Thursday, June 16, 2016

Finding a mate for my Plants, part 2

One of my goals in creating a more wildlife friendly landscape is to use plants that produce fruits and berries in addition to pollen, nectar and habitat.  While for some plants that is not a big deal.  A single specimen may be self fertile, or there are other nearby plants for cross-pollination.  Where I have been having more trouble is with some of the less common species to my neighborhood.

A good number of fruit bearing trees and shrubs are dioecious, that is, they have male and female flowers on separate plants.  You need one of each in order for the female to bear fruit.  The classic example of this in horticulture is with the hollies (Ilex sp.).  Fortunately, the industry knows that customers expect to see red berries on their winterberry hollies, so they have provided distinctly named male cultivars to interplant with the more attractive females.  Usually one male plant is sufficient to fertilize five females. 

Finding information on the genders of other plant species is more challenging.  Many maples are dioecious, but it is rare to find its gender in the plant description.  Most folks don't care much about the flowers on a maple, they are too far away to see and the foliage is the main feature anyway.  However gender is an issue for many allergy suffers.  Male trees produce loads of pollen and if it's wind borne, that's a lot of pollen in the air.

This Sassafras was blooming at the beginning of April.
Males have showier flowers because of all of the stamen.
The female flowers are more subdued.
My goal is to have mating pairs so that I can get fruit production for the birds and other wildlife.  On my property I have a number single specimens.  In order to find out which genders I have, I need to be out there observing them while in bloom.  I learned that my big sassafras tree is a male since I was out there in early spring while it was blooming.  I didn't see any others in bloom.  I recently purchased a new seed grown sassafras, but it will be maybe 10 years before I learn its gender. 

One approach to getting mates when buying young plants is just to buy a lot of them and then play the odds.  I often buy 3 at a time, but 5 gives you a better shot. This is only certain for seed-grown plants.  Plants propagated from cuttings will have the gender of the 'parent' plant.  Then you need to hope that the propagator started from a mix of plants and not a single cultivar.



This fringe tree is probably 4 years old and
has a few blooms on it.


Another approach is to be at the nursery and find plants in bloom.  I got lucky this year when I found small fringe trees in bloom at my favorite nursery.  I went home and saw that both of mine were also in bloom and they were both females.  I headed back to the nursery and looked though their plants until I found a male and bought it.  Now I'm all set for next year.

This is the female flower, there are two stigma held closely in the center.
The male flowers have two paddle-shaped anthers that protrude from the flower center.

Tupelo, Nyssa sylvatica, is another tree that is dioecious.  I put in two of them in a couple of years ago.  Then I realized it was a big gamble that I would have one of each, so a added a third this year.  These mature into fairly large trees, so I don't want to fill up the yard with a bunch of them.

I have a mature persimmon tree that is female.  The first year we moved here I added 5 more saplings.  Now, 4 seasons later they are about 10 feet tall, but still no sign of blooming.  Maybe next year.

Here's the female persimmon in bloom.  I haven's seen what the male looks like, yet.


The native pussy willow (Salix discolor) also comes as separate male and female plants.  The male is showier with its large fuzzy stamen.  These plants do bloom when they are small, so you might have luck determining which to buy at the nursery.  These bloom in mid-April around here and, unfortunately, many nurseries aren't open for business then.  The one I purchased two years ago was male.  Willows are very easy to propagate by cuttings.  So I was able to quickly grow several new plants, but these will all be male.  I did pick up another this spring, but it was not in bloom.  The vendor said it was seed grown so I'm working blind.

The male flower of this pussy willow is adorned with bright yellow stamen.
The flowers on female plants are green and somewhat scaly in appearance.

I did get a couple of goatsbeard (Aruncus diocus) which turned out to be both male.  This is a case where I am happy not to have a mate.  The male has the showier flower and two plants take up more than enough to space in the garden.
The stamen on these male goatsbeard flowers really catch the light.

Monday, May 9, 2016

Which is the Strawberry?

I am adding a number of Virginia strawberries, Fragaria virginiana, to my gardens this year.  This is part of my plan to incorporate more edible plants, particularly natives, into the landscape.  While I may not get many berries from these little plants this year, I expect to get a harvest next year after the plants have settled in.  One important thing that I will need to learn is how to tell these fruit bearing plants from the insidious mock or Indian strawberry, Duchesnea indica, that is growing just about everywhere on the property.

Here is mock strawberry with its bright yellow flower
and trifoliate leaves.  These leaves are evergreen here in zone 6.

Indian strawberry is an exotic species from southern Asia imported to the US as an ornamental plant and has widely naturalized over the years.  The 'Indian' in the name refers to a region of Asia, not Native Americans.

Both plants have similar trifoliate leaves with bluntly serrated (toothed) edges.  They each form tight clumps of basal leaves, spreading by above ground runners.  Also, they each produce bright red fruits with seeds on the surface.  The most obvious difference is the flower color, Virginia strawberries have white, 5-petaled flowers, while those of mock strawberry are bright yellow.

This newly planted Virginia strawberry has not settled in enough to flower.
The leaves are persistent through the winter, but these will turn red,
adding to winter interest.

Another difference is in the fruit.  The seeds of Virginia strawberry are located in depressions on the surface of the red 'berry'.  Mock strawberry seeds are actually in projections above the fruit's surface.  Also the fruit from mock strawberry is dry and tasteless compared to the sweet, juicy fruit from the Virginia strawberry.


These differences make it easy to tell the two plants apart when they are in bloom or fruit, but what about the rest of the year.  I was looking for a definitive feature to rely on.  Many times botanical descriptions depend on doing a comparison, e.g. more or less hairy, or 'broader' leaf.  I was looking for a yes or no test that I can use quickly while pulling weeds.

Here are both surfaces of the leaves of mock strawberry.
The arrow at left points out the longger terminal tooth.
So while the leaves of mock strawberry are more coarsely serrate and its veins are more divided than those of Virginia strawberry, the more practical method for me is to look at the tip of the leaf.  On nearly every leaflet of mock strawberry the  terminal tooth is longer than the ones on either side.  For Virginia strawberry the terminal tooth is shorter the its neighbors.  Maybe after working with the Virginia strawberries for a season or two I will appreciate the finer differences.  For now the goal is to not pull up any of my new plants.

Here are both leaf surfaces of Virginia strawberry.  Again,
the arrow points to the terminal tooth on the leaf, which is
distinctly smaller than its nearest neighbors.

Monday, April 11, 2016

New Plants for 2016

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

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

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

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

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

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

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

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

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

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

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



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




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



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

Now I just need to get to work!

Monday, March 7, 2016

Goals for 2016 season



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



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

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

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


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


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

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






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


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

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

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





Monday, February 15, 2016

Native Plant Information on Houzz

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

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

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

Here are links to a few of my articles:

Thursday, January 7, 2016

Mystery Solved! Unknown Fern Identified!

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

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

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

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

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

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

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

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

Tuesday, December 1, 2015

Fall's Second Season

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

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

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

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



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




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




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




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



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


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