Wednesday, December 28, 2022

What to do with Wild Persimmons?

When we first moved to this relatively spacious property in Maryland just over 10 years ago I knew that I wanted to grow more native plants that could provide food, primarily for wildlife, but also food that I might enjoy.  One of those target species was wild or common persimmon, Diospyros virginiana.  I’ll admit that going into this I did not have any firsthand knowledge of how to grow persimmons or really just what they tested like.

An 10 year old persimmon tree, about 25' tall. 
It has a nice upright form angular branching. 
Fall color is yellow for my trees

A little internet research got me started.  I learned that wildlife really liked to eat persimmons, but not until they were ripe.  An unripe persimmon is loaded with tannic acid giving them an extremely astringent taste.  I've tried some partially ripe persimmons and it is  like having bitter sawdust in your mouth.  Also when growing persimmons for harvest you need to know that they are dioecious, that is there are distinct male and female plants. You need to have at least one of each sex to get fruit.  The native range for Diospyros virginiana is from New Jersey down to Florida and westward to East Texas and eastern Kansas.  So Maryland is well within it native range.  

Most female flowers are well spaced along the stem and are usually solitary. 
These have sterile anthers around the ovary so, superficially, 
male and female flowers look similar.

Male flowers are more tightly packed along the stems in clusters of
1-3 at a node. The number and distribution of flowers is
a good way to tell if you have a male or female tree.

Unripe fruits are dark green and can be difficult to locate.  
As they ripen they turn orangey-yellow.  A perfectly 
ripe fruit is mushy and somewhat wrinkly.

The fruits of common persimmon are 1-1.5” in diameter.  Initially green the fruits turn bright orange as they ripen.  A fully ripe persimmon is deep orange in color and somewhat to very mushy.   Around here I was picking ripe fruits from the end of September through October.  While visually unappealing it tastes great and is very sweet.  To me, it tastes like a mixture of very ripe apricot and banana.  Unfortunately this means that there is a very narrow window of opportunity for harvesting edible persimmons.  A ripe persimmon is too mushy to transport any distance in bulk.  Another less attractive feature is that they have several relatively large seeds that hold tightly to the tasty flesh.


The deeply furrowed bark on this mature tree is
a distinctive feature of persimmon trees

Ripe common persimmons.  Nice and mushy. The one in front is perfectly ripe.

In a grocery store, the persimmons you are likely to find are from an Asian species, Diospyros kaki.  The most common types are Fuyu and Hachiya.  The smaller Fuyu persimmon has seeds and is less astringent, while the larger Hachiya is seedless, but is more astringent until fully ripe (mushy).  I did a taste comparison among these two and my homegrown common persimmons.   The Fuyu had a milder taste and was palatable even when not fully ripe.  The seedless Hachiya needs to be completely ripe (mushy) before it can be fully enjoyed.    As it is seedless it has the additional advantage of having much more edible fruit than either the Fuyu or common persimmons.  Asian persimmons will ripen sitting on a counter top or, more quickly, in a bag with an apple or banana. 

Of the three I found the common persimmon to be the sweetest and most flavorful.  However, the flesh to seed ratio is very low and it, like the Hachiya, must be fully ripe to enjoy its full flavor.  Probably the biggest drawback of the common persimmon is that it is really not that common.  It is not commercially available and is at its best when used within a couple of day of picking. 

Store-bought Asian persimmons

Fuyu persimmon on left has a few seeds, the Hachiya (right) is seedless.

So if you really want firsthand experience with common persimmons you need to have access to a tree, a female one specifically.  Growing a persimmon tree is not too difficult.  The trick is to have both a male and female tree close enough together to allow for pollination.  Common persimmon trees are classified as small canopy trees, growing 50-75 feet in height and a spread of 35-50 feet.  It has an ovoid shape.  The foliage is medium textured with most leaves being 3-4” long.  The trees are tolerant of a range of soil conditions, but they need full sun.  They are winter hardy to zone 5a.

