District of Columbia Invasives Day, Sept. 8th

Saturday, September 8th, 2012

The DC Cooperative Weed Management Area

Cordially invites you to

Participate in DC INVASIVES DAY, which is aimed at increasing awareness and community efforts toward managing invasive plants and promoting native wildlife habitat in Washington, DC.

The DC-CWMA members, partners and others will host various sites around the District where residents can engage in invasive plant removal as well as learn about invasive identification and restoration. It’s a great opportunity to connect with the managers some of these parks to learn more about wildlife management efforts and take part in restoring areas to promote wildlife conservation. There are several sites throughout the city and we are still looking for more sites, leaders, community groups and residents to engage.

Sites (Include):

Rock Creek Park,  Dumbarton Oaks Park , Kenilworth Aquatic Gardens, Fort Dupont Park, C&O Canal Park,  Kingman Island,  National Arboretum

For more information and to RSVP contact: Laura.Washington@dc.gov

For more information on the DC Cooperative Weed Management Area - please click this link DC-CWMA. They are still looking for additional sites, community partners and residents to engage, please contact Laura if you would like to lead a group, suggest a site or learn more about the event.

Avoiding the invasives

I read a great article about the native/invasive plant debate online recently entitled Foreign Invasion: Is Your Garden A Danger?  It’s a common topic among green gardeners who are often tempted to add a plant to their garden because of its aesthetic qualities without really giving much thought to what its going to do to their landscape…. or the surrounding landscapes….in the future.

Although there are many plant species out there that can tempt us to invite them home for a visit, some of them can become very pushy and invasive, and getting rid of them can be as difficult as eradicating a visiting houseguest who is already starting to rearrange the furniture in your guest room.

While you may not be too concerned because the problem seems contained to your backyard, Emily DeBolt, who is quoted in the article, says that  80 percent of the plants used in gardens have exceeded their boundaries and taken over roadsides, wetlands and fields.

“With more development, more habitat loss, our gardens are part of the bigger environment, the bigger ecosystems. What we put in our gardens does matter; it’s not just our own space,” DeBolt said.

The article reminds us that invasive plants can be spread in many ways. Birds and other forms of wildlife can eat berries and spread them through the neighborhood through their droppings. And, of course, seeds can be carried by wind, water and humans or animal fur.

And once they take hold, the effects of the non-native plants can adversely affect the environment, economy and human health.

The better alternative, of course, is to choose native plants which are suited for your own site conditions. Native plants generally require less harmful chemicals and supplemental water, which helps to save you money and help protect the environment.

Natives help protect waterways, too, because the deep roots absorb stormwater run-off better than turf grasses and the shallow root systems of ornamental plants.

The article suggests that a few extra precautions should be  taken if you do decide to remove some of your invasive plant species.

…if you’ve decided you do want a more eco-friendly garden and wish to rid your garden of the offending plants, pull them out and place them in a black garbage bag. Let it sit in the hot sun until the plant material turns to mush, and dispose of it in the trash. Don’t put the plants out for waste pick up or in a compost pile, and check with your local department of public works for more disposal information.

To Read the full article: Foreign invasion: Is your garden a danger?

10 Ways to Observe National Invasive Species Awareness Week

February 26 - March 3, 2012
Washington, DC

A week of activities, briefings, workshops and events focused on strategizing solutions to address invasive species prevention, detection, monitoring, control, and management issues at local, state, tribal, regional, national and international scales.
Full Description:
National Invasive Species Awareness Week (NISAW) includes activities, briefings, workshops, and events focused on strategizing solutions to address invasive species prevention, detection, monitoring, control, and management issues at local, state, tribal, regional, national and international scales. Visit the NISAW website for complete information and to register. Participants may attend some or all of the events. The total cost to participate is $85.

