Posts

The Magic of Winter Trees: Making a Deeper Connection

/in , /by

Photo: Plant NOVA Natives/Plant NOVA Trees

Article by Cindy Speas, Fairfax County Tree Commission

Winter is a lovely time to get to know your trees better. Many folks spend some of the colder days of January and February planning their spring gardens, winter sowing, or putting in nursery orders for spring delivery of native plants. Dreams of warmer days are lovely, but if you have trees in your yard or a nearby park, winter might also be the time to learn how to appreciate and protect their incredible beauty.

When our trees are bare of leaves, you can visualize more clearly their beautiful shapes, identify some species characteristics and assess their health status. There are several local organizations that provide winter educational hikes or webinars to examine and learn about our forests, including Nature Forward, Virginia Native Plant Society – Potowmack Chapter, Capital Nature, Loudoun Wildlife Conservancy, Audubon Society of Northern Virginia, Prince William Conservation Alliance, and others.

If you haven’t taken a long walk or hike in the winter before, it’s time to bundle up and head out on the trail. Even if you aren’t an experienced birder, it’s often easier at this time of year to observe hawks, owls, or other raptors at work. Smaller birds can be spotted searching tree bark or leaf litter for insects and berries, and mammals often make a long-distance appearance as they look for food. Native evergreens or the lovely marcescent (persistent) leaves on oaks and beeches provide beautiful color among the gray tree trunks. While you may not want to linger for contemplation, if you walk gently, there is a type of forest bathing you can experience surrounded by the still, silent trees in the chilly air. One of the loveliest things you can see in a winter forest is found by looking up to the sky:  it is in this season that you can see how the tree canopy develops—trees grow side-by-side leaving a path around each canopy’s branches so that sunlight may reach down to the forest floor. This is called canopy shyness. While more common in rain forests, these fascinating patterns of sky and crown branching can sometimes be seen in groupings of the same tree species, and are spectacular to observe.

For those that love to undertake vigorous outdoor work in the winter, now is the time to protect our trees by starting to pull, dig, or hack and squirt the invasives in your yard or to volunteer for similar ongoing activities in your community. With the exception of a few native evergreens, almost all the large swaths of green you see in your neighborhood and along the roads are invasive, non-native plants—from Wintergreen to Vinca, to English Ivy, from Privet to non-native Holly species, to Bamboo. You can find organizations with volunteer opportunities on the Plant NOVA Trees website. Invasive plants displace the tree seedlings that are essential for our future forests, and some of them directly kill the larger trees.

So, if you want to learn about trees, to more closely observe nature, to find quiet time for spiritual reflection, or to vigorously get rid of tree enemies, winter is a magical time to spend outside in the stillness and beauty of the forest.

 

Solar panels vs. trees – how to choose?

/in , /by

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.

Fall Cleanup in Two Easy Steps

/in , /by

Article and photo by Plant NOVA Natives

Here is an executive summary of eco-friendly yard maintenance recommendations for fall.

  1. Watch the pretty leaves flutter down from above.
  2. Do as little as possible to disturb those leaves or the flower stalks.

In the days when gardening meant growing food for the table, cleaning out plant debris before winter was a routine practice to reduce the spread of diseases that affect vegetables. That routine carried over when suburbanites switched their yards to ornamental plants and turf grass, with the unfortunate consequence that we deprived our non-human neighbors of the shelter and food they need to survive. The tide is turning, though, as people are realizing that attractive gardens that support the ecosystem do better when their caretakers go easy on the autumn chores.

Some birds and nocturnal mammals are able to dig for grubs in a lawn, but you may have noticed that most friendly critters such as box turtles, frogs, and katydids do not spend a lot of time frolicking on your turf grass. It would leave them much too exposed, not to mention starving. Layers of leaves from native trees and shrubs, by contrast, provide a smorgasbord for them. Some of their meals consist of the caterpillars and other insects that feed on the leaves of native trees in spring and summer until they float down to the ground in the fall. Those that escape predation turn into adults the next spring and start the cycle over. Other insects such as fireflies spend their entire lives in the leaf litter, coming out briefly to find mates. All this assumes that their homes are not chopped up or raked up to be sent off to mulch factories.

