscap (Malvaviscus arboreus), scarlet  rosemallow (Hibiscus coccineus) and cardinal flower (Lobelia cardinalis).
Cardinal flower makes a strong statement in late summer in sunny moist locations
The pure white flowers of bloodroot are one
of my favorites in early spring.
There seems to always be something white in bloom. Here are 10 native plants with white flowers roughly in order of appearance:  Bloodroot (Sanguinaria canadensis), Phlox (all species have some white forms blooming from early spring to late summer), beardtongue (Penstemon digitalis), elderberry (Sambucus canadensis), hydrangea (H. arborescens and quercifolia), summersweet (Clethra alnifolia), swamp rosemallow (Hibiscus moscheutos, often with a scarlet center), tall snakeroot (Ageratina altissima), white turtlehead (Chelone glabra) and various asters.
Elderberry has large flat flower clusters
for nearly a month in late spring.

There are also native blue flowers throughout the growing season.  These plants tend to prefer shady locations.  Also their blue flowers show better in part shade than they do in full sun.  Many of the blues tend toward lavender or purple, I've tried to select more mid-range blues.  Here are a few, again in order of bloom:
Virginia bluebells carpet moist ground in early spring.
Virginia bluebells (Mertensia virginica), Jacob's ladder (Polemonium reptans), Ohio spiderwort (Tradescantia ohioensis), blue flag iris (Iris virginiana), American bellflower (Campanulastrum americanum), gayfeather (Liatris spp.), mealycup sage (Salvia farinacea), blue mistflower (Conoclinum coelestinum), great blue lobelia (Lobelia siphilitica) and various blue asters.

This smooth aster is one of the bluer (less purple) native asters in the eastern US.
(Should be Syphyotrichum laeve, sorry)

There are many other red, white and blue blooming natives out there and I would appreciate hearing what your favorites are.  And again, Happy 4th!!!

Tuesday, June 20, 2017

Building a Container Water Garden

One of the challenges to creating a pollinator friendly garden is to include a water source.  We have a few static birdbaths, but ours are out of the way and often ignored.  To prevent mosquito breeding in these still ponds we throw in a 'mosquito dunk' which kill their larvae.  Having visited a few gardens with elaborate water gardens I was inspired to bring those home, in a scaled down version.

The finished product 2 days after completion.
What I have assembled is a container water garden that sits on our deck in easy view of the front door.  While I really wanted to include a lotus, they require a lot more space (min. 6 sq.ft.) to do well.  Instead I found a miniature water lily with 3" leaves that are in good scale with my container.  For a vertical element I chose squarestem spikerush, a native species that grows to 2' tall.  Anything taller would be out of scale.

Let me run you through the features of this container garden and the steps to build it.  The tub itself is a plastic planter bought from Costco for under $20.  The top is 2' in diameter and it holds about 20 gal. of water.  The depth is 15-18" which allow for the lily to be about a foot under water.  The bluestone rocks are partly for decoration but some are porous enough to be a butterfly watering station.  The rocks are stacked to create a small waterfall, powered by a small fountain pump.  For this sized tub, 20 ghp is sufficient. Since waterlilies do not like moving water the waterfall is directed to the side and into the rushes to slow the flow to a ripple.  The reason for the waterfall is to add a sound element to the garden and to create enough flow to keep mosquitoes from breeding in the otherwise still water.

The steps for constructing this garden are pretty easy.  Here the parts I used are shown.  They include the container, this one is plastic but a galvanized metal tub would work as well. There are also a small submersible pump, a timer, and about 3' of flexible hose to route water for the waterfall.  The concrete blocks create a flat base for the plant pots and the decorative stones.  Since I wanted a waterfall, at least one of these stones is concave to channel the water.

The 'hardware' for the water garden.

Next there are the plants.  We are fortunate to live not too far from Lilypons Water Gardens in Adamstown, MD.  They have been in business for a 100 years supplying water garden plants, fish and supplies.  There I was able to get some advice and select plants appropriate to my needs.  Since my container only has about 3 sq. ft. of surface I needed to look at smaller sized plants.  I selected the 'Helvola' hardy waterlily, with its smaller leaves and flowers it would not look at all crowed in my small container.

Here I measured the length of the stems so that
 I could place the pot at the proper depth in the container.
Turned out the setting directly on the bottom
 was the perfect spot.

Here's the square-stemmed spikerush.  The stems have a
flat membrane at each corner that catches the light.

Here I used the concrete blocks to elevate
 the spikerush so that it would not be too deep.

After placing the plants I added a couple of more concrete blocks to create a base for the decorative rocks and waterfall.  I put the pump behind the rocks to hide the cord and minimize turbulence.  The pump hose was was positioned on top of the waterfall rock and additional stones were used to press the hose in place.

Now with everything in place I filled the tub with water until the leaves of the waterlily were floating loosely on the surface.  The water was hazy for a couple of hours, but by the next day it was clear as seen above.  

