Groundcovers, do they need to be green all the time?

As I think about the landscapes that I have idealized from an early age, they are green and full of life all year long.  But I grew up in an area that did not have four seasons and at a time when droughts and water management were not something that we worried about.  So the expectation of having some sort of green ground cover 365 days a year was not difficult to achieve.  Now after living in the Northern half of the US for 40 some years I have come to realize that having four seasons means that there is a good chunk of time when the plants in the landscape take a break and rest. 

Vinca minor is a widely used and invasive groundcover, originally from
central and southern Europe, that is often used where an evergreen carpet is desired.   

English ivy forms a dense evergreen cover that spreads by both
 runners and seeds.  It is particularly damaging when it is allowed to climb trees.

This brings up a question, does all the ground need to be covered all the time?  Yes, for protection from erosion, extreme temperature fluctuations and evaporation coverage is beneficial.  Groundcovers, both living and dead, also provide wildlife habitat.  There has been increasing awareness of the importance of  providing habitat for overwintering insects as they are critical sources of food for birds and other predators.

Alleghany spurge, Pachysandra procumbens, native to the mountains
of the Southeast, acts as a more naturalistic groundcover.

Does it need to be green all the time? No, not really.  But there is a desire among many for a lush green ground covering year around.  This desire is' might I say, for primarily aesthetic reasons.  To get this year-round green in temperate climates many folks are drawn to non-native species like Japanese pachysandra, English ivy, Vinca minor , yellow archangel (Lamiastrum galeobdolon), wintercreeper euonymus, mondo grass and lilyturf.  Most of these species are invasive in many parts of North America.

Here's my listing of the importance of having a ground cover, roughly in order of importance:

Minimize Erosion by holding soil against the forces of rain and wind;
Water management, by improving water infiltration and reducing evaporation;
Soil Health, by avoiding compaction, maintaining good aeration, moderation temperature and moisture extremes.  All these help maintain a healthy soil microbiota;
Maintain ecology by providing places for native insects to overwinter, less disturbance provides better survival rates for overwintering insects and nesting sites;
Weed management, its harder for seeds to geminate on shaded soil, in competition with established plants or where roots cannot take hold; and,
Aesthetics, create a visually pleasing composition.

As I alluded to above, the ground cover does not need to be green and growing year round.  In fact, depending on the climate and the environment the most appropriate ground cover may not be green at all.

In the majority of cases the material covering the ground will be some sort of plant material.  Having a actively growing root network under the soil to stabilize it and keep it biologically active is the ultimate goal. Where climate and conditions allow having a living mulch is an ideal solution for protecting the ground. The plants making up this living mulch need not be green though all four seasons.  They just need to continue to to hold the soil in place.  Green and actively growing on top is nice but not a year-round necessity.

The following are descriptions of how natural groundcovers function in three habitats that are similar to what you might encounter in a residential setting: Woodlands, Grasslands, and Deserts.

Mayapples, Podophyllum peltatum, provide a dense cover throughout
the spring as the forest canopy leafs out.  They hold the soil
with a wide spreading network of rhizomes.

Spring beauties are another spring ephemeral that are found on forest edges.

Woodlands: In Eastern deciduous forests the ground is covered year around by a layer of decomposing fallen leaves, natural compost.  Similarly, in coniferous forest there is a slowly decomposing layer of fallen needles.   Depending on the amount of light there is an understory of perennials and shrubs adapted to those conditions.  Where there are gaps in the canopy and accessible soil, new plants can get a start.  Depending on the composition of the seed bank these may be native or non-native species.  In a well balanced system the amount of undergrowth will be determined by the available resources.  Because of the way the available light changes through the year the nature of the ground cover plants also changes through the seasons.  In springtime the ground may be covered with ephemeral species like mayapples and Dutchman's breeches.  By summer these disappear and the ground plane is less densely covered with shade tolerant species like ferns and sedges and understory trees and shrubs.  Fall and winter feature the return of fall leaves which slowly decompose to replenish the soil with nutrients as well as serve as habitat for overwintering creatures.

Grasslands: In grasslands the winter ground cover consists of dead leaves and stalks from the past growing season and a network of crowns of the overwintering plants.  A healthy layer of this plant debris serves to protect the soil and fill the necessary roles of a ground cover.  The root networks of perennial grasses and forbs help to hold the soil.  Standing stalks of tall grasses and perennials form important habitat for some overwintering birds and insects.  Where the ground has been cleared by natural (fire) or unnatural (cutting and raking) processes, space is opened up for new plants to grow, both desirable and unwanted, depending on the seeds that are present.