Similarly, dead stalks provide shelter for many little critters, including certain species of native bees that burrow into the ends of broken stalks to lay their eggs.  Plants left intact enliven our yards all winter with their interesting seed heads and waving stems, made even more lively as the songbirds perch on the stalks and scrabble in the leaves for the seeds of flowers and grasses.

As the plants emerge again in the spring, they have no trouble pushing past the dead leaves, which act as a natural mulch until they gradually decompose and feed the soil. Many of the dead flower stalks will have fallen down by spring, and those remaining are quickly hidden from sight by the growing plants. If those plants are native to our ecosystem, they continue to provide benefits the rest of the year by nourishing the caterpillars and providing nectar and pollen for the pollinators. Some of the thicker leaves such as oaks may smother turf grass under the trees, but that is just as well, since mowing around trees risks injuries to their bark, and walking under them compacts the soil and stresses the roots. Trees do best when their leaves are left in place out to the drip line. But if that isn’t possible, try to move these leaves intact into other beds.  Mulching fallen leaves with the mower blade is better than sending them off in a truck or dumping smothering piles in the woods, but it may chop up the insect larvae and eggs.

Simple adjustments such as these to our landscaping practices will greatly improve the prospects of our local ecosystem. Other important steps to take include adding native plants, removing invasive non-native plants, minimizing the use of outdoor lighting, and eliminating mosquito spraying with its lethal consequences to the living world. Learn more on the Plant NOVA Natives website.

Tree-of-Heaven is Not Heavenly!

/in , /by

Photo: Plant NOVA Natives

Article by Cindy Speas, Chair, Fairfax County Tree Commission

In summer many folks travel to the Shenandoah Valley and beyond for recreational opportunities. Driving in any direction from Northern Virginia in the growing season, there is a tree that can be seen everywhere along the highways and byways. The dramatic clusters of seeds are so large they look like giant flowers among the leaves. It’s not native walnut or native sumac—it is Ailanthus altissima, commonly called Tree-of-Heaven. Disturbed areas and right of ways along roads are perfect locations for this opportunistic pest to colonize. Ailanthus is popping up in suburbia as well, and those of us who love trees wonder why experts are calling for us to remove these attractive and fast-growing specimens from our properties as soon as possible?

Ailanthus was imported from China and widely distributed in the United States as an ornamental in the late 1700s and 1800s. Its behavior, though, is far from heavenly—it spreads aggressively through root sprouting and huge seed production; it grows to maturity rapidly with a very long taproot; it is characterized by its terrible odor; and it poisons the ground around its roots with chemicals, in a process called allelopathy. This prevents native trees and plants from growing nearby, allowing Ailanthus to quickly spread and dominate our landscape.

Additionally, Ailanthus is the preferred food source for a new invasive insect—the Spotted Lanternfly (SLF). In spite of state quarantines, this destructive pest has now been found in Fairfax County. It is a major threat to some of Virginia’s agricultural areas, especially our vineyards, peach orchards and hops. It is also a threat to native tree species like oaks and maples that thrive in our yards. Forest Pest Branch asks all residents to report Ailanthus here and report Spotted Lanternfly sightings here.

Some may ask why these non-native trees should be removed—don’t they at least provide shade and shelter in a warming world? They certainly can, but they crowd out our native oaks, beeches, hickories and maples, as well as failing to provide the critical food resources that native insects and other animals need to live and reproduce in a fully functioning, healthy ecosystem. If a plant like this is killing off or threatening major parts of our local natural food web, the entire system will eventually collapse. And we will lose our native tree canopy along the way.

How can we stop the spread of this nasty invasive? The first thing, of course, is not to purchase it in the first place! So be sure to learn how to identify it. You can become familiar with the iNaturalist app on your smartphone or use other online resources to name the plant. The second is to remove the tree if it is growing on your land. This pest, however, thrives when simply cut down, so strategies must be used to kill the root system right away. There are some excellent resources to help landowners eliminate this threat safely and efficiently. Blue Ridge Prism has excellent fact sheets with details about herbicide use for this and other invasive species.

Visit Plant Nova Natives for more information about invasives and their destructive roles in our native environment. If we could eliminate a threat like the Tree-of-Heaven, that would truