Archive for the 'invasive' Category

Walking the Walk | Becoming Green


I went to a spectacular lecture today at the U. S. Arboretum.  I found out about it because I recently joined the Arboretum as a Friend for the mere pittance of a $35 contribution.  I encourage all my buddies out there to join and attend some programs with me.  This was the program I saw.  Below the announcement, I have written up some notes to share about some pretty exciting advancements in

Measuring Sustainability in the Garden

Dr. Steven Windhager

There is a great deal of talk about creating sustainable gardens, but how do we assess the level of sustainability in a garden? The SSI (Sustainable Sites Initiative) has been formed to provide guidelines and performance benchmarks for those who want to create and measure sustainable landscapes. The goal is to quantitatively asses the attributes of all types of sites in order to measure success in maintaining or improving the health of an ecosystem. Learn about the SSI, including what it is, why it is needed and how it affects public gardens and other landscapes.

Dr. Windhager is the director of the Landscape Restoration Program at the Lady Bird Johnson Wildflower Center and serves on the Steering Committee and as Technical Advisor for the SSI. His expertise includes Sustainable Site Design, Ecological Restoration, and Urban Ecology.

Lecture Notes |

On average, 30 to 65% of a family’s daily potable water is used in landscaping (what a bummer to learn this!).  Strategic planting of 1 canopy tree can eventually conserve 25% of a home’s energy use.  We all need to think macro in order to make actual gains in living greenly.  Conservation is all well and good, but, we have the opportunity to reverse some of the detrimental impact we’ve had on our own environment in terms of climate change by designing “sustainable” landscapes, big and little.

To achieve true sustainability, we must satisfy 3 intersecting criteria: economic vitality, social acceptability, environmentally sound science.  In other words a yard needs to be affordable, look great and add up to a sum gain in energy use when you consider ALL factors in it’s creation and care.  He gave the example of a commercial property where a pond for storm water abatement is put behind a building and fenced off with ugly chain link.  While this pond may, at first, do it’s job, it’s been shown that it is soon ignored and then not maintained properly, falls into dis-repair and soon enough is no longer effective.

So it’s important to measure carefully and precisely.  That’s where the Lady Bird Johnson Wildflower Center came in.  Maybe a decade ago, they wanted to become LEED certified (Leadership in Energy and Environmental Design), but there they found there were no benchmarks for landscape design similar to those developed for architecture and building.  So they began working on guidelines for sustainable methods and benchmarks for performance in landscape design.  The Sustainable Sites Initiative, a system where “credits” are appointed for design that meets particular criteria (available at  They encourage design that for example, uses very little or no potable water for irrigation (only gray water like captured A/C condensation) and keeps storm water from ever running off a site and much, much more.  They even give credit for plastic pot recycling programs.  This initiative also shows how to measure sum gains realistically.  Dr. Windhager spoke a lot about assessing the starting point of any site.  Is it a ‘Green”, “Grey” or “Brown Field”?  A Green Field describes a site that has no previous building on it.  A Grey Field is a site that has had building but is not contaminated with any toxic chemicals, and you can guess what a Brown Field is.

He also said that the costs of sustainable design are front loaded in the design phase, but can often be built for less.  He recommends that every project include a Soil Plan that addresses potential compaction, how it may be mitigated or how bulk density may be restored and to bring organic matter to acceptable or improved levels.

The guy was a wealth of knowledge in this realm and explained everything clearly.  If you ever get a chance to hear him speak, please do.  One of his most potent pieces of advice:  Never Ever Use PEET.  It traps too much carbon in the soil.  Enjoy.

Creating Balance on a Hill | dogwood*design project



Adele Medina O’Dowd, principal, dogwood*design, llc
contact me | or 202.255.0728
references available upon request


This project in NW DC is not yet finished though like many, these clients wanted to accomplish it in phases.  For phase 1, the main ideas were to connect the hill to the house and establish a new order by clearing that invasive ivy and the overgrown azaleas, and by adding some “infrastructure” to support the visual and actual weight of the earth on the steep slope.  Adding to this issue, because of the steepness of the slope and it’s disconnection to the hill, the house appeared to be “floating”, overbearing and unfriendly.  We did not need to start from scratch with the entire front yard since many of the foundation plantings close to the updated Tudor house remain appropriate in size and will be fine to “build” upon.  But the hill itself was an unruly mess that could not be reckoned with, until it could be reconceived and reworked.


Besides clearing the hill of ivy and other unattractive shrubs, I added low stacked stone walls working around an existing dogwood near the bottom of the front steps and an new crepe myrtle at the top right.  The walls  serve as terraces in which to plant.  I also recommended to the client that we add a couple of larger scale boulders on the hillside, espcieally near the stairs, but she elected not to do this.  We added several winter jasmine, cranberry viburnum and liriope (see images below) planted in November to get established before winter.  We also installed a large American Holly in the foundation planting bed to make the planting more dynamic next to the house.  In the next phase coming in spring, we’ll be adding low weeping yews (Taxus baccata Repandens), dwarf fothergilla, red stem dogwood, and oakleaf hydrangea.  In to the future and over time, the homeowner will do some planting herself, planting woodland perennials that I’ve chosen for her, such as Heuchera, Bleeding Hearts, Coreopsis, Tierella and Hakonechloa Grass.

BEFORE (Below) The front stairs had been newly built by another contractor — and are certainly attractive — but were not integrated, visually, with the house or the yard.


AFTER Now (below), the new low stacked stone “walls” visually marry the house to the hillside, taking advantage of relationship of the stone in walls and stairs to the (existing) stone entryway.  The new walls also provide horizontal lines in the view of the house, adding to the perception that the house is now better grounded.


Looking closely at the photo above.  You can also see a handrail, actually made of old plumbing pipe.  This is another change that desperately needs to be made.



Stay Tuned for the exciting conclusion.

This is the master plan for the front yard

This is the master plan for the front yard

SCARY | invasive grasses of the Mid Atlantic

Oh no!!!!! This calls for lots of exclamation points. Please don’t use these invasives. They ARE attractive, but the typical Zebra Grass (aka Chinese Silver Grass) is invasive in the Mid-Atlantic:
Miscanthus sinensis ‘Little Zebra’
Miscanthus sinensis Anderss
Miscanthus sinensis, the species

check it out…

Other bad boys include:
Pennisetum alopecuroides
Pennisetum alopecuroides ‘Hamelm’

Alternative non-invasive grasses include:

Carex grayii and other sedges [native = bonus points]
has amazing medieval looking flowers

Molinia caerulea
Digging Dog Nursery has a good selection

Muhlenbergia capillaris

Panicum virgatum ‘Cloud Nine’ [native = bonus points]

Panicum virgatum ‘Prairie Fire’