Little bluestem, Schizachyrium scoparium, is a common
component of many eastern grasslands and dry meadows. 
Even after it dies back in winter it maintains its visual appeal.

Arid lands: In desert environments growth is limited by the availability of resources, particularly water.  Here you typically see plants growing much further apart because they are limited by the amount of available moisture. Root systems of perennial species tend to be much larger in order to access sufficient moisture for growth and survival.  Particularly in hot deserts most of the organic material that falls to the ground gets burned up and does not contribute to build organic material in the soil for the long term.  In these environments a natural ground cover would be inorganic in nature, rocks, stone and sand. While plants may not stabilize the soil on the surface, many have very wide spreading shallow roots systems adapted to harvest rainfall before it evaporates.   These wide systems can help to stabilize the soil, leading to less erosion.  Trying to maintain a green ground cover in a desert environment can be very resource demanding and not at all sustainable.

The ocotillo and purple-tinged prickly pear cactus each have shallow
wide-spreading roots to scavenge water thus limiting what else can grow nearby.

If green in winter is really what you need there are several native species here in the Mid-Atlantic that fit the bill.  Native (near)evergreens include, wintergreen (Gaultheria procumbens), green and gold (Chrysogonum virginianum), heuchera, tiarella, Alleghany spurge (Pachysandra procumbens), golden groundsel (Packera aurea), evergreen ferns (Christmas and intermediate wood ferns) and some sedges, like creeping sedge (Carex laxiculmis) are good for partly shaded locations.  For sunnier sites moss phlox (Phlox subulata), wild strawberry (Fragaria virginiana), common and creeping junipers, barren strawberry (Geum ternatum), as well as some grass-like plants like prickly bog sedge (Carex howei).  On most sites these plants will still be green through most of the winter, but they generally will not be lush with fresh foliage

Golden groundsel in winter.  The interconnected leaf rosettes
are held close to the soil.

In spring golden groundsel puts on fresh growth and sends up flowers.  

Pull! Pull! Pull!

 Yes Pull!  Now is the time to pull out Japanese stiltgrass, Microstegium vimineum.  This invasive species is rampant in the eastern U.S. from Georgia to Massachusetts and west to the Mississippi River.  It affects home landscapes and natural area alike.  Here in the Mid-Atlantic region the grass is putting on a growth spurt prior to going into bloom.  So the plant is expending a lot energy now to grow taller and produce flowers.  It also means that it is a lot easier to pull out without getting on you knees.  Since this grass in an annual, keeping it from going to seed can go along way to controlling its spread and reducing its numbers.  

Early in the growing season Japanese stiltgrass stays relatively low, rooting at several nodes along the stem.  In late July it starts growing upward to gets its flowers higher off the ground.  If it were only that simple.  Stiltgrass not only produces flowers at the top of the stem it also has flowers at most of the vertical leaf nodes buried within the stems.  These are referred to as cleistogamous flowers.  

  This image shows flowers at the top and at the
lowest nodes. Cleistogamous flowers can occur all
along the stem as well.  Roots can also form roots at each
node where they contact the ground. If the grass is not
cut early in the season most of the flowers are
concentrated toward the top of the stem.

These cleistogamous flowers are one of the reasons stiltgrass is so hard to eliminate.  If you cut or mow stiltgrass early in the season without removing it completely, these stem flowers will form even lower on the plant requiring even more careful pulling later on.  I've seen a recommendation to leave the stiltgrass grow until late summer so that most of the flowers are higher in the plant.  Then when you pull you are able to get most all of the flowers with the least effort.  (Sounds good to me.)

Here are some highlights of my nearly 10-year battle with stiltgrass here in Maryland:

Pre-emergent herbicides are very effective in existing lawns and smooth surfaces.  These chemicals interfere with the development of germinating seeds but do not have a strong effect on established plants.  These must be applied in early spring prior to the germination of the stiltgrass seeds.   I have been using a preemergent containing Dimension (dithiopyr) for several years.  I took two years of successive treatments to get nearly complete removal of stiltgrass from the lawn in treated areas.  Moss has not been effected. 

Late summer pulling of previously uncut stiltgrass, especially in shady areas, has reduced the amount of stiltgrass in subsequent years.  This does require a multiyear effort.  Since nasty things like poison ivy, multiflora rose and wineberry can hide in the tall stiltgrass, it is important to wear gloves and arm protection when pulling.

Here's the before photo.  I wonder why there is so much
stiltgrass just in this area, and why so close to the path. 
It could be from the lawn mower blowing seed from
 the other side of the path where there is a lot more stiltgrass

After about 30 minutes of labor you can see the
existing plants reappear. (Some of the freshly
pulled stiltgrass is piled in the foreground-left.)

Weed-whacking and raking of the cut grass before it begins to bloom is very effective, BUT you need to get really close to the ground to remove all the stiltgrass. Raking up the cut grass helps existing plants bounce back. 

Identify and plant native species that can compete with stiltgrass. Two exceptional plants that seem to outcompete stiltgrass are golden ragwort (Packera aurea), and mayapple (Podophyllum peltatum).  Other plants that are strong competitors include clearweed ( Pilea pumila) and grasses that grow well in shade: river oats (Chasmantheum latifolium), mannagrass (Glycera sp.), Virginia wildrye (Elymus virginicus), and  nimblewill (Muhlenbergia schreberi).  Also there are a number of sedges that will persist under cover of stiltgrass and can form a dense cover if given the chance.  Rosy sedge (Carex rosea) is one example that does quite well on my property.  I recently noticed that there was much less stiltgrass growing in an area where celandine poppy (Stylophorum diphyllum) and mannagrass have been spreading.  The exclusion of stiltgrass is not as great as with Packera, but it is noticeable.

This opening under the trees is free of both garlic mustard and stiltgrass now. 
In early spring it is fully covered with mayapples and a few woodland phlox.

The area just beyond the bench has benefited from annual late
summer pulling and by a dense crop of mannagrass that totally
shaded the area from late April to early June.  The stiltgrass that is
growing there now is only a few inches tall.  Compare that
to the 2 foot tall stiltgrass in the foreground-left.

It's not just pulling in late summer and fall.  There are things you can do earlier in the year to control stiltgrass.  Here is a table summarizing some removal strategies:

Japanese Stiltgrass Control

Season	Actions	Pros	Cons	Comments
Late Winter Early Spring	Pre-emergent treatment	Effective in lawns and smoother (even) surfaces with access to soil surface.  Allows lawns and perennials to get a head start.	Will affect all germinating seeds for several months.  Uneven coverage on rough surfaces.  Application needs to be at the right time (same time as for crabgrass).	Takes at least 2 years to knock down seed bank to see significant progress.  More time to complete elimination, if ever. Many pre-emergents for crabgrass control are also approved for Japanese stiltgrass (aka Mary's grass, on the label)
Late spring-Summer	Herbicide	Grass selective herbicide leaves broad leaf plants and some sedges intact. Try products containing Fluazifop-p-butyl	Difficult to control collateral damage, especially with non-selective herbicides	Targeted application and use of selective materials may limit side effects.
Late spring-Summer	Pulling	Non-toxic and selective.  Opens space for other species.	Labor intensive; left over stilt grass will expand to fill gaps.	If removal is not complete this will need to be repeated at the end of summer
Late summer/Early fall	Cutting/ pulling/ burning	All methods to reduce the amount of seed	Need to complete actions before seed begins to ripen.	Copious amounts of seed being produced, need to be thorough and avoid spreading any ripened seed.

You can read more information about my on-going battle with Japanese stiltgrass in previous blog-posts by entering 'Microstegium' in the 'Search this Blog' box at the top of this page.

Good luck and I would like to hear about your experiences battling this invasive species.

2020 Stiltgrass Wrapup

As we are coming to the end of stiltgrass season for 2020 I wanted to review what I’ve learned about controlling this invasive species on my Mid-Atlantic property over this year. 

Pulling 
Pulling Japanese stiltgrass, Microstegium vimineum, is an effective means for controlling this annual grass, but it is extremely labor intensive.  While its primary germination period is mid-spring it does continue to germinate into summer, particularly if more openings appear in a previously shaded area.  So you may find that you need to redo areas in late summer that you thought had been taken care of earlier.  This was the case in a shaded woodland where I thought I did a pretty good job clearing the stiltgrass at the end of July.  When I returned to that place in mid-September it was in need of more pulling.  Apparently I left enough scraps around that they were able to regrow.  So if you only want to pull stiltgrass once in a season get every bit out the first time, or wait until just before it goes to seed, maybe early September (depending on local conditions) and then pull out all that you can. 

This was the initial condition, before any clearing in 2020.

This was after clearing in late July, by September this area was
overgrown again with stiltgrass.  This time it only took about 10 minutes
to clear the area.  The underlying Rosey sedge, Carex rosea, still looked good.