If you can’t attend the events, here are TEN WAYS TO OBSERVE NATIONAL INVASIVE SPECIES AWARENESS WEEK (from the the February 26 – March 3, 2012
1. Do Some Research:  Get on the Internet and find out what’s invasive in your area, region or state. Identify which species might be growing in your backyard or neighborhood.  Visit http://www.invasivespeciesinfo.gov/unitedstates/main.shtml to get started.
2. Join in an Eradication Effort: Many parks and nature reserves manually remove invasive plants (and sometimes animals) with the help of local volunteers. These outings are a great way to get some exercise, enjoy time outdoors, meet new friends, and gain the satisfaction of knowing that you're helping to protect your natural heritage.
3. Become a Citizen Scientist:  Whether you are collecting scientific data to be used by local, state, or national agencies and organizations or actually helping get rid of the invasive plants and animals, you will be able to see up close and personal the impacts of invasive species and the results of your efforts. Visit Citizen Science Central (http://www.birds.cornell.edu/citsci/) to learn more.
4. Visit a Garden, Park or Nature Center: Spend an afternoon at a botanic garden, park or natural area and familiarize yourself with the native flora and fauna in your area. See if a guided tour is offered.
5. Read a Book: Not an outdoor type?  Find a book and read up on the threats posed by invasive species.
6. Donate: If you can’t give time, you might be able to give money. Even small amounts can help local invasive species organizations with control and management and other costs.
7. Start a Garden: Replace your invasive landscape plants with native alternatives. Unlike many non-­‐native plants, native plants are hardy, less susceptible to pests and diseases and are unlikely to escape and become invasive.  They help conserve water, reduce mowing costs, provide habitat for birds, butterflies and other wildlife, protect the soil and save money on fertilizer and pesticides. (bloggers note: and save the planet in the process)
8. Legislate: Write a letter to your local state representative or get involved with an activist group. Let your lawmakers know your opinions about the impact of invasive species on our natural heritage.
9. Take the Invasive Species Challenge: One of the most effective ways to manage invasive species is for recreationalists such as boaters, fishermen, pet owners, and gardeners to not be unknowing vehicles of dispersion. Download the pdf for more info.
10. Spread Awareness: Take your National Invasive Species Awareness Week commitment beyond this week. Tell your friends, family, neighbors and others about invasive species!

Monster Plant Could be Moving this Way

An article I read online in the Pocono Record this morning had this headline:

'Monster Plant' Could be Moving this Way

Excerpts from the article, which talks about a plant that is "so nasty, it will make your skin boil --- literally", note that this plant has already become established in Maryland and Virginia.

Look, but don't touch 

"Giant hogweed exudes a clear, watery sap that causes the skin to become photosensitive to ultraviolet radiation," said Don R. Robbins, weed control administrator for the Maryland Department of Agriculture. "Contact with the sap can result in severe burns, blisters and dermatitis, possibly leading to future complications, namely skin cancer."

The Michigan Department of Agriculture states: "This tall, majestic plant is a public health hazard because of its potential to cause severe skin irritation in susceptible people. Plant sap produces painful, burning blisters within 24 to 48 hours after contact. Plant juices also can produce painless red blotches that later develop into purplish or brownish scars that may persist for several years. For an adverse reaction to occur, the skin, contaminated with plant juices, must be moist (perspiration) and then exposed to sunlight. Some other plants are capable of causing this reaction, known as phytophotodermatitis."

Giant hogweed grows in a variety of habitats such as river bottomlands, roadsides, disturbed areas, lawns and gardens.

There are two large native plants that look like hogweed — purple angelica (Angelica atropurpurea) and cow parsnip (Heracleum lanatum); and one introduced species, poison hemlock (Conium maculatum). All these grow in the same habitats as giant hogweed.

Although this plant isn't new to the area (it was listed as the Invasive Species of the Month in Maryland back in 2003 and an Exotic Invasive of the Quarter in Virginia in the Winter 2011 issue of the Virginia Forest Landowner), the article is a good reminder that we should all become familiar with the problem plants and critters that live in our area.

Natives vs aliens - the great gardening debate continues

I did a search on this blog recently to see how often I've mentioned native plants. The answer is: A LOT. That, of course, is because native plants are often mentioned as a good choice for environmentally friendly landscapes.

In many cases, the use of native plants is cause for debate, and often, heated debate. Some advocates of native plants think that gardeners should plant ALL natives. Others feel that it’s okay to plant both natives and non-natives, which are sometimes called alien or exotic species.

The debate has been a hot topic on local gardening blogs recently, in part because of a New York Times Op Ed piece entitled Mother Nature’s Melting Pot, in which writer Hugh Raffles expresses his opinion that “non-native animals and plants …provide significant benefits to their new home.”

The debate has been a hot topic on local gardening blogs recently, in part because of a New York Times Op Ed piece entitled Mother Nature’s Melting Pot, in which writer Hugh Raffles expresses his opinion that “non-native animals and plants …provide significant benefits to their new home.”

Raffles goes on to make statements such as  “many of the species we now think of as natives may not be especially well suited to being here” and “non-native plants and animals have transformed the American landscape in unmistakably positive ways.”

The NYT’s piece has been noticed and mentioned on some of my favorite local garden blogs, including Garden Rant: Uprooting the Gardening World and Grounded Design.

I've been reluctant to add my two cents worth to the debate, since I admittedly do not have any formal education on the subject. So instead of an opinion, I thought I would mention some of the key points that keep me, and others, so confused about natives.

First, what is the definition of a native plant?

Native plants are generally defined as those that occurred here without human introduction. In other words, they are the plants that were here when this continent was wild and natural. They sprung up on their own, were dispersed by wind and wildlife, and evolved and were acclimated to the characteristics of the local conditions: the climate, soils, timing of rainfall, drought, and frost; and interactions with the other species inhabiting the local community.

This definition is the basis of why native plants are assumed  good for the environment. Plants which are acclimated to local conditions would logically be more adapted to surviving local conditions and supporting local wildlife.

Now, before I go any further with the discussion of native plants, picture for a moment what this continent looked like before it was “discovered” and “civilized”. In many ways, it was a wild, almost hostile wilderness. Was it beautiful and self-sustaining? Probably. Did it need pesticides and fertilizer and irrigation systems to survive? Of course not. Was it an environment in which the “pioneers” chose to live? No. Immigrants to this country immediately began chopping and thinning and adding and taking away things from the soil and planting new things that they brought from their home countries. The definition of native plants says that they were acclimated to the conditions of the land hundreds of years ago. In my un-trained, un-scientifically educated mind, it doesn't make sense to assume that those same plants would necessarily be acclimated to current site conditions.

My husband and I live on piece of property that is very, very wooded. We only have small  garden areas. So, yes, 95% of our yard consists of the native plants that have been here for hundreds of years. As for all of the other garden areas, when our home was built, huge truck loads of dirt were trucked in to raise the foundation. So whether we leave that dirt and try to plant in it or add supplements, whatever we end up with is NOT native soil. The truth is, not very many of the factors that affected the native landscape “before human intervention” are present in modern landscapes.  The soil is different, not just because it has been moved around  from place to place but also because hundreds of years of man-made "stuff" has seeped into it and trucks and homes have compacted it. The climate is different, the drainage patterns are different.

There is a great resource on Virginia.gov entitled Native Plants for Conservation, Restoration and Landscaping. Many of the points in the document only add to my confusion.

Plants evolve over geologic time in response to physical and biotic processes characteristic of a region: the climate, soils, timing of rainfall, drought, and frost; and interactions with the other species inhabiting the local community. Thus native plants possess certain traits that make them uniquely adapted to local conditions, providing a practical and ecologically valuable alternative for landscaping, conservation and restoration projects, and as livestock forage.

If plants evolve over time in response to the characteristics of the region (which certainly have changed over the last few hundred years), why is it logical to think that only the NATIVE plants have evolved to fit the characteristics of our present-day site conditions?

In North America, plant species are generally described as native if they occurred here prior to European settlement. This distinction is made because of the large-scale changes that have occurred since the arrival of the European settlers. The Europeans imported a variety of plants to this country, many are still the major component of traditional lawns and gardens. They also include many beneficial plants important in farming, such as vegetables and grains. Today, approximately 25% of flowering plants in North America are non-natives or alien species, most of Eurasian origin.

Again, if the European settlers brought plants over here hundred of years ago, wouldn't they now be adapted to current site conditions?

I have never advocated the use of ALL native plants to anyone who doesn't make the choice on their own. First, because I think that gardens should be places of pleasure and creativity.  Gardens are where humans can work hand in hand with nature to create their own, personal work of art, and trying to direct what or how someone plants would stifle their creative process.

But the main reason that I don't "push" native plants is because I believe much more in the theory of "right plant, right place", or choosing plants to fit your CURRENT site conditions, not the conditions of what your part of the continent was like before humans set foot on it. And it makes sense to me that if I choose plants that fit the soil, water and temperature conditions for my site, then they will need less maintenance, less water, less chemicals, and, therefore, will be better for the planet, as it is today.

Again, I'm not an expert on the subject. I learned the lessons of  Right Plant, Right Place from various horticultural classes that I have taken and they have lead to my continued advice to learn to Work With Mother Nature, not against her. I believe that  getting to know your own property is key. Walk around, see where the water settles, get a soil sample, check out where the sunny and shady spots are. I'm pretty sure you will find out that none of that is the same as it was hundreds of years ago.

