Welcome to VDC Green!

This blog was born out of our passion for "green" design, our continual pursuit of new innovative sustainable technology, and our commitment to learning and growing as professionals. We will be researching and discussing a new topic related to sustainable practices frequently, so check back with us often.

We hope this blog provides you with some useful knowledge, maybe a little inspiration, and a lot of fun!

Monday, October 18, 2010

Soil Stability

Soil health and stability is crucial in intense Urban environments to be able to provide proper strength above for whichever paving system is utilized, while at that same time preventing compaction of the substrate where tree root growth is crucial for the long-term success of urban plantings.

Soils under pavement need to be compacted to around 95% density before pavements are laid in order to meet most load-bearing requirements for pedestrian and vehicle use. This compaction causes restricted growth of the tree roots beyond the tree well, thus causing the tree health and growth to suffer.

Recently, Vision Design Collaborative hosted a lunch & learn on the Deep Root Silva Cell product – an engineered structural cell that helps provide available soil, root, and utility space while providing structural support above for paving.

Energized by the lunch & learn we wanted do a little research on various alternatives for soil stability, which can be used in urban environments to help ensure the success of plantings & pavings. We are going to explore 3 approaches:

Photo: Copyright Permatill

1. 1. CU-Structural Soils

2. 2. Suspended pavement

3. 3. Sand-Based Structural Soil

CU-Structural Soils

CU-Structural Soil is a mixture of crushed gravel and soil with a small amount of hydrogel to prevent the soil and stone from separating during the mixing and installation process.

CU Structural Soil uses a carefully chosen aggregate with the proper stone to soil ratio which creates a medium for healthy root growth that can also be compacted to meet engineers’ load-bearing specifications. The proportion of soil to stone is approximately 80% stone to 20% soil by dry weight, with a small amount of hydrogel aiding in the uniform blending of the two materials. This proportion insures that each stone touches another stone, creating a rigid lattice or skeleton, while the soil almost fills the large pore spaces that are created by the stone.

The intention is to “suspend” the clay soil between the stones without over-filling the voids, which would compromise aeration and bearing capacity. This way, when compacted, any compactive load would be borne from stone to stone, and the soil in between the stones would remain uncompacted.

References: 1.The great soil debate – ASLA 2. Urban Horticulture Institute – Cornell University

Suspended Pavement

Suspended pavement involves using a modular building block for containing unlimited amounts of healthy soil beneath paving while supporting traffic loads and accommodating surrounding utilities. The engineered building block is filled with high-quality, uncompacted soil to grow trees and manage the rate, quality and volume of stormwater. The modular system can be easily sized to accommodate the needs of any site without compromising effectiveness or site design.

Photo: copyright DeepRoot Silva Cell
The use of structural cells solves the limitation of soil volume by placing a structure that supports the pavement above, allowing a much larger, low compaction soil volume for tree root growth. Without having to respond to the structural requirements of the pavement, the soil is free to meet the challenges of providing the tree with excellent water holding capacity drainage, fertility and long term soil biological functions. The soil, protected within the cells from compaction, can then support bulk densities that are ideal for tree growth.

Photo: copyright DeepRoot Silva Cell

A suspended pavement system integrates trees and soil with stormwater management, utilizing the proven capacity of soils to act as an underground bioretention system. Through soil filtration, bioremediation and evapotranspiration, this system can treat stormwater directly on-site

References: 1.The great soil debate – ASLA 2. DeepRoot Silva Cell brochure

Sand-Based Structural Soil

Sand-Based Structural Soil (SBSS) is a comprehensive system designed to create natural, sustainable growing environments beneath pavements. It provides an appropriate rooting medium for trees which can also support pavements. A typical profile consists of pavement, underlain by several inches of crushed stone, underlain by two to three feet of sand based structural soil, underlain by a drainage system. Aeration pipes are placed within the crushed stone layer to create an air/soil interface at the top of the structural soil. An irrigation system, typically drip irrigation within the aeration pipes, or harvested stormwater distributed though the aeration pipes, provides moisture and nutrients as needed.

Photo: The great soil debate – ASLA

The uniform gradation of the sand allows for a high degree of compaction yet bulk densities remain low and particles cannot pack into a hard mass. Excavations near street trees planted in SBSS have shown rapid root growth into the soil medium. Installations throughout the United States have demonstrated that SBSS supports pavements without settlements, yet is readily penetrated by plant roots.

Stormwater harvesting can be used with slot rains or catch basins. Collected water is distributed through the perforated aeration pipes. High rates of inflow cannot saturate SBSS soils and good aeration ensures a soil environment where aerobic microbes can thrive.

References: 1.The great soil debate – ASLA

Photo: The great soil debate – ASLA

Friday, September 10, 2010

Permeable Pavement Systems

Just recently, VDC hosted a lunch & learn at their office in downtown Asheville, showcasing Belgard paving systems. The main topic of the presentation was Sustainable Site Design & Stormwater Management with Permeable Pavement Systems and there was some great information on paver systems. Below is a general overview of what pervious pavement is, its benefit and several types of systems used today. There is also some great information related with permeable paver systems such as freeze thaw, maintenance & life cycle cost comparisons located here: http://atfiles.org/files/pdf/PermPavers.PDF

Pervious pavement is designed to allow percolation or infiltration of stormater through the surface into the soil below where the water is naturally filtered and pollutants are removed. This helps promote growth in trees and flower beds that are near the system. In addition to these benefits, it also cleans the water that drains into the natural waterways of our cities and neighborhoods and in some cases it can be used to help reduce the amount of stormwater retention and drains throughout a city by reducing the total volume of stormwater runoff and helping to remove the oils, fuels and other contaminants that are normally picked up by water on its way through the streets.

In contrast, normal pavement is an impervious surface that sheds rainfall and associated surface pollutants forcing the water to run off paved surfaces directly into nearby storm drains and then into streams and lakes.

These contaminants can kill not only vegetation throughout the city, but wildlife that drinks from the streams and rivers which is fed by this drainage fallout. Many wildlife species are in danger of becoming extinct due to their short life cycle.

Types of Pervious Pavement

Pervious/Permeable Pavers: This material can be used to create a porous surface with the aesthetic appeal of brick, stone, or other interlocking paving materials. They are most often used for driveways, entryways, walkways, or terraces to achieve a more traditional, formal appearance.

Permeable pavers are an environmentally friendly and attractive alternative to traditional paving methods. Unlike standard concrete, asphalt or even paver installations, permeable paver installations provide for drainage and filtration of water into underlying soils or water storage system. Permeable pavers allow water to percolate through joints or holes in the paver itself but also provide a solid surface that can withstand weight loads that are comparable to those of standard concrete or asphalt surfaces.

Permeable pavers come in many designs, and may be made from concrete, plastic or even combinations with recycled rubber. These pavers can be used for in many commercial and any residential paving application including patios, walkways, driveways, and parking lots.

Potential LEED credits for Permeable Pavers

Porous Asphalt: A great advantage to porous asphalt is that the same mixing and application equipment is used as for impervious asphalt. Only the formula for the paving material changes with porous bituminous pavement. For more details on the various layers of materials see, the Pennsylvania Stormwater Management Manual Porous pavement specification used by the City of Seattle Washington Park Department. The amount of asphalt binder required is about 6% by weight which is somewhat higher than required for standard impermeable asphalt mixes.

Bituminous permeable paving is appropriate for pedestrian-only areas and for very low-volume, low-speed areas such as overflow parking areas, residential driveways, alleys, and parking stalls. Permeable paving is an excellent technique for dense urban areas because it does not require any additional land. With proper design, cold climates are not a major limitation.

Porous Concrete: Again, the same equipment may be used as for standard concrete. Larger pea gravel and a lower water-to-cement ratio is used to achieve a pebbled, open surface that is roller compacted. This material was recently used in a parking area in Fair oaks, California as a way to reduce solar heat-gain solar from absorption. Project costs were reduced because no retention pond or connection to the municipal storm drain system was required.

Plastic or Concrete Grid Systems: High strength plastic or concrete grids (often made from recycled materials) filled with soil and planted with turf grass or a low-maintenance groundcover. Water passes through the turf block into a reservoir base of crushed aggregate, then infiltrates into the subgrade. Some are designed to be filled with gravel on top of an engineered aggregate material as well.

The grids provide a support structure for heavy vehicles, and prevent erosion. After heavy rains, the grids act as mini holding-ponds, and allow water to gradually absorb into the soil below.

Loose aggregate such as uniformly sized crushed stone can provide porous paving, although it is only suitable in light-traffic applications where it won’t quickly be displaced, ground down, or mixed with organic matter. Soft materials such as chipped bark or crushed seashells may be used as porous paving in pathways. Conventional dirt roads use mixed aggregate, including fines, and are largely impermeable.