While searching for more information about the cleistogamous seeds in stiltgrass (those seeds hidden in the stem), I found a Master’s thesis by Samantha Nestory of the University of Delaware.  There it was noted that Japanese stiltgrass grown in sunnier locations had more cleistogamous seed than in shade, 47% vs 28%.  It also pointed out that, at maturity, there is a cleistogamous flower stalk at nearly every joint along the stem. After reading this I checked out some of the stiltgrass that was ripening.  Sure enough, nearly every joint had a flower stalk hidden or nearly hidden within.  In the woodlands I did not find as many of these hidden flower stalks.  Another observation about JSG is that it is able to put out roots wherever a leaf node, or joint, touches the ground.  By this means a single stiltgrass seedling can cover a large area.  Also residual fragments can quickly reestablish.  I’m not sure what this means for stiltgrass that is pulled then dropped back on the ground.  Will it reroot? 

Next to my finger you can see the flower stalk that was hidden under the leaf sheath. 
In sunny locations by early fall there can be one of these at each joint.

This brings up the topic of how to allocate our most precious resource, time.  While I often dive into some of the most thickly infested areas and rip out the biggest plants, it is actually more effective to begin in less densely infested areas and clear them completely.  After those areas are clear, move on to thicker areas.  The idea is that if an area is totally clear you won’t need to come back to redo it as much.  Whereas while you are battling a thick infestation, the lightly infested area is getting worse and then you end up with twice as much heavily infested space. 

Here's a small scale example of complete removal of Japanese stiltgrass. 
Ideally, I won't have to come back again this year and can spend my time elsewhere. 

Lawn 
This year I was late on reseeding the lawn.  I didn't get out there until early October.  I typically use a bow rake to tear our residual stiltgrass, then overseed with an appropriate cool season turf grass in mid-September.  (We are near the southern limits of where cool season grasses are preferred.)  Overseeding helps to fill in the gaps in the lawn that would otherwise be filled by more stiltgrass.  By seeding in fall these cool season grasses can get established and not be affected when I apply a pre-emergent herbicide in the spring to kill the stiltgrass.  I should have raked out the stiltgrass much earlier, before the seed was ripening.

Herbicides
I’ve had great success controlling stiltgrass in the lawn using pre-emergent herbicides in early spring.  Most products labelled for pre-emergent use to control crabgrass are effective.  I have noticed that the amount of hairy cress, Cardamine hirsuta, has also been reduced (this is due in part to mowing at least once in mid-spring to cut off the flowers before they can set seed.) While the pre-emergent works very well in the lawn, it is not as effective in the rougher meadow areas.  

In this mini-meadow I have started to use the pre-emergent herbicide Dimension™
to augment pulling of Japanese stiltgrass.  Naturally occurring species that are flourishing
here include deer tongue and purpletop grasses, wingstem (Verbesina alternafolia)
and wild blackberry.  I have also planted in some panic grass, wild bergamot and brown-eyed Susan.

After two years of treatment in small meadow I have opened up enough space to get some more desirable plants established like wild beebalm, Monarda fistulosa, black-eyed and brown-eyed Susans, Rudbeckia sp.,and grasses like Virginia wild rye, Elymus virginicus, and panic grass, Panicum virgatum.  I noted this year that, in addition to a decrease in stiltgrass, the nonnative invasive bull thistle, Cirsium vulgare, was largely absent this year.  This thistle is a short lived annual or biennial species so is susceptible to control by pre-emergent herbicides.  I have been watching for other changes in the species mix because of the pre-emergent treatments.  Since I have put in some black-eyed Susans, which depend on reseeding to survive, I will not use pre-emergent in that area next spring to see if I can get them to come back on their own.  Ideally I would like to build up a strong network of native species that can exclude the stiltgrass on their own. 

I have not been using post-emergent herbicides on Japanese stiltgrass, but they do have their place in the arsenal. I found research that indicated that the use of grass selective herbicide can be effective, without causing damage to non-grass species.  Fluazifop-p-butyl is a selective post-emergent herbicide that can adequately control M. vimineum with minimal effect on the non-graminoid native plant community (Judge et al. 2005b). Fenoxaprop-p-ethyl, is a selective post-emergent herbicide that provides excellent control of M. vimineum and can maintain or even increase cover and richness of native species post-treatment (Judge et al. 2005a, b, Judge et al. 2008, Pomp et al. 2010, Ward and Mervosh 2012).  Fenoxaprop is not effective on sedges or cool season perennial grasses, like red fescue, so that would be a good thing, since there are many sedge species occupying my woods.  However there are also many shade tolerant grasses like bottlebrush grass, deer tongue grass and mannagrasses that could be affected.  So I would be hesitant to use these useless it was in a very targeted fashion.

