Help Trees Thrive: Tear Up Some Turf

By Elaine Kolish, Fairfax County Tree Commission, photo: Plant NOVA Trees

It’s fairly common in residential neighborhoods to see trees surrounded by grass or by small mulch beds, often heaped high like a volcano. But did you know that your trees would be healthier and grow faster if you replaced that turf and mulch volcanos with a 2-4” deep ring of mulch that extends out to the tree’s drip line or even beyond? Let’s look at why this is.

Tree roots are not as deep underground as you might think. Instead they are generally fairly shallow, in the upper six inches of the soil, which is where turf grass roots grow. This means trees and turf are competing for the same water and nutrients in the soil. The grass generally wins. And of course, as trees become more established, the shade they cast doesn’t do the turf any favor. Turf grass does best with lots of sunlight, and dense shade will significantly affect grass growth and quality. Another factor to consider is that exposed tree roots in your lawn can be a trip hazard. In addition, when you mow over the grass-surrounded roots, you could be damaging them and detrimentally compacting the soil.

If you wonder how much difference turf under trees can make, one study reported that trees in turf grow at half the rate of trees that are not dealing with that competition. So if you want vigorous tree growth, no turf or less turf under them is best.

Another wonderful benefit from eliminating or reducing turf is the improvement in the survival rate of the caterpillars that turn into butterflies and moths that in turn bring beauty into our lives and environmental benefits. According to Doug Tallamy, a famous professor of entomology and wildlife ecology, a hard-packed lawn underneath a tree does not provide adequate pupation sites for caterpillars that may have been feeding on your native tree, such as an oak. The caterpillar may find no leaf litter (because the lawn has been cleaned up) in which to spin a cocoon, or if it is a species that burrows into the soil, it won’t find any loose soil if there is only turf under the tree. And we need these insects, not just for their beauty, but for their role as pollinators and as food for other wildlife. As E.O. Wilson, the eminent ecologist, famously said, insects are ”the little things that run the world.”

So consider eliminating the turf under your trees or combining various smaller mulched areas into a bigger area. Your trees will be happier (and you will have less lawn to mow and maintain)! But, remember, don’t let the mulch touch the trees—stay one to two inches away from the trunk to avoid bark rot. Too deep a mulch layer will keep water from reaching the soil – two to four inches is ideal. Best of all is to use arborist wood chips (which you can get for free from Chip Drop or from any tree company that needs to dispose of the chips after felling a tree), as they don’t mat down the way standard bagged mulch may.

Once you have wider rings around the trees, you will have the opportunity to create more biodiversity and habitat by under-planting with native plants including shrubs, flowers and ground covers that thrive in shade or part shade (think ferns and wild ginger). Native plants have different root depths compared to turf grass, so you won’t have the same unhealthy competition for water and nutrients that you did with turf. You can find details about these plants on the Plant NOVA Natives website.

Pushing back the turf is a project you can do before the ground freezes, or you can start planning your beds now, while other garden tasks are on hold, for spring installation.

MVHS Science Fair – Judges Wanted

Our friends at Mount Vernon HS are asking for volunteers to judge their science fair.

E152: Science Fair Judge at Fairfax County Science Fairs — FCPS

Several FMN have supported them in past so their request was sent to previous judges but it is not limited to previous judges. Read on…

“Good morning,

My name is Anna Gosling. Cory Smith and I are the Science Fair Directors at Mount Vernon High School. First, I would like to thank you for volunteering as a judge at one of our previous Science Fairs. Our students and teachers greatly appreciate your time and knowledge—I know I have been impressed by how much my students have grown from your feedback. Mount Vernon would be extremely grateful if you were able to volunteer again as a Science Fair Judge.

This year’s Science Fair will be held on Monday, January 29 (snow date: February 2) from 8:00 am to roughly 12:00 pm for general judging, or as late as 1:00 pm for Grand Prize judging.

If you would be interested in volunteering your time as a judge again, please complete this Google Form let me know if there is a particular category that you would like to judge.

Thank you in advance for your time.”

If the form does not work in your reader, here is Anna’s contact information:

Anna Gosling
[email protected]

AHS Blue Bird Trail – Building Team FMN

Washington’s River Farm, the headquarters of the American Horticulture Society (AHS) is renovating their Bluebird Trail and FMN is building a team to help.
The Eastern Bluebird, Sialia sialis, once as common as the robin, saw a drastic decline in population for many reasons including loss of habitat, pesticide use, snag removal, an influx of house cats and the introduction of the House Sparrow and the European Starling. The American Bluebird Society (ABS), started a conservation movement in 1978 to put up boxes and monitor the numbers and health of the bluebird population. Their successful program continues today.

One of several sad looking boxes to be replaced – photo Jerry Nissley

Fairfax Master Naturalists is putting together an ABS team to help install the bluebird boxes at River Farm and monitor the boxes between March and July. Training will be provided. If you are interested in any aspect of this project, please contact FMN Susan Farmer [email protected] with your availability and level of interest.  Volunteer for installation, or installation and monitoring, or monitoring only – whatever works for you. The Blue Bird boxes have arrived and will be installed on 13 Jan 2024. If you can help, please contact Susan Farmer.

AHS is a new FMN chapter partner located along the Potomac River. FMN has approved stewardship, educational, and citizen science project codes for this blue bird opportunity and many other volunteer opportunities to support AHS River Farm. S275, E275, and C275, respectively.

Bird Friendly® Certified Coffee (and how you can help) Webinar, January 18th

Photo: Courtesy of the Smithsonian Bird Friendly certification

Thursday, January 18, 2024
7 – 8 pm
Free but registration required.

Did you know that the coffee you drink can affect the birds in your backyard? The Smithsonian Bird Friendly certification does more than any other certification program to conserve habitat for birds and other wildlife on coffee farms. Bird Friendly Program Manager Kirstin Hill will describe the link between coffee and conservation, discuss what makes Bird Friendly certification the gold standard in biodiversity protection, and share ways to get involved in the movement to “Drink Bird Friendly.” Your coffee is stronger than you think! Currently, we know of no coffee shops in northern Virginia where you can buy a fresh hot cup of bird-friendly coffee – and we want to change that! We are looking for volunteers who are inspired by this program to help us with coffee shop outreach.

Climate Extremes: What’s the Forecast for Invasive Species?, Webinar, January 16th

Photo: Julia Blum

Tuesday, January 16, 2024
7 pm
Register here.

As the planet heats up, non-native species all over the U.S. are pushing north to follow the warmer weather. But the simple narrative doesn’t end there. Dr. Andy Chang, lead marine biologist for Smithsonian Environmental Research Center’s California branch, has tracked the movement of species introduced by human activity to San Francisco Bay and the California coast for the past two decades. In addition to northward and upstream migrations in warmer years, his team has also noticed species getting wiped out in years of intense rainfall. In this talk, he’ll reveal how climate change and extreme weather like droughts and floods are changing the seascape for invaders. He’ll also highlight how countries can use this knowledge to help stop nascent invasions before they get a foothold, in San Francisco Bay, Chesapeake Bay and around the world.

Elly Doyle Park Service Awards 2023 – Early Detection Rapid Response Team

FMN Betty Hoblitzell has been a Fairfax Master Naturalist since 2013 but her dedication to habitat restoration and a long-term commitment to Fairfax County Park system goes back longer. She has worked with the Rapid Response Team for 13 years, attending some of the first organizational meetings in 2010.

According to the National Park Service the Early Detection and Rapid Response (EDRR) program finds new populations of certain invasive species through methodical surveys as they are starting to invade an area and then eradicates them before they cause serious ecological harm in county parks. The concept EDRR is fundamental to effective invasive species management. The program adds information to Early Detection and Distribution Mapping System (EDDMapS) that tracks invasive species across the country.

Invasive plant species are known for their stealth, quietly invading neighborhood parks, a meadow or woodlands area, overwhelming native plants and before you know it, taking the place over. To combat this aggressive behavior, the Early Detection Rapid Response Team was developed and is ready to go on short notice, leading surveys for the Park Authority’s Invasive Management Area program and determining the appropriate actions.

At the core of this innovative approach are three volunteers including FMN Betty Hoblitzell who have demonstrated their ability, knowledge of the environment and amazing dedication to the Park Authority.  They spend many hours engaged plant specific surveillance throughout the 24,000-acre park system. Post survey, they report on invasive density, removal efforts, volunteer or contractor treatment options and create a rough map of the infested area.

In the past year, these three committed volunteers have given more than 225 hours to Rapid Response teamwork, covering more than 200 acres in a matter of months. Their work has curbed wavyleaf basket grass incursions, as well as multiflora rose, stopping the spread early to conserve time, money, and other resource management tools.


Earn a Lifetime Pass to Virginia State Parks by Volunteering

Article compiled by Jamie Leeuwrik, Chief Ranger – Visitor Experience, Mason Neck State Park, FMN Chapter Co-Advisor

Although Lifetime Passes may no longer be purchased to Virginia State Parks, they may be earned through logging volunteer hours. Here is a list of the benefits you may earn by logging hours.

Those interested in volunteering at a State Park may reach out to the park itself for information, or to the volunteerism program.

To start the process of volunteering at a State Park, all volunteers must complete an application and background check. The background check is the same that all non-Law Enforcement park employees must also undergo. The application is available online only, and the background check authorization form can be submitted to the park or to headquarters.

An application may appear complete, but until a background check has been completed and the volunteer officially cleared, they are not able to log into their account to log hours. Here is a copy of the form Mason Neck State Park uses as an example.

Once the volunteer account is complete, volunteers may begin logging hours. Here’s more information.

All the information from above and more is available here.

Volunteers may choose more than one park as a park they are interested in volunteering at. Once a volunteer profile has been completed, it is active for all State Parks, but a “primary” park must be selected and will be the default when logging hours, but can be changed.

Grasses for the Masses – PSA

The FMN stewardship code for Grasses for the Masses has been inactivated.
Habitat Creation and Restoration – S015: Grasses for the Masses — Chesapeake Bay Foundation.
This project is no longer sponsored by CBF and the code has been inactivated. However, DCR (Virginia State Parks) is a sponsoring organization for this program and Mason Neck is our State Park within Fairfax County where people can participate in this program.

Check out this Mason Neck link for program details:

If you would like to participate in the Grasses for the Masses project, FMN hours should now be charged to Parks – S179: Stewardship Projects for State Parks. Instructions on how to participate are found in the above link. Orientation sessions begin in January 2024.

Come to the Mason Neck State Park for Guided First Day Hikes, January 1st


Monday, January 1, 2024

Mason Neck State Park
7301 High Point Rd, Lorton, VA 22079


Join Park Staff on a guided hike this January 1. First Day Hikes are the perfect way to start the year! Each trail is unique, and the leaders will offer information about the park and its plants and animals along the way. The Visitor Center will be open for more hands on activities, and to warm up if needed!

9:30 am: Kane’s Creek to Eagle Spur trail. Roughly a 3.8 mile hike. Packed dirt trail with stairs and roots. Not wheelchair or stroller friendly.

11:30 am: Tundra Swan Hike at the Woodmarsh Trail at Elizabeth Hartwell Refuge.  Approximately 2.5 miles loop. Not wheelchair friendly, Limited space available for this hike only. Recommended for ages 8 and up. Registration is required. Register at

12:00 pm:Dogue Trail hike and roll. Wheelchair accessible. Approximately 0.85 miles, packed gravel trail.

3:00 pm: Family-friendly hike on Bay View Trail. Approximately 1.25 miles, with stops and hands on opportunities for adventure and exploration. Packed dirt surface trail with boardwalks and exposed roots.

The Friends will provide hot coffee and cocoa from 9:00 to 11:30 AM.

Admission and parking are free on January 1. 

Solar panels vs. trees – how to choose?

Article and photo by Plant NOVA Natives

Residents who are interested in installing solar panels often face a dilemma. Which is better for the environment, solar panels or shade trees? After all, climate change due to burning fossil fuels is threatening the very existence of trees, not to mention human beings, and the timeline for preventing catastrophic temperature rises is short. Before we get out the chainsaw, though, there are several other things to consider.

One of the main reasons to try to limit temperature rises is to prevent ecosystem collapse. The native trees in our yards are as much a part of that ecosystem as the ones in the Amazon, providing food, shelter and nesting places not only for birds and mammals but for a myriad of invertebrates that are a critical part of the web of life. If we do not even protect the environment where we live, we can hardly expect people in the Amazon to take more of an interest.

Sunny rooftops are an ideal place to put solar panels, since that real estate is already built upon, and since decentralizing the grid helps build resilience. The land use anticipated for solar farms and new transmission lines is so massive, and the willingness of companies to replace forests with them so counterproductive and disheartening, that the more we use our own rooftops, the better. But solar energy is neither the only way to reduce fossil fuel use nor the most efficient of the various options for homeowners. The first step should always be to reduce energy consumption, by weatherizing and taking other steps to reduce waste. For those ready to make a big investment, an alternative to consider is a heat pump or even a geothermal system for heating and air conditioning. As is true for solar panels, the cost of installation can be partially offset by a significant tax credit. Some utility companies including Dominion allow customers to choose a renewable energy option (although “renewable” is not always the same as “clean,” since it includes burning chopped down trees, for example. But much of that electricity is generated by wind and solar farms.) It will take considerable effort and broad participation for our community to meet its climate goals, but not everyone has to do everything themselves on their own property. Those with sunny roofs can contribute solar energy. Those with trees can take care of them.

Trees themselves are what are known as a “natural climate solution.” They provide benefits that mitigate the effect of climate change. Trees improve the energy efficiency of houses. In the winter, they reduce heating costs by blocking the wind. In the summer, they reduce air conditioning costs, since roofs and walls in the shade are often twenty degrees cooler than those in the sun. In addition, trees improve air quality and sequester carbon dioxide. Their ability to capture stormwater is particularly important in flood-prone suburban and urban areas with their excess of impervious surfaces. The leaves of the trees capture much of the rain before it even reaches the ground. Once it does, transpiration by canopy trees sucks thousands of gallons of water from the ground, thus enabling the soil to control flooding.

It is interesting to use the National Tree Benefit Calculator at the bottom of this web page to see what you save in monetary terms by preserving a few mature trees, strategically located around your property. For the birds and other critters that depend on them, the native trees are priceless.