Information found at the NAHB Research Center

Wednesday, September 30, 2009

Green Roofs

Green roofs, otherwise known as living roofs or eco-roofs, are environmentally-sensitive roofing systems that allow plants to grow on the surface of what would otherwise be just a protective covering for houses and commercial buildings. Green roofs help protect conventional roof waterproofing systems while adding a wide range of ecological and aesthetic benefits and are a powerful tool in combating the adverse impacts of land development and the loss of open space.

Just recently, VDC had the opportunity to help install a green roof locally on a residence in Leceister, NC collaborating with a local green roof company here in Asheville, Living Roofs, Inc. Working alongside owner Emilio Ancaya, VDC helped with the installation of pervious pavers and the plant material for the green roof.

So WHY build a green roof?

There are several great reasons to go green on a roof, many of which not only benefits the environment and has heating and cooling cost savings, but can also help a project qualify for LEED credits.

Reduces the volume of storm water runoff

Green roofs are known to retain 50-60 percent of the total annual runoff volume of a roof. Most importantly, the soil retains 90-100% of the critical first hour of heavy rainfall that can overwhelm storm water management systems.

Improve the quality of runoff water

Acting as natural bio-filtration devices, green roofs help reduce water contamination and help trap and filter pollutants from entering our storm water, thereby allowing cleaner water to enter our water basins.

Reduce the effects of ‘urban heat Island effect’

Covering dark conventional roofs with green roofs can significantly reduce the temperature above the roof and in the heat of the summer, the temperature on green roofs can be significantly cooler than conventional roofing anywhere from 20 to 60 degrees cooler.

Control building temperature

For hundreds of years, living roofs were used in various countries to prevent heat from escaping or penetrating during different seasons. Controlling a building’s interior is possible by replacing the asphalt surface of the roof with plants and soil, which act as insulators to keep buildings cooler in summer and warmer in winter.

Provide soothing and calming spaces to look down upon

With improvements being made in every aspect of green roof technology, we should see more green roofs offering a greater diversity of plants as well as more human access. Either way green roofs are more aesthetically pleasing, giving the viewer a soothing vista to gaze upon.

Create wildlife corridors for migrating species

Green roofs can be used to create wildlife habitats to supplement or replace diminishing open space in developing areas. Many migrating species pass through urban centers and green roofs can offer these creatures the food, shelter, and respite they need to successfully finish their journey.

The costs of going green

Long-term financial benefits

Green roofs will lower the cost of storm water management in urban areas. Once a green roof is in full operation, it should cut down on the amount of heating and air conditioning a building needs to maintain comfortable temperatures. These reductions should be seen in the monthly costs of electricity and natural gas.

Other Economic Benefits of green roof

  • Potential to reduce the size of HVAC equipment on new or retrofitted buildings (capital and operational savings).
  • Potential to reduce the amount of standard insulation used.
  • Potential to incorporate cooling and/or water treatment functions.
  • Potential to reduce or eliminate roof drains.
  • Potential to meet regulatory requirements for stormwater management.
  • Provision of amenity space for day care, meetings, and recreation;
  • Aesthetic appeal, increasing the value of the property and the marketability of the building as a whole, particularly for accessible green roofs. For example, American and British studies show that “good tree cover” adds between 6 to 15 per cent to the value of a home. Green roofs offer the same visual and environmental benefits.

Savings for the Homeowner

The average green roof lasts for an average of 40 years as opposed to the 17-year life expectancy of roofs installed with standard roofing materials, like cedar shake. Living roofs come with lower maintenance, repair and replacement expenditures than “dead” roofs. A reduction should also be noted in waste water charges.

What makes up a green roof?

A green roof system is an extension of the existing roof which involves a high quality water proofing and root repellant system, a drainage system, filter cloth, a lightweight growing medium and plants.

A green roof starts with a waterproofing layer. For existing roofs, the existing waterproofing (asphalt shingles, tar and gravel, etc.) can be used. For new construction, a single-ply membrane such as EPDM (ethylene propylene diene monomer – a rubber typically used for pond liners) or TPO (thermoplastic polyolefin – an environmentally friendly and recyclable roofing product mostly used in large-scale commercial buildings, like the Rogers Centre) is usually used. EPDM and TPO are quick to install, and also act as a root repellent, preventing plant roots from compromising the waterproofing.