I certainly understand the value of using some native plants. But the benefit of using plants that
are suited to our current site conditions is that they shouldn't require extra water or fertilizer or pesticides, which will keep us from harming the current environment  even more and maybe, just maybe, will help us get the planet back to the way it was before we started "civilizing " it.

To quote one of my favorite aliens, doing anything else would seem illogical.

Resource for more information on the concept of Right Plant, Right Place:

Landscaping and Gardening – Fairfax County

Soils and Drainage - Fairfax County

Plant Right for Your Site

Waterwise Landscaping and Watering Guide (pdf)

New controversary about invasive species?

I was wondering why I was seeing so many articles about exotic and invasive species recently and then I discovered that last week was National Invasive Species Awareness Week.

The articles that I have seen floating around on local blogs and garden discussion groups seem to be slanted towards the opinion that exotic species might not be quite as bad as they were once thought.

A contributor to the WashingtonGardener Yahoo group mentioned Mark A. Davis's new book, Invasion Biology, in which he states that invasive species might actually be getting a bad rap.

Davis certainly doesn't say that ALL invasive species are okay. But he does say that if an exotic species is “not causing significant harm,” then “altering one’s perspective is certainly much less costly than any other sort of management program. ”

In my mind, Davis's highly controversial opinion does make sense. There seems to be a tendency to assume that all exotic, non-native species are bad and that all native species are better.

Much of this is, of course, a matter of semantics. Many people seem to interchange the words exotic and invasive and, of course, all exotic species are NOT invasive and some are even considered beneficial by many (did you know that many species of honeybees are non-native?)

According to the USDA National Invasive Species Information Center, an invasive species is defined as:

1) non-native (or alien) to the ecosystem under consideration and 

2) whose introduction causes or is likely to cause economic or environmental harm or harm to human health.

By this definition, the fact that a plant or animal is alien (exotic) does not, by itself, make the organism invasive.

According to another website, over 85% of exotic species are NOT invasive.

Continuing the discussion on the Yahoo group, trumpet vine was mentioned as being both Native and Invasive. Again, this is a matter of semantics.

The NC State University website states that:

Native plants are never invasive. The term invasive applies only to exotic plants and not to native plants; invasive implies a negative effect on native plants and animals. On the other hand, native plants that establish quickly in your garden and spread readily are more appropriately termed “aggressive”.

The same website goes on to provide this statement:

There are many exotic plants that do not become invasive, and many can safely be planted in your landscape. However, it takes scientists many years or even decades to fully understand an exotic plant's potential invasiveness. New information is being gathered, and you should check with your local nature center, botanical garden, or Cooperative Extension agent to find out about a plant's invasiveness before introducing it to your property. 

We can easilly heed that advice by referring to these local lists of problematic invasive species in Maryland and Virginia.

Invasive Species of Concern in Maryland

Invasive Alien Plant Species of Virginia (pdf file)

Another term to add to the discussion is the word "noxious", which I found on a National Park Service website. 

Noxious Weeds.  The term noxious is a legal designation used specifically for plant species that have been determined to be major pests of agricultural ecosystems and are subject, by law, to certain restrictions. The U.S. Department of Agriculture regulates noxious weeds. Plants can also be designated as "noxious weeds" by states and counties, usually through "noxious weed boards". Many noxious weeds are designated for their impacts to agriculture also threaten natural areas.

You can refer to this USDA page to find plants listed as Noxious Weeds in your state: State Noxious Weed Lists

Volunteers needed to help remove invasive species

Local reader Anne B. sent an email message after my post about local tree planting and asked if I knew of any plans to remove kudzu and ivy that are "choking" many of the trees in the area.

In response, here is a list of invasive weed removal activities which are planned. Volunteers are welcome to participate!  

Sunday, March 13 from 10 a.m. to 1 p.m. - Invasive Weed Removal at Scott’s Cove, 10964 Harding Road, Laurel  

Saturday, March 19 from 9 a.m. to Noon - Invasive Weed Removal at Brighton Dam, 2 Brighton Dam Road, Brookeville  

Sunday, March 20 from 9 a.m. to Noon - Invasive Weed Removal and Tree Planting at Pigtail Recreation Area, 5400 Green Bridge Road, Dayton  

Saturday, March 26 from 9 a.m. to Noon at the Patuxent next to WSSC’s Office, 14501 Sweitzer Lane, Laurel  

Sunday, April 10 from 9 a.m. to Noon - Invasive Weed Removal at Brown’s Bridge Recreation, 2220 Ednor Road, Silver Spring  