 Fire
These past few years I’ve been using fire, primarily from a garden torch, to control Japanese stiltgrass.  I’ve found that fire is good for clearing a space prior to planting, but not for clearing without a plan for back fill with desirable species.  In some areas I’ve burned the stiltgrass seedlings in early summer only to have the area recovered with more stiltgrass; mostly from rooted stems coming in from nearby plants. Fire alone is more effective in late in season (August) when there is not enough time for new JSG to germinate and reach maturity.  It can work particularly well if there are well rooted perennials in the area.  These perennials are able to resprout after their tops have been singed off.  Cool season perennial grasses are a good example of these.

Here I used my garden torch to burn away the stiltgrass. 
Then I planted some plugs of switch grass, Panicum virgatum.

This year I also used fire to dispose of late season stiltgrass that was full of seed.  After realizing just how much seed is contained in a stiltgrass stem, I decided that rather than moving piles of stiltgrass around I would burn what I had in a central location.  Fortunately, I live in an area with plenty of space and that allows burning.  The key to getting stiltgrass to burn well is to allow it to dry out.  I allowed my big piles [photo] of stiltgrass to dry about 2 weeks to get it dry enough to burn rapidly,  In all I estimate I had nearly 2 cubic yards of stiltgrass stems plus thatch from where I reseeded.  This was reduced to less than 2 cubic feet of smoldering ash. [photo].  When burning remember to follow all local regulations.  Don’t burn on windy days, keep the flames under control, and have water on hand to put out any unintended fires and dowse the ashes when done.

These piles of ripe stiltgrass, plus some additional thatch raked out of the lawn,
were reduced to a couple of cubic feet of ash.

Native Competitors
A more exciting aspect of stiltgrass control is finding native plants to fill in or even resist Japanese switchgrass.  Many people, myself included, have noted that golden ragwort, Packera aurea, is very effective at excluding JSG.  

In the woods nearby is a large dense patch of mayapples, Podophylum peltatum, a spring ephemeral.  I have noticed that during garlic mustard season (April to June) there is no garlic mustard growing there.  This year I also realized that there was not any stiltgrass there either, even though the ground is essentially bare save a few sedges and Virginia creeper, once the mayapple has retired for the summer.  I recently saw a post on Facebook where there was a patch of wild ginger, Asarum canadense, that was relatively free of JSG.  These two species spread extensively by rhizomes.  May there’s something to that?  

In early through spring the area circled is covered with mayapples. 
This dense cover seems to have excluded both garlic mustard and Japanese stiltgrass.

There are also grasses that maybe useful.  River oats, Chasmantheum latifolium, grows in dense stands and I have found stiltgrass only on the outer edges.  In the woods the rosy sedge, Carex rosea, has done very well with just a little help from me. In a moist wooded area I noticed that I had an early season grass that excluded the stiltgrass until it went to seed in June.  I’m pretty sure it was a species of mannagrass, Glyceria sp.  (I keyed it out as American mannagrass, G. grandis, but that is a rare species in Maryland, so I will double check when it blooms again next spring.)  In late summer while pulling stiltgrass I came across another patch of grass that had just a very few stiltgrass stems.  Currently unidentified, it seems to block the stiltgrass with a dense layer of thatch from a previous season’s growth.  This is another one to try to identify come spring.

This small, yet unidentified grass seems to have repelled an invasion of stiltgrass.

Next Year:

• Continue with the pre-emergent treatments on the lawn and in limited areas in the meadows.
• Focus my efforts in areas to achieve 'complete' removal before moving on to new areas.
• When burning to clear an area have something ready to fill in.
• Identify those grasses and see what else is holding its ground.

If you have any additional ideas or know of other competitive native species I'd love it if you could share that here!

 

New Seedlings and Sprouts

While a few established plants did not make it through this past winter most did and are performing quite well now.   A number of plants that I put in last fall which I had written off as lost 'suddenly' reappeared in the middle of May.  These include a Passion Vine,  some New York fern and False Goatsbeard (Astilbe biternata).  It was very fortunate that I left the plant tags in the ground otherwise I may have totally missed these late arrivals and possibly removed them as weeds or planted something else on top of them.   The False Goatsbeard is an excellent example.  This was a new plant for me so I did not know when it would resprout or what it would look like.  As the photo shows the new shoot could easily be mistaken for a dead twig.  Now that it has leafed out it looks like what I would expect for and Astilbe.