On top of the waterproofing layer is a drainage, water retention and filter layers. These layers also act as root barriers. More importantly, they help manage the amount of water that is retained on the roof and ensure that the growing medium doesn’t clog the drainage layer and wash away.

The next layer is the growing medium. This is usually a lightweight, custom mixture, composed mostly of expanded stone, volcanic rock, perlite, with only a 10% to 20% organic content. The goal is to find a balance between a soil that will sustain the plants, but that won’t weigh so much as to require excessive support from the building structure.

Finally are the plants. These are chosen to match the composition and depth of the growing medium. For shallow, lightweight roofs, a mixture of sedum and delosperma varieties are typical. These shallow-rooting succulent plants do well in dry conditions (requiring less maintenance) and in “poor” soil. With deeper roofs, the plant selection can expand to include native grasses, wildflowers … even some herbs and vegetables.

Thursday, August 27, 2009

No Flushing Required

Water and energy… arguably two of the most important topics in our current dialogue on sustainability; so when technologies are developed that significantly address the conservation of both of these, we feel it is appropriate to look a little deeper. This post reviews a concept that could conserve an estimated 5 billion gallons of water per day in the U.S. alone. This could potentially save U.S. water-users nearly $4 billion annually not to mention other significant savings in energy and maintenance costs. In addition, this technology would create a nutrient-rich compost that could be used to enhance garden performance and productivity. What is this technology? …

Behold, the composting toilet.
(photo taken at Warren Wilson College Eco-dorm near Asheville, NC)

Although this technology is not new (self contained “earth commodes” have been around since the 1800’s - see below) there have been great advances in the past decade. Today, many composting toilet fixtures look strikingly similar to ‘designer-label’ conventional fixtures and are very simple to use and maintain. There are many manufacturers of composting toilets, here is a link to a good site for comparisons between various manufacturers and models. http://www.comparethebrands.com/compare/134

mid 19th Century composting toilets

Today's composting toilet - not bad eh?

Composting toilet systems have four basic components: the seat fixture, the chute, the composting chamber and the ventilation system.

image from http://static.howstuffworks.com/gif/composting-toilet-diagram.gif

The principle is simple. Human waste falls down the chute into the composting chamber. Usually a scoop of composting powder or sawdust is added to the chamber after each use.

Some systems actually utilize a microflush system that uses less than a liter of water per flush. In microflush systems there is usually either a small heating system to facilitate drying or a small leachate drain that takes excess water to a drain field or engineered wetland. There are also vacuum systems that allow for the waste to be delivered to a chamber located on the same level or even above the fixture.

In the composting chamber, microorganisms gradually break down the waste into compost. After a certain timeframe, aged compost is removed and can be used as fertilizer, the composting process having broken down harmful substances in the waste.

The ventilation system usually uses a small electric (often solar powered) fan that creates a mild vacuum in the chamber and ensures that any offensive odor is vented to the outdoors. In my research, most composting toilet users are very surprised to find they have no odor issues.

There are a few potential drawbacks to composting systems:

Additional composting materials: There will be the additional expense of purchasing and replenishing a supply of sawdust or composting powder as a scoop is placed in the composting chamber after every use.

Additional maintenance: Composting systems do require some minimal periodic maintenance to rotate and/or remove compost. Although some of the products have mechanical systems that automatically ‘stir’ the compost, many systems require someone to manually pull some sort of lever to stir the compost. Depending on the system type/size and frequency of use, the composed needs to be removed anywhere from every two weeks to every two years or longer.

Biodregadable items only: Care must be taken not to place trash or other objects in the chamber that will not quickly break down. Cleaners and other chemicals must not be ‘flushed’ as they potentially harm the friendly composting microorganisms and could contaminate the compost. Also no cigarettes or open flames (for obvious reasons).

Permitting and approvals: Many municipalities are not familiar with this technology and it may not be part of accepted standards. Thus, there is often an extended review process involved. One should definitely meet with the appropriate governmental agency well before installing a composting system.

Expense: Cost varies widely in composting systems but quality systems can be purchased for around $1,500, comparable to the cost of installing a conventional septic system. The paybacks are more immediate if these systems are employed in new construction. In more urban applications, where septic systems are not utilized, composting systems will likely have a 5 to 10-year payback period, depending on the water and sewer rates charged by municipalities. For a family the size of ours (5) here in Asheville, we would expect to see a savings of at least $200 per year on our water/sewer bill if we used composting toilets instead of conventional reduced flow (1.6 gallons per flush) fixtures, and over $400 in annual savings over conventional, full-flow fixtures. Overall, my guess is that composting toilet systems are ultimately much more cost effective than this...