Most water lilies like full sun, some like 'Helvola' tolerate part sun.  In its present location this container gets about 4 hours of direct sunlight.  Since the flowers open in response to sun (and close up in the evening) a sunnier site will keep the flowers open longer.

Sunday, May 28, 2017

Learning My Sedges

Identifying grasses is tough.  While each species is different in some way, these differences are often subtle and often evident only when the grass is in bloom or when the seeds are ripe.  Looking out on a meadow or fallow field we often see 'grass', but in North America there are about 5000 species of plants that look like grass.  Most of these can be lumped into 2 groups.  The largest is the grass family (Poacea), with over 3000 taxa in North America followed by the sedge family (Cyperaceae) with about 1400 North American taxa.  Common characteristics of grasses are that they have round hollow stems and there are joints, or a thickening, at the leaf nodes.  Most sedges have triangular stems that you can often feel when you roll the stem between your fingers.  When viewed from above the leaves are 120 deg. apart, corresponding to the triangular stem.  Unlike grasses these stems do not have joints.

On our property in rural Maryland we are blessed with a number of different sedges.  Most of these have eluded identification because I have been looking at them in mid-summer when the foliage was big and strong but there were no flowers or seeds in sight.  Last fall when I renovated a garden bed I transplanted in several of these 'mystery' sedges.  Now, closer to the house I could keep an eye on them and catch them in bloom.

The bloom time for the sedges varies by species and growing conditions.  This year they started in early spring and some are still going strong in late May.  Some species that bloom early in the season are Pennsylvania sedge (Carex pensylvanica), Appalachian sedge (C. appalachica), and white-tinged sedge (C. albicans).  Among the sedges that bloom in mid-spring are rosy sedge (C. rosea) and broad loose-flower sedge (C. laxiflora).  Sallow sedge (C. lurida) is one that blooms in early summer.

In the past I have used a book by Lauren Brown, Grasses, an Identification Guide, to try to figure out what I had.  This book is nice in that you can get close to an identification without dissecting the plant.  However, it is limited in the number of species it covers.  This year I used the on-line key at GoBotany developed by the New England Wildflower Society.  I was pretty useful but it requires that you have detailed information about the flowers or seeds to make much progress through the key.  It also provides links to botanical terms and has good photos of each species when you get to the end.  It's limitation is that it only covers species native to the New England states, but that is still an awful lot of plants.

Here are some of the species that I am pretty sure I've identified or confirmed this year:

Rosy sedge is a reliable shade tolerant sedge.  Here its growing in a
woodland bed with strawberry bush (Euonymus americanus)
and American alumroot (Heuchera americana).

Rosy Sedge (C. rosea) is one I have been pretty sure about, but I just wanted to confirm.  It grows really well in moist shady areas and its mounds of fine textured foliage create a peaceful mood.  It's growing along a path that is used by both humans and deer. It can handle a little foot traffic and somewhat compacted soils.

Broad looseflower sedge name becomes clear
when it is allowed to go into flower.  Its leaves
get wider and the flowing culm flops over as it grows.
Broad loose-flower sedge (C. laxiflora) is very common here.  It is essentially evergreen and seems to survive out in the lawn even with weekly mowings.  This year I finally caught it in bloom and was able to run it through the identification key.  What stands out to me is that the leaf blade is folded along 3 veins giving it 'W' shape in cross-section.  In the past I may have ID'd this one as spreading sedge (C. laxiculmis).

Here, some smooth sheathed sedge is in flower in open shade.
The other grass at ground level is nimblewill (Muhlenbergia schreberi)
and a mayapple (Podophyllum peltatum) that was added in, is behind.
Smooth sheathed sedge (C. laevivaginata) is unassuming when not in bloom.  Its foliage resembles that of loose-flowered sedge in that it has a 'W' fold. In bloom it has a tall stalk topped with several tightly packed florets.

This group of weak stellate sedge is growing in an upland meadow/woodland edge
partly shaded by a mulberry tree and many taller perennials.
Weak stellate sedge (C. seorsa) looks like a much larger version of rosy sedge early in flower development (early May).  As the seeds develop they get much larger.  My sample looked similar to photos on the internet, but there some minor differences, such as lacking a bract (narrow leaf) just below the lowest floret.  I am 80% sure of this assignment.

Growing next to the stellate sedge is what appears to be pale sedge (C. pallescens).   This one stood out from other nearby sedges because the spikelets are on short stems rather being held tightly to the main stem.  This is a more northern species, not too common in Maryland.  For that reason I am a little skeptical about this assignment.

An important feature to note when using this identification key is where do the male flowers appear.  They can be on a separate spike at the top of the stem, they could be mixed in a spikelet with the female flowers, either above or below, or they could be on separate plants.  Another important feature to note is whether the pericarp (where the seed is formed) is divided into sections of two or three.

I often get too wrapped up with trying to name a plant.  Sometimes I just need to chill out and enjoy the plants for how they look and how they work in the garden.