The new shoot comes up reddish-brown with tightly curled leaves.

Astilbe biternata is the only North American species of Astilbe.  It grows to over 3' tall.

The intensity of the red markings on the leaves is variable in the wild type plants

I have mentioned many times before that we are on a mission to remove the Garlic Mustard from our property.  In addition to improving the biodiversity it is giving us the opportunity to closely observe the other plants that were growing under the mustard canopy.  The other day after pulling some garlic mustard I found a patch of Jumpseed, Persicaria virginiana, (formerly Polygonum virginiana) that was growing in an unmanaged area.  I wanted to compare this to some red-flowered Jumpseed that I got from a nearby nursery.  

These Jumpseed from a nursery have a similar number of leaf veins,
but the shapes of its leaves is variable.

 Because most Jumpseed blooms with whitish flowers I was uncertain whether the red flowered plants were North American (var. virginiana f. rubra) or from an Asian species (var. filiformis) which normally has red flowers.  These varieties have different leaf shapes and number of veins on the leaf.  See this link for the original publication.  The characteristic leaf shape for the Asian species is obovate with an attenuate or cunnate base.  The nursery-grown plants have similar number of veins as the wild type (5-9 pairs), but the leaf shape is variable with a single plant having leaf shapes that match either species description.  Bottom line... I'm just not sure.

No garlic mustard in these Mayapples, but there
was woodland phlox and some galium species mixed in.

Another thing we noticed was that there was a large patch of Mayapples (Podophyllum peltatum) that was nearly devoid of garlic mustard.  I don't know if the Mayapples are actively defending against garlic mustard invasion or if this area has just not been invaded yet.  It does support the practice of having a good dense ground cover to shade out/exclude invasive species.  

Seedlings

I am seeing seedlings returning from 2 native annuals that I set out last year.  I am finding large masses of American Pennyroyal, Hedoma pulegioides,  near where I had planted them last year.  The seed that I sowed last spring did not germinate well last year (only 1 or 2  plants).  But seeds that had over-wintered are germinating like gang busters.  So despite what the seed packet says, some cold, moist stratification or fall planting of this species gives much better results.  I am encouraging these in my vegetable garden because they are reported to repel crawling insects due to the strong aromatic scent.  I am hope that it will have a similar effect on mammals as well.

 

These seedlings look similar to those of some Salvia species;
however, they can be distinguished by their strong aromatic scent even at this age.

The other annual that is coming back is Partridge Pea, Chamaecrista fasciculata.  Last year I started most of these indoors after  2 weeks cold, moist stratification and pretreatment with an rhizobactrium innoculant.   These germinated quite well both indoors and out.  This spring I am seeing many new seedlings near to their parent plants. 

The leaflets of Partridge Pea will fold up at night and when briskly jostled.

These blooms have just opened, the white petals
doubled in length a couple of days later.

As I was coming back from pulling more garlic mustard I stumbled upon another plant that I did not see last year.  I believed that it was Robin's Plantain, Erigeron pulchellus, because of the larger flowers and the spatulate basal leaves.  On digging a little deeper I realized that this was Common Fleabane, E. philadelphicus.  This species is indicated by the clasping leaves on the flower stalk. While not a beautiful garden plant is a pleasant surprise in the woods.  Most of my plants are actually growing on the path on the more compacted soil.  Perhaps I didn't see them last year because they had gotten trampled before they could bloom.

Just a note on the invasives front:  The garlic mustard is starting to go to seed now (late May), so we are trying to bag it up right away; also Mile-a-minute vine is starting to grow and the stilt grass is about an inch tall now.  It is really best to pull the mile-a-minute now before the thorns develop later in the season.

Getting into Spring: Wildflowers and managing Ticks

I have been fortunate not to have been bitten by any deer ticks so far.  One of the actions I am doing to keep that streak going is to put out homemade tick tubes twice a year.  These are paper tubes with several (5-8) cotton balls heavily treated with permethrin.  The idea is that mice will collect the cotton and use it in their nests.  There the permethrin will kill the ticks on the mice and break the deer tick life cycle early on.  Check out this link for more information.  We also spray our work clothes with a dilute solution of permethrin to deter ticks and especially chiggers.

I usually put out one batch of tubes in Mid-March, targeting a time when mice begin building nests.  I put them near brush piles and other places where mice might nest.  I use an orange flag to hold them in place and mark the location.  If there are still cotton balls left over I look for a different location to put the tube.  I also put out another set in the fall with the idea that mice will use them for their winter habitats.   