In Asheville, water treatment systems and associated water department activities account for over 40% of the city's municipal electricity use and takes up nearly 1/3 of the municipal carbon footprint. This magnitude of resource consumption is similar for other cities and towns across the nation. Composting human waste offers tremendous potential savings when you consider that about 1/3 of the water that is used in residential homes is flushed down the toilet.

All in all, the small inconveniences incurred in using composting systems would appear to pale with respect to the amount of water and energy that these systems could potentially conserve. Here are a couple of other sites that contain additional information on composting toilets:



Monday, May 25, 2009

Water Harvesting

What is rain water harvesting?

Water harvesting has been around for centuries and can be traced back through human history almost as far as the origins of agriculture.  Basically, rain water harvesting is the capturing and storing of rainfall to irrigate plants or to supply people and animals. Water harvesting involves a variety of methods used to get as much water as possible out of each rainfall. The great thing about water harvesting is that it will help you save money on your monthly water bills and reduce your dependence on municipally-supplied water as well as relieve stress on the environment and recharge groundwater tables. 

Planning Your Water Harvesting System

To put it simply, all you need for a water harvesting system is rain, and a place to put it. Your system can be simple, using contoured areas so that water flows directly to planted areas, or more sophisticated, using storage systems that can contain captured water for later use.  © 2009 Rainwater Solutions - "Continuous Guttering"

Types of Water Storage

You can store water in a variety of ways: steel drums, oak barrels or underground storage tanks, to name a few. One of the simplest forms of water harvesting is to place a drum or barrel on a raised platform under a rain gutter downspout. 

Rain Barrel

Usually a rain barrel is composed of a 50 to 55 gallon drum, a vinyl hose, PVC couplings, and a screen grate to keep debris and insects out. I have a very simple rain barrel at my house that captures water runoff from one-half of my home's roof and which I use to irrigate my garden throughout the summer months.

The rain barrel should have an external pipe with a shutoff valve to control the amount of water withdrawn. What I also did for my system is raise the rain barrel off of the ground to allow for greater head pressure. If this is not possible to do, a pump may be required to get the proper amount of pressure for your use, particularly if the water will be used as part of an irrigation system.  

Another important element is the overflow for excess water.  On my rain barrel system I have put a 6 foot garden hose that distributes the overflow water into a mini-rain garden that helps to contain and slowly disperse the water over-time, into the landscape.  It is important to keep the overflow water from spilling on the ground near the foundation of a home

System Maintenance

Regular maintenance is critical to any dependable water harvesting system. Make sure your gutters and downspouts are free of debris. Periodically clean and/or repair dikes, berms and channels to prevent excessive erosion.



Cisterns are another method of water harvesting and can be constructed of nearly any impervious, water retaining material.  They are distinguishable from rain barrels only by their larger sizes and different shapes. They can be located either above or below ground, and in out of the way places that can easily be incorporated into a site design.  Commercially available systems are typically constructed of high density plastics.  Cisterns can either be constructed on-site or pre-manufactured and then placed on-site.  

A simple method of construction, sometimes still utilized in rural areas, is to first lay a concrete floor in a small excavated area and then cover the dirt walls with several coats of plaster to assure water proofing.  If the cistern is dug correctly its round walls can then be capped with a concrete lid.  Small cisterns of up to 5000 gallon capacity have been constructed in this manner.

Materials utilized for the construction of cisterns can include redwood, polyethylene, fiberglass, metal, concrete, plaster (on walls), ferro-cement and impervious rock such as slate and granite.  Typical components of a cistern roof top catchment system include: the roof, gutters, and downspouts with connection to top of cistern, and outflow connections for appropriate uses, i.e., irrigation. 

Generally all rainwater tank/cistern designs should include these components: 

  • A solid secure cover
  • A leaf / mosquito screen at cistern entrance
  • A coarse inlet filter with clean-out valve
  • An overflow pipe
  • A manhole, sump, and drain to facilitate cleaning
  • An extraction system that does not contaminate the water (e.g. a tap or pump)


What are the advantages of rain water harvesting?
Lawn and garden watering make up nearly 40% of total household water use during the summer. A rain barrel collects water and stores it for when you need to water plants or wash car. Rain barrels provide an ample supply of free "soft water" containing no chlorine, lime or calcium making it ideal for gardens, flower or the potted plants. Also, according to the US Environmental Protection Agency, a rain barrel can potentially save most homeowners about 1,300 gallons of water during the peak summer months.