Saturday, April 16 from 9 a.m. to Noon - Invasive Weed Removal at Scott’s Cove, 10964 Harding Road, Laurel, MD 

For more information, contact Kimberly Knox - 301-206-8233 or email kKnox@wsscwater.com  

More local groups that have invasive plant removal volunteer opportunities:

• Anacostia Watershed Society
• Sierra Club, Maryland Chapter
• Fairfax County, Virginia
• Virginia Master Naruralist - Invasive Plant Removal Day (May 7, 2011)
• Maryland Native Plant Society
• DC Woodlands

I can resist everything except temptation

With the current condition of our winter gardens, it is easy to be seduced by photos of all of the colorful, exotic beauties that are gracing the pages of our seed and garden catalogs and websites. But before we pull out our credit cards and start placing our orders for spring planting, perhaps we should revisit our post from way back in July 2010 called the 12 Relationship Rules for Gardeners.

Several of the "Relationship Rules" mentioned in that post remind us of the importance of choosing plants that are appropriate to our planting zone and site conditions. Choosing plants that don't fit our site conditions is a waste of money and usually leads to disappointment. Or as I said in that previous post:

"If you want to be in a relationship with sweet things that you aren’t really compatible with just because they are beautiful, it might work but it is going to require a lot of effort. Probably neither one of you will ever be completely happy." 

The problem is, if you haven't already taken a site survey and gotten to know your landscape on a personal level, winter is not really the best time to do so. Sun, shade and water conditions are all different now then they will be a few months from now. However, this post Work With Mother Nature, Not Against Her, provides some guidelines for getting started. And you can also go ahead and learn a little bit more about your site by getting a pre-season soil test.

Are there other steps that can be taken to insure that you aren't seduced into unhappy or unhealthy gardening relationships? Sure! There are hundreds of on-line dating sites that allow people to learn a lot about their prospective partners before they ever meet them face to face. And there are just as many websites that help you to get to know your plants before you invest too much time and money in them.

Most seed and garden catalogs (and websites) provide some level of information about the needs of the species that they have for sale. The information can be as limited as just the USDA hardiness zone or it can contain uncertain terms such as "partial sun". Neither of these limited bits of information is really that useful. After all, Albuquerque, New Mexico and Washington, DC are in the same USDA hardiness zone. That doesn't mean that the same plants will necessarily thrive in both locations.

Other companies provide very detailed information about the plants, including light, moisture and soil conditions, as well as whether they attract certain forms of wildlife, such as hummingbirds or butterflies.

In any case, cold winter nights are the perfect time to do a little research about plant choices for your yard. So here are some gardening resources for learning about local plants. Think of them as dating sites for your garden - the perfect places to find your Perfect Plant Match and create more Harmony in the garden.

Recommended Plants for the Washington DC Area
Native Plant Resources for Maryland
Wildflowers Native to Maryland
Recommended Native Plant Species - select your region
National Gardening Association PlantFinder
Plant Information Online

Why are the good looking ones so naughty?

Back in July, I wrote about the 12 Relationship Rules for Gardeners. This tongue in cheek post compared the challenges of creating a healthy landscape with the challenges of building a healthy relationship.

Rule number 7 mentioned that choices based on looks alone are often more trouble than they are worth. Such is often the case when we add non-native, invasive species to our landscapes.

As defined by the U.S. Department of Agriculture: Invasive plants are introduced species that can thrive in areas beyond their natural range of dispersal. These plants are characteristically adaptable, aggressive, and have a high reproductive capacity. Their vigor combined with a lack of natural enemies often leads to outbreak populations.

As gardeners, it is sometimes tempting to want to add some of these plants to our landscape. After all, a plant that self-propagates or spreads to quickly fill in a large area can seem like a good thing. But once invasive plants take over our native plants, the result can be:

• an area's natural biodiversity is destroyed
• native plants can eventually become permanently eliminated
• the animals that need native plants for food and habitat cannot use many of the non-native ones
• it can costs billions of dollars to control invasive exotic plants

Native plants, on the other hand, generally require less water and less chemicals, which make them much friendlier for the local environment.

Once you decide to start creating a more eco-friendly garden, some of the decisions you have to make may be tough ones. But in the long run, choosing native plants, or at least NON-invasive species, will be much better for the environment and much easier to maintain.

Here are links for more information about invasive plant species in the area:

Invasive Species of Concern in Maryland

Invasive Alien Plant Species of Virginia (pdf file)

Native Alternatives to Invasive Plants (pdf file)