This springtime tube distribution also gets me out in the woods when the spring wildflowers are going to town.  This year has been more exciting than last.  It may have been the cold winter, or that my wife and I have been removing large quantities of garlic mustard, but the quantity of native wild flowers appears to be up. 

The flowers of Bloodroot only last a couple of days.

One plant that I missed entirely last year was Blootroot, Sanginaria canadensis.  In fact, I ordered a few of them to put into the garden, thinking I had none.  But an early March walk in the woods revealed that we have many of these plants.  One possible reason I missed seeing them before is that each plant has a very short blooming period, maybe 3-4 days, and I just wasn't in the right place at the right time.  

The three stem leaves on this Cutleaf Toothwort
are easy to see here.

Another early bloomer is the Cutleaf Toothwort, Dentaria laciniata.  The highly dissected leaves are a helpful clue to identifying this plant.  Also this Toothwort has three leaves on its flowering stalk, unlike its close relative D. diphylla, which has only two. These species have been moved over to the genus Cardamine and now it appears that the currently accepted name for the Cutleaf Toothwort is Cardamine concatenata.  

This was the only pink-tinged Dutchman's Breeches that I found.

One of the most common spring wildflowers in our woods is Dutchman's Breeches, Dicentra cucullaria.  Its flowers last longer than those of bloodroot.  Most of them are bright white.  However, a few plants have flowers that are pinkish.  Of the hundreds of plants in our woods I only found one with a pink coloration.  

Mayapples open like little umbrellas on the woodland floor.
These leaves will expand to 8 inches or more.

While they will not be blooming for a month or so, the leaves of Mayapple, Podophyllum peltatum, are appearing throughout the woodland areas.  Having a healthy layer of native ground covers like these should help in our battle against invasive species like garlic mustard and stiltgrass. 

I am trying a number of native ground covers like these under some pine trees
to replace the Vinca minor.

The Labrador Violet that I planted last season needed to be uncovered from a heavy layer of pine needles.  After a couple of days of exposure the leaves expanded and the first blooms opened up. 

I noticed that these blooms open the widest when the sun is at full strength.

In my last post I noted that there were many Spring Beauties and Spicebush beginning to bloom in the woodland areas.  I was asked whether these species would do well in full sun.  I do know of one or two Spicebushes that are growing in full sun in rather damp soil.  Then just the other day I noticed some Spring Beauties growing in the middle of the lawn in full sun.  So I guess the answer is yes; however, full sun is not their preferred habitat.

Needed to use my hat to get the flowers to be visible.

Last fall I planted several small Yellowroots, Xanthorhiza simplissima.  These plants flower just before the leaves open up.  It is very easy to miss these small maroon colored flowers.  The primary landscape use of Yellowroot is as a medium tall, fine textured ground cover.  

The pubescent flower stem is an identifying feature
of this species of Saxifage

My newest find while distributing the tick tubes was  Early Saxifrage, Micranthes virginensis.  These were growing at the base of a Beech tree mixed in with some white Spring Beauties.  The unique flower growing out of a basal rosette of bluntly lobed leaves stood out as something different from the other flowers in the area. 

The last wildflower that I spotted last week was a Dogtooth Violet, Erythronium americanum, growing near our house.  I had seen some growing near a stream but I was surprised to find this in an upland area.  It may have been planted there by the previous owner.  My wife spotted this as she was pulling out Garlic Mustard.  It is most easily recognized by the mottled foliage.  The flower is only present for a relatively short amount of time.

This Trout Lily started blooming about 2 weeks after the Bloodroot.  
This flower is on the pale side for E. americanum, it could be different species or a variation. (On looking more carefully, this is E. albidium, based on the spreading tip of the style; it's united in E. americanum.)

More Maryland Wildflowers - 2nd Week of April

Deciding which native plant to use in a developed suburban landscape was fairly straightforward for me.  I could choose the plants I wanted without regard for to how it would impact the surrounding plant communities.  [Re]-introduction of nearly any native species into a sea of Euonymus and Barberries and the like would be a step in the right direction.

Now that I am working in a rural landscape I am becoming more sensitive to how my new plantings will affect the existing plant and animal communities.  I am cautious about introducing species that don't belong, native or not.  One very helpful resource for me is Native Plants for Wildlife Habitat and Conservation Landscaping Chesapeake Bay Watershed from the US Fish and Wildlife Service.  This publication lists many native species found in the Chesapeake watershed including their native ecoregion (Mountain, Piedmont or Coastal) and state where each is found.  