Through our research and exploration of rain water harvesting we came across several good sources of information that we wanted to pass along:

Book:  Water Storage : Tanks, Cisterns, Aquifers, and Ponds        by Art Ludwig
Website: www.harvesth2o.com - an online rain water harvesting community with lots of great information 
A useful guide put out by the North Carolina State University Extension

Monday, April 20, 2009

Fun with Rain Gardens

above: my rain garden experiment

Just under a year from the time we moved into our home, we experienced stormwater in a way we never had before. This also presented an opportunity to learn some lessons in stormwater management that I thought may be of interest.

Let me explain. Runoff from the adjacent street collects in a drainage structure which used to discharge into a small pipe that ran along the northern boundary of our lot into a stream off property.

It was certainly no great feat of engineering but at the time seemed to serve it’s purpose (seemed being the key word). I’m sure whoever designed and installed the system had a basic understanding of the workings of stormwater - something like: water runs down road to low point. Put drain inlet at aforementioned low point. Attach pipe to drain inlet. Run pipe downhill and in a straight line (shortest distance right?). Point outlet to stream and we’re done. This equation works great until additional ingredients work their way into the formula. Leaves + twigs + dirt + plastic grocery sacks + discarded hamburger wrapper + tropical storm = lots of water not where it is supposed to be. We leaned this when Hurricane Ivan paid a visit in Sept of 2004.

Basically there was substantial clogging of our stormwater pipes which caused the system to literally break apart, spewing a geyser of muddy stormwater which severely eroded our yard and then puddled in our basement.

I tried several times to repair the system, but time and again, nature did not comply. I decided to try a different method of stormwater management, which takes some cues from Mother Nature herself.

I began by abandoning the underground pipe in favor of a surface system. The new system would be composed of a series of small rain gardens, terraced down the slope. The contractor who installed the previous system had buried the pipe in a trench with coarse road-base stones ranging in size from a baked potato (hey, I’m from Idaho) to small watermelons. I reused these stone to line my rain garden and armor the stream channel connecting the gardens.

I also placed several drop structures in the system. This helps to dissipate the force of the velocity during heavy runoff – it also creates a great ‘babbling brook’ resonance during rain storms.

above: cascading drop structures in the "Fern Garden"

I have found that the stormwater entering my gardens carry a surprising amount of sediment. The first pond of the system is the deepest (about 10” -12”) and has a wide, rock-lined overspill. This creates a relatively calm pool in rain events and most of the sand, trash and large sediment will drop out very beginning. I clean this out a couple of times a year and use the sediment to fill holes or spread elsewhere in the yard.

above left: street runoff entering upper pool
above right: sand and other sediment deposited in pool

I spent the most amount of time building the channel through the fern garden on the north yard of the house. This channel is stone-lined with several small waterfalls. I also laid a path by recycling broken concrete pieces from demolition (more on that in another post).

above: upper and lower pools in the fern garden

The final pool is the largest and I have found that it does a decent job at settling out clay fines and other small particles. I have started cultivating an iris garden on the margins of the lower ponds. All of the irises (Blue Flag Iris or Iris versicolor for horticulture geeks) are from a single plant (all my project budget would allow) that I’ve been dividing over the past three seasons– they do extremely well in these heavy, moist soils. I created a shelf lined with stone to protect the iris from swifter currents that develop in very heavy rain events. I plan to experiment with introducing some rushes and other plants later this season.

above: iris garden

Other plants in this garden include wild strawberry (provides quick cover), many species of native fern, rhododendron, buttercup (vigorous but also invasive – be careful), violets, a flowering dogwood, and black berry and raspberry canes. There are also some trillium and crocus for early spring interest, as well as several varieties of tulip. Most of these plants were transplanted from elsewhere on my lot, given me by friends, rescued from development sites, or are uninvited guests that haven’t been caught yet.

I have had the rain gardens in for over three years now and have really enjoyed this experiment. They have held up well and provide a lot of interest especially when it rains. I haven’t had water in my basement since the gardens went in. They also prevent several cubic feet of sediment and trash from entering our river systems.

Feel free to contact me if you have any comments or would like to know more.