When purchasing a common persimmon tree from the nursery there is no indication whether it is a male or female plant.  There is, however, one cultivar referred to as a Meader Persimmon that is self-fertile and produces seedless fruits.  The best strategy is to get at least 5 trees and hope that you will have a mix of sexes.  For the trees that I planted it took about 5 years before they bore flowers so that I could tell which were male and which were female.  At 7 years in the ground I started getting fruits.  Of the 6 trees that I planted 9 years ago, 2 are male, two are female and two have yet to bear flowers.  (One of these is in a shady location and the other started as a 6” bare root plant.)  I took about 7 years before I began to get any fruits.  Now each year the yields have been increasing significantly.

What Now?

Now that I have invested 7 years in growing my persimmon trees I needed to figure out what to do with them.  Because of the short shelf life of wild persimmons the best way to enjoy them over time is to preserve them in some way.  The mushy flesh of ripe persimmons can be separated from the seeds using a food mill.  The resulting pulp can be frozen for later use or processed into jams or jellies.  There are a number of articles and videos on-line that demonstrate how to process wild persimmons.  Here’s a link to a video that I found useful.  And here’s an article from Indiana Public Media that describes an easy way to make persimmon jam.  This year I only had about a dozen ripe fruits at a time so I opted to make wild persimmon simple syrup that could be easily scaled to the amount of fruit I had.

The ingredients for a persimmon simple syrup that just highlights the flavor of the fruit are:

1 pound of persimmons
1 cup water
1 cup sugar
1 tsp lemon juice

Persimmons, seeds and all are simmered with sugar and water for about a half hour

The whole ripe (mushy) persimmons, water and sugar are combined in a small saucepan and simmered for a half hour.  I peeled the persimmons because it the pulp slipped out of the skins so easily. (This minimized the risk of having some astringency from the peels; however, when fully ripe the skin has no taste.)  Mash up the pulp in the hot liquid several times while simmering.  After about 20 minutes, add the lemon juice.  After 30 minutes of simmering allow the mixture to cool then put it into a cheesecloth and squeeze out the nearly clear liquid.  This recipe yields about a cup of simple syrup.  The remaining pulp had very little flavor left in it.  The syrup can be stored in the refrigerator for several weeks.

The syrup is separated from the pulp by squeezing it 
through a couple of layers of cheesecloth.  

I tried this simple syrup in several cocktails that call for simple syrup.  I found that it worked really well in a whiskey or rum sour.  I also tried it in a lemon drop recipe, but the flavors didn’t work well together, to my taste.

Next year, assuming I will get even more persimmons maybe I'll try making a persimmon pudding.

Wednesday, November 9, 2022

Why Lawn

Lawn maintenance consumes an incredible amount of time and money.  But what is the purpose of a lawn, and could those resources be put to better use?

Let’s first start with the question:  Why have a lawn?  There are some practical reasons.  Recreation - lawns are often used as open and safe places for children, and some adults, to play.  Protection - having open sightlines around your dwelling, with few hiding spaces can make one feel safer.   Buffer space - keeping nature at a ‘safe’ distance.  This could be to control insects or wildlife, or, in fire prone areas, an open, healthy, lawn can protect a dwelling from fire. Status - a perfect lawn is often equated with ones class.  Going back a century or so, if you had the resources to expend on maintaining a perfect lawn then one must be pretty well off.  

A pretty common sight: large lawns on multiacre lots.  

In his 1841 treatise on landscape gardening, A. J. Downing advocated for the need of having a proper lawn to have a tasteful and civilized property.  He translated the Romantic style of late 18th-century English landscape architects into a form more suited to the United States, particularly in the Hudson Valley and Mid-Atlantic.   Downing was extremely influential in setting the course for American landscape design into the 20th century.  Another key event in making the lawn a standard feature was around 1870 when the reel lawnmower, which had been invented in England, came to the US.  This made keeping a mown lawn more practical. 

Achieving the ‘perfect’ weed-free lawn was made much easier with the development and marketing of the herbicide 2,4 D (1944) for residential use.  A lawn treated with this was made free of nearly all non-grass (dicot) plants.  This meant that most flowering plants which could support pollinators (e.g. clover, fleabanes and heal-all) could be eliminated from lawns.  The result was a nearly flawless (one could say featureless) green carpet of only grass-like (monocot) plants.     

Considering the history of landscape design from earliest times, there seems to be a need for humans to exert control over nature, despite the costs.  People, in general, feel much more comfortable in a landscape that is readable or understandable.  These are places where they can see the ins and outs and how to move through the space.  Think of the composition of a photograph or painting.  There are elements that draw the eye through the piece to a focal point.  Crisp or well defined edges are also important in creating readability.  I’ll admit that I do feel a sense of satisfaction when I look back on an evenly mown and edged green carpet. 

Let’s look at some data about lawns in the United States:

Acreage of lawns   Looking on the internet I found figures of between 40 and 50 million acres of residential turf grass in the US.  Compare that to the total amount of land used to grow corn which averaged at about 90 million acres between 2018-2022 (USDA data).  These figures are based on satellite imagery.  Most corn is grown without irrigation.  If you compare the irrigated acreage for corn of about 12 million acres to that for turf, then you come up with 3-4 times as much lawn as irrigated corn. 

Amount of gas used   Based on EPA figures from 2005, 800 million gallons of gasoline were used to power lawn care equipment each year.  Using this weeks’ national average of $3.72/gal you are talking about $3 billion dollars annually.  On top of that, lawn mowers and other small-engine powered lawn equipment, which have no pollution control devices, are significant contributors to air pollution.  Estimates are that combined landscape care equipment contributes about 5% of the total air pollution, CO, hydrocarbons and NOx .

Amount of water used on residential landscapes   EPA estimates of water use for landscape purposes is 9 billion gals/day (WaterSense 2013).  Most of that is treated potable water that could be used for domestic consumption rather than poured onto the ground.  With the increasing severity of droughts, particularly in areas of the Southwest where population is shifting towards, there are very real problems with providing all the water that is needed. 

So considering that lawns and lawn care have increasing costs and negative effects it is time to ask why and how much lawn can we afford and what are the alternatives.

Trends away from lawns:

No mow May.  Started in England as a push to provide early season pollinators with flowers that are common in English lawns.  Blindly adhering to a no-mow-May program in a country with so many diverse climates and types of lawns as the US is often inappropriate.  To be useful, the lawn or property in question needs to have a population of plants with early blooming flowers that the pollinator population likes.   Depending on the climate the appropriate time for suspending mowing could be as early as February or into the later part of May.  If you have a monoculture of Kentucky blue grass there is little benefit to pollinators in skipping a month of mowing, there is just nothing of benefit there for them.  If you have a diverse ‘lawn’ containing native weeds like violets, self-heal (Prunella vulgaris), fleabanes (Erigeron sp.), spring beauties (Claytonia virginica) and the like, then allowing those to come into bloom would have a positive effect.  If you really need to mow, take the effort to mow around the blooming plants until they are done.  Lawns can also be interplanted with spring bulbs.  While not native, very early bulbs like Crocus, Chionodoxa and Scilla can add interest to an early spring lawn.  These bulbs have usually completed their growth and blooming cycle by the time the need for mowing kicks in.

I have been allowing this patch of Philadelphia fleabane
to develop without mowing.  It reaches peak bloom
in mid-May.  I usually mow it down in early June
after it sets some seed. When not in bloom plants survive
as low-growing rosettes.  

While there is the oft repeated advice to never cut more than one third of the length of the grass blade at a time, I rarely let that force me to cut the lawn before I’m ready.  I can’t say that I have ever noticed a problem by occasionally letting the lawn get too long between cuts.  In those cases when I do the biggest problem is the long clippings left on top.  A mulching mower can help deal with that.  All these problems are magnified on the ‘perfect’ lawn, where any imperfection becomes blaringly obvious.  In a diverse, multispecies lawn imperfections blend into the mosaic of plant colors and textures.

Lose the Lawn  This is a phase that is used by many people when voicing their concern about the amount of resources being pouring into and onto lawns.  You can get excellent advise on this subject for university extension services.  Doing an internet search on ‘lose the lawn’ and your state of region can give you information on lawn alternatives suitable for your area.  For example try this link to the UMD extension for the Mid-Atlantic region.

Climate appropriate landscaping   This is another phrase used when talking about more sustainable landscape practices.  Simply put, it is using plants that grow well with the resources that are naturally available.  Native species appropriate to the local climate require much less water and other inputs than turf or other non-adapted species.  When there are no plants suitable, look to using other materials to achieve the design goals.  It also means avoiding the use of plants and materials that require an extraordinary amount of inputs to maintain them.  

As droughts are becoming more frequent and severe, many municipalities are instituting water restrictions and/or offering enticements for installing water efficient landscaping.

What can one do?

>If you have a lawn, mow and water when lawn needs it, rather than on a preset schedule.  This can be difficult with lawn services since making a flexible schedule with multiple clients can be very difficult.  I did see on the web some services that offer options for having a less frequent mowing schedule.  That may be a move in the right direction.  In general lawns maintained at 3-4" have deeper roots making them less dependent on frequent watering.  Also the taller turf shades the soil which reduces weed seed germination and evaporation or soil moisture.

>Replace high maintenance lawn grasses with climate appropriate turf.  The US is divided into 3 zones for turf grass, cool season, warm season and the transitional zone between them.  A nice overview of turf grass types for the various regions of the United States can be found in this blog post from Landscape America.  While most turf grasses are not native to North America a few are.  Buffalo grass (Bouteloua dactyloides) is a native species found in the plains from Southern Canada to Northern Mexico.  It has been developed as a drought tolerant turf grass.  A native of the Gulf States, St. Augustine grass (Stenotaphrum secundatum) has been cultivated and planted along the east and west coastal areas of the US.  Fine fescues are well adapted to the Pacific Northwest and Northeastern states.  A few subspecies of red fescue (Festuca rubra) are native to North America; however, the blends suited for turf usage contain a variety of fine fescues most of which are not native.  There are at least three blends of these fine fescues that have been selected for use in cool season growing zones that are drought tolerant, need little fertilization.  Look for Eco-Lawn, Eco-grass or No Mow fine fescue blends. 

This patch of lawn is mostly fine fescues that is mown about every two weeks. 
It looks like regular 'grass'.  If I did not mow it it would would develop a
 fine silky, mounded texture that fine fescues are noted for.  

>Develop a tolerance for having mowable green, rather than a perfect cloned lawn.  My lawn, in the Mid-Atlantic region, is a mixture of tall and fine fescues, nimblewill (Muhlenbergia schreberi, a local native species), probably some purple top (Tridens flavus, also native), violets, fleabanes, clover and some less desirable (but tolerable) weedy stuff.  A diverse lawn requires fewer inputs to maintain.

>Consider alternative ground covers.  Regionally native species are preferred because, in addition to requiring little to no mowing, they also support local wildlife.  Some lower growing North American natives that can replace, or be incorporated into a lawn include frog fruit (Phyla sp.); pussy toes (Antennaria sp., for sunny dry conditions), and golden ragwort (Packera aurea, partly sunny, moist conditions).  Moss is perfect for a shady spots. Again, doing a search on ‘lose the lawn’ coupled with your region yields results that offer a list of alternative ground covers.  I recommend focusing on web sites managed by university extension services as providing the most unbiased results.

This patch of golden ragwort bursts into bloom in April. 
It is semi-evergreen and grows to about 6" tall.  It is slowly expanding,
but can be kept under control with mowing.

>Reduce or eliminate fertilization.  In many situations it is a vicious cycle.  Fertilizer is needed to replace the nutrients removed when grass clippings are removed while mowing.  Then, the more fertilizer you add, the more the lawn grows, then the more there is to mow.  By leaving grass clippings in the first place and mowing in the leaves in the fall, you are recycling the nutrients in place and feeding the microbes living in the soil.  Using a mulching mower will reduce the amount of clippings visible on the lawn.

>Reduce area committed to lawn and replace with bedding, meadow-type plantings, successional plantings, or cropping (hay fields).  When reshaping the lawn, go for simple shapes that can be mown efficiently, avoid tight turns and acute angles.  I have one triangular area that requires a lot of backtracking to mow.  A rectangle or oval could be done with less backtracking. 
A successional planting builds on the natural process of succession.  Succession is the natural process where the mix of plants on a site changes over time, and it begins when one stops mowing.  East of the Mississippi River, the sequence is usually bare land becomes grasslands, which in turn becomes shrublands which eventually turns into forests.  This process usually takes many years.  The land owner could  speed up the process by planting desirable shrubs and trees to create an idealized version of the natural landscape.  Intervention by the landowner can also pause succession at various stages such as as a meadow or shrubland.

Here is a possibility of allowing some succession of  local native species
(redbuds, dogwoods, asters, etc.).  Clean edges and sightlines to and
from the dwelling confer intention to the landscape.  This more
diverse landscape offers much more to the local ecology. 

>When creating a new space, clean edges, whether straight or curved, convey a sense of intention in the landscape.  A wilder space surrounded by a clean edge is visually more comforting than a totally wild area.

>Where climate is not suitable for growing plants, use hardscape or inorganic mulches. Hardscape does not have to be impermeable concrete.  Dry laid stones and pavers allow for water infiltration which reduces runoff problems.

>Be creative with the space, put in artwork to fill the space and send a message.  On a recent trip to Sebastapol, CA we visited Florence Ave where many of the residents have sculptures in the front yards by local artist Patrick Amiot. 

This owl sculpture is complemented by a variety of
perennials in this lawn-free front yard.

The minimal landscaping around this catfishing dog works quite well. 
The colors of the spiky New Zealand flax play well with the colors in the statue.

Reducing the area committed to lawn does not have be be done all at once.  It can be done one area at a time, or by expanding planted beds or wilder areas a little bit each year.  I would love to hear about your experiences with reducing resources committed to maintain a lawn.

Wednesday, September 21, 2022

Stilt Grass: Discovery

I write a lot about dealing with Japanese stiltgrass, Microstegium vimineum.  I do really feel like I am making progress, but the  work is very tedious and the rewards are often delayed.  One way that I've been getting more immediate gratification is to watch for new plants discovered under the (hopefully decreasing) cover of stiltgrass.  Sometimes I'm finding new plants, but also finding increasing numbers of desirable species is a huge boost.  

Two new species for me this year are downy agrimony, Agrimonia pubescens, and whitegrass, Leersia virginica.  The agrimony was growing on the shady edge of a woodland that had been treated with a preemergent herbicide for a couple of years followed by some maintenance pulling of the stiltgrass.  The wands of bright yellow flowers made me think of a short goldenrod, but seeing the distinctly divided leaves led me to focus on some species of Agrimony. The form and small size of the seed pods, shape of the stipule and the hairiness of the stem confirmed the identity as downy agrimony, Agrimonia pubescens.  I hope to see more of this in the coming years. (I will skip using the preemergent in this area next spring.)  I found the Minnesota Wildflowers site to be very useful in identifying this species.  What was very useful was that it had photos of the same plant parts for each species.   

Downy agrimony blooming in August
at the edge of the woods.

Agrimony can be spotted by their distinctive divided leaves and
sharply toothed leaflets.  If I had just seen the three terminal leaflets,
I would have thought of some weedy potentillas, like mock strawberry.

The stipules of downy agrimony are a key feature of the
species, sharply lobed and distinctly divided.

The whitegrass almost got pulled, as on first seeing it I thought it was a tall mass of stiltgrass growing in the middle of the woodland.  As I got closer I could see that the leaves lacked the silvery mid-rib of stiltgrass and the leaves were narrower.  Also the flowers were small and white, not the buff color that I typically see with stiltgrass.  While I did not key out this grass I am pretty sure that it is actually whitegrass and a welcome addition to the woods.  If this catches hold though I will need to be more careful not to pull it as I am ripping out handfuls of stiltgrass growing nearby. 

The white flowers of whitegrass are pointed out here. 
Also note the long slender leaves.  This perennial grass
 is more strongly rooted than the annual Japanese stiltgrass. 

Here I'm holding some stiltgrass (Microstegium)
 next to the native whitegrass.  Note the broader
leaves and silvery center vein of the stiltgrass.

Some other plants that I am seeing more of this year include the native annual sweet everlasting, Pseudognaphalium obtusifolium, growing on a sunny edge of a mown pathway, more and larger masses of panicled tick-trefoil, Desmodium paniculatum, and more instances of what I believe are wood ferns, probably Dryopteris intermedia.

Panicled tick-trefoil tends to grow well in the midst
of meadow grasses.  This puts if at risk of being pulled out
when going after stiltgrass.  It is saved by its plentiful
purple flowers. Shown in the inset are its trifoliate leaves

I think this is intermediate woodfern, Dryopteris intermedia
I usually like to see what the sori look like to do an ID,
but this plant didn't have any. In general I'm seeing an increase
in ferns, this may be as much due to cutting back the wineberry
in the spring reducing as it is pulling out the stiltgrass.

Of course not every new thing is good.  I also found my first instance of wavyleaf basketgrass, Oplishmenus undulatifolius.  While I was not happy to see this, it good that I did and could rip it out immediately before this very invasive grass could get a foothold.  According to the SEEK app sightings of this grass are uncommon this far west in Maryland.  To report this I downloaded the MAEDN app, an app for reporting sightings of invasive species in the Mid-Atlantic region.  This app can be used for all types of invasive species including the spotted lantern fly.

At first I though that this looked like a variant of deer
tongue grass, with crinkled leaves, but on a second
look the way that the leaves were attached and the growth habit
were very different.  The 'SEEK' app quickly ID'ed this as
wavyleaf basketgrass, a recent and very serious invasive species
in the Mid-Atlantic region.

Patrolling the woods for stiltgrass also is an opportunity to identify and remove seedlings of other invasives that were hidden under the stiltgrass like burning bush, bush honeysuckle, barberry and autumn olive.

Monday, August 15, 2022

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






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


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


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.

Saturday, July 2, 2022

Smooth Hydrangea

 Smooth hydrangea, Hydrangea arboescens, is a North American native shrub with a native range is from New York and Massachusetts, south to Florida and west to Oklahoma and Kansas.  In the wild it is found in dry to moist woods and hillsides.  I thought that the name Hydrangea referred to it growing in, or preferring wet areas.  In fact, the name refers to the shape of its seed capsule which resembles that of a water vessel, a hydriai, in Greek.

Here's an example of wild type of smooth hydrangea growing along the
Potomac River near Sharpsburg, MD.  This photo was taken in mid-spring. 
I was surprised to see that flower buds had already formed.   

I really like this plant for landscaping purposes, particularly in the colder regions.  Unlike many of the blue and pink bigleaf hydrangeas (H. macrophylla), which bloom on year-old stems, smooth hydrangea blooms on new wood.  So whether you prune it or not you will reliably get blooms.  Also there is no need to protect the plants from winter cold.

This shrub grows really well in shade, in average to moist soils, and will tolerate sun if provided consistent moisture.  It is also tolerant of juglone produced by black walnut trees.  This makes it an excellent choice for growing under the canopy of walnuts and hickories.  Depending on how and when you prune them smooth hydrangea grows as a mounding shrub 3-5’ tall and wide.  Flower types are either mophead, large balls of mostly sterile flowers, or lacecap, flattish inflorescences of small fertile flowers surrounded by a rim of larger sterile blooms.  One drawback to smooth hydrangea is that, at least in my area, deer really like to eat the leaves.  I’ve found that surrounding young plants with chicken wire cages and using deer repellant on larger plants are sufficient to allow the plant to survive deer browsing.  Another problem, particularly with the large-flowered cultivars, is flopping.  I help support them by running a matrix of strings about 30" off the ground around and between 5 or 6 posts.

Here's a mass of the 'Annabelle' cultivar a couple of days after
a heavy June rainstorm.  Once the large blooms dry out,
they usually bounce back up.  

At the end of May flower bud formation is well underway. 
This is the stage when I will selectively cut back the taller, bud-bearing stems
by about a foot, just above the leaf  node.  This will lead to a
second flush of flowers in late summer.

My usual maintenance routine starts in early spring when I cut all the stems back to 1 or 2 pairs of viable leaf buds.  This will give me a rounded mass about 3-4 feet tall.  (Unpruned, they would grow to 5’ or more.)  When flower buds begin to form in mid spring I cut  about half of the tallest stems by about 1/3.  This will give me a second flush of flowers in mid to late summer, as the first set of blooms are fading.  I usually leave most or all of the stems in place through the winter since the dried up flower heads still have some interest.  Also some bees are able to use the cut stems as nesting sites.