As a designer I also want to insert some visual effects with form and color.  This may require broadening the plant palette, drawing in materials from other areas and even a few well behaved non-native plants to achieve a particular aesthetic effect.  In general I will utilize a wider variety of plants in the immediate vicinity of a house or other man-made feature.  As I move out to the edges of a property I narrow the plant selection to the regionally native species.  I try to avoid introducing any species that don't naturally belong there.  

So before I get too far in planning and planting new native gardens I need to do some surveys of what is already present.  This (finally) brings me to the topic of what I found growing during the second week of April.  The tree canopy was still pretty open and the woodland floor was really greening up.




The first thing that really hit me was the masses of Virginia Bluebells that were coming into bloom.  These started coming up about a month ago.  Some had purple tinged foliage that has since turned green.



I was very pleased to see large masses of Mayapples coming up, especially I had just bought a half dozen to plant along the driveway.  These look somewhat alien when they first break ground.  They have a large white flower that stays just under the leaf.  

Mayapple leaves open up like umbrellas, 6-8 inches across.  

Once leafed out Spicebush can still be identified by the spicy scent of its bark.

The number of Spring Beauties has finally peaked,
now the blooms remain only in the shadier spots.
Note the garlic mustard off to the right.

Spicebush was another plant that I had just purchased to add to driveway area.  I was very happy to see a large mass of these growing near the creek.  The little flower clusters add an ethereal yellow haze to the scene.  These are not as garish as the Forsythia that are also in full bloom at this time.  






The Spring Beauties, Claytonia virginica, are continuing to come out - now the ground is sprinkled with the pale pink blooms.  The Dutchman's Breeches, Dicentra cucullaria, have also come into fuller bloom.  Some are white and others have a yellowish cast.  

Flowers started out a pale green
before opening up and turning white.

In with the Dutchman's Breeches is a plant with similar finely divided foliage, but this one had tubular yellow flowers.  It turns out that this is Yellow Fumewort, Corydalis flavula.  This native annual is 4-12 inches tall and has glaucous green foliage similar to other Corydalis.  I had never seen this before and was suspicious that it may some of the non-native Yellow Corydalis (C. lutea) that escaped from a garden.  The distinguishing feature from other yellow Corydalis (C. aurea and lutea) is that the upper lip of the flower is toothed.  This species is rare in New England, but not uncommon further south and west.

This winter annual was probably among the
early foliage seen back in January

The upper lip of the flower is toothed.  Also,
 seed pods are visible just below the flower on the left.

Should be getting some yellow flowers from these Trout Lilies in a couple of weeks.
If they are white, then these would be White Trout Lily, E. albidum.

Down in the leaf litter I noticed the spotted leaves of Trout Lily, Erythronium.  No blooms or buds were evident at this time, so I will need to get back down to these is a week or so to catch them in bloom.  As I was climbing back up away from the stream I noticed that the Toothwort were finally in bloom.  The dangling white flowers are not spectacular on their own, but they complement the other ephemerals. The Woodland Phlox, Phlox divaricata, are putting up flower buds, but I did not see any in bloom.  Back up on the lawn I am seeing Common Blue Violet, Viola papilionacea, complemented by the yellow flowers of Rough Cinquefoil, Potentilla norvegica.  Oops, these are actually the non-native Indian Strawberry, Duchesnea indica, see the comments below.

Each flower stalk of these toothworts has a pair
of deeply tri-lobed leaves, hence the epithet  'diphylla'.

Woodland Phlox has formed it flower buds.  Opps, this is actually Cardamine laciniata.

Common Blue Violet has hairless flower stalks,
otherwise this could be Woolly Blue Violet, V. sororia.

Unlike other weedy Cinquifoils, Rough Cinquifoil has
trilobed leaves and relatively large blunt-tipped flowers.  However, this is actually
Indian Strawberry, Duchesnea indica. with larger flowers than the Cinquifoil
and later a red berry.

Along with all of these natives there is a large population of garlic mustard that are beginning to bloom now.  Removing these will be a long and tedious process.  I have put a supply of black trash bags around the property to collect these.  In areas where the soil is moist it is possible to get most of the root out by gently pulling the plant by its crown.  Garlic mustard has a lot of stored energy in its root and may be able to set seed even though it has been pulled out of the ground.  A good practice is to bag them up and let them bake in the sun for a while before sending them to the landfill.  Garlic mustard should not be put into your compost. However, it is edible and you can make a decent pesto from it.