A typical mophead inflorescence of  an 'Annabelle' hydrangea. 
This one is about 9" across. The large sterile flowers start out
greenish white, then become white as they fully open. 
A very few fertile flowers are buried in the center. 

 ‘Annabelle’ is the most widely known cultivar.  I was discovered in the wild in 1910 by Harriet Kirkpartick in the woods near Anna, Il.  It has a large white mophead inflorescence of mostly sterile florets.  They maintain their appearance for 6-8 weeks.  They age to a straw color that is also attractive.  These flowers can be dried and used in arrangements for several months (sometimes years).  As I have become more aware of how our landscapes affect nature I’ve decided to try to broaden the selection of smooth hydrangea and include some more ecologically useful species and cultivars.  In particular I wanted ones that would support pollinators.

Recently the Mt. Cuba Center published an exhaustive trial of smooth hydrangea cultivars and related species.  In addition to the horticultural aspects this trial looked at the number and types of pollinators that visited the flowers.  Not surprisingly, the lacecap types, both wild type and cultivars, had at least 3 times as many insect visitors as the ‘Annabelle’ cultivar.  Two years ago I planted some quart sized lacecap ‘Haas Halo’ cultivars.  This year they are producing large blooms.  

Here's a photo of the lacecap type of flower, this one is from the 'Haas Halo' cultivar. 
Note that the middle of the inflorescence consists of fertile flowers,
 evidenced by their erect stamen.  The large white flowers along the rim are sterile.   
On closer examination you can see that there are also a variety of insects
on the fertile flowers, collecting nectar and pollen.

This year I’ve also added a wild-type plant.  I don’t know exactly what this will look like when it blooms, but in general these carry much less visually impressive flowers (to humans) but provide a good source of pollen and nectar for the insects and a big increase in genetic diversity for any seeds that may be produced. 

So if you are looking for a medium sized native shrub that blooms in shade take a look at smooth hydrangea, especially the lacecap types that offer a little more back to your wildlife.


Sunday, May 22, 2022

Living Mulch

Mulching garden beds has been a consistent ‘must-do’ for many gardeners.  Mulching reduces moisture evaporation, suppresses weeds, adds nutrients to the soil, reduces erosion and in many cases improves moisture absorption. Wood and bark chips are the most common materials employed.  Recently I have seen and read more about the negative effects of wood chip mulches. In particular when these mulches are over applied and allowed to compact, they can actually retard rain water absorption.  Thickly applied mulch can retard the growth and expansion perennials.   In his book The Know Maintenance Perennial Garden, Roy Diblik discusses how unnatural wood chip mulch is.  In areas that get adequate rainfall to support a tight matrix of plants, a living, or green, mulch is the ideal.

For many sustainable and naturalistic gardens the goal is to create this ‘green mulch’ or ‘living mulch’ by filling the space between garden features or larger plants with more plants.  ‘Green mulch’ is living plant material that performs all the functions of wood mulch such as weed suppression and soil moisture and temperature moderation.  In addition properly selected green mulches offer additional benefits like supporting wildlife and insects with food and cover, lower maintenance (since they do not to be replenished or broken up on a regular basis).  This green mulch may be a single species or a variety of plants that form an interlocking matrix. This matrix is most like what you would encounter in a meadow or woodland setting.

An example of a classically mulched bed. 
Each plant is distinctly identifiable and  there are no
random plants to confuse the composition.
One problem with green mulches is that they can look weedy due to lack of readability, no clear design or cluttered appearance.  Many folks are more comfortable with a landscape or garden where the features are clear and recognizable.  Having beds with clean edges is a quick way to make a garden more legible.  This human desire for legibility is also seen in the preference of many for plants neatly separated by oceans of mulch. 

One means of creating a green mulch is to install plants closer together so that they quickly grow together to create a continuous green carpet of foliage. This is one of the themes of the book New Naturalism, by Kelly Norris, published in 2021.  The trick here is to create plant communities that a good match to your site conditions and that the plants play well together. 

An example of a green mulch.  Creeping phlox, Phlox subulata,
and wild strawberry, Fragaria virginiana, have grown together
 to form a 4-6" deep ground cover.  Shrubs and perennials,
like the wild geranium, Geranium maculatum, here,
 are able to grow through.

Another route to a green mulch is to plant lower grow species as a matrix between your feature plants.  The trick here is to keep your garden readable so that the matrix does not obscure your design intent.  By way of example consider what bindweed does to a garden.  While it grows quickly to fill all the voids in the garden it also grows up and over taller plants resulting in tangle of plant material that has no discernible form, no starting or ending points and little textural contrast. (Kudzu does this on a much larger scale, draping a woodland edge with green vines, effectively removing all contrast between the trees.)  Consider instead a perennial bed where the spaces between plants are filled with low growing violets.  The glossy round leaves of the violets don’t interfere with the forms and textures of taller perennials or shrubs.  A list of some of the lowest growing  Mid-Atlantic natives includes:  Pussytoes (Antennaria sp.), wild ginger (Asarum canadense), Green and Gold (Chrysogonum virginianum), wild strawberry (Fragaria virginiana), barren strawberry (Geum fragarioides), Meehan’s mint (Meehania cordata), partridgeberry (Mitchella repens), golden ragwort (Packera aurea), various species of phlox (Phlox divaracata, stolonifera or subulata),  foamflower (Tiarella cordifolia), common violet (Viola soriana),  and  short sedges like rosy and ivory sedge (Carex rosea  and  C. eburnea ).

Golden ragwort is excellent native ground cover.  It spreads rapidly
 in moist, partly sunny locations.  It also seems to suppress invasive
 weeds like Japanese stilt grass and garlic mustard.


Using spring ephemerals for this purpose is a very natural means of creating a matrix.  These perennials naturally flourish early in the year when tree and shrub canopies are open, then slowly go dormant as the canopy closes up.  They return again the following spring.  In the Mid-Atlantic you may find Dutchman’s breeches and squirrel corn (Dicentra sp.), mayapple (Podophyllum peltatum)  and Virginia bluebells (Mertensia virginiana)  as common examples of these.  A limitation with using ephemerals is that they do totally disappear after setting seed.  They are ideal in an established perennial or shrub bed where you just need something in early spring while the larger plants are leafing out.  

Ephemerals, like cutleaf toothwort, Cardamine concatenata (in bloom),
 and Dutchman's breeches, Dicentra cucullaria, fill out in early spring.
but disappear as the tree canopy fills in. 

Using short-lived species that survive primarily by reseeding is another means to establishing a sustainable living mulch.  By nature these are opportunistic gap fillers.  As the longer lived perennial and shrub layers get established these reseeders tend to be squeezed out as their preferred, open habitat disappears.  Yellow fumewort (Corydalis flavula), American pennyroyal (Hedeoma pulegiodes), common yellow woodsorrel (Oxalis stricta), and self-heal ( Prunella vulgaris) are some of the shorter species that can be used in this way.  Taller, showier species that can be used as temporary gap fillers include wild columbine (Aquilegia canadensis), Partridge pea  (Chamaecrista fasciculata), fleabanes (Erigeron annuus and E. philadelphicus), and black-eyed Susans (Rudbeckia hirta).

Wild columbine, growing about 2' high, is relatively
 short lived in gardens due to competition and rich soils.
It produces a lot of seed so that it can reappear in other suitable
 locations where seeds can make soil contact and
have access to sunlight. (unmulched areas).

Yellow wood sorrel is considered a weed in many cases.  However,
 this native plant satisfies the requirements of a living mulch quite well. 
It grows quickly and produces lots of seed to fill gaps, is relatively short lived,
and is easily displaced by larger plants. As a native it also supports wildlife,
 particularly bees and birds.  Its lax, floppy habit detracts from it appearance,
making it appropriate around much larger plants and shrubs
or where this flop is not a distraction.

Oxalis stricta is very similar to its European relative, O. europea
Each has the same common name, common yellow woodsorrel. 
The North American species can be distinguished by the horizontal
disposition of the seed stalks (indicated by arrow). 
O. europea has seed pods on ascending stalks.

So if you are willing to give up the repetitive chore of mulching your garden beds, consider having your plants do that job for you and establish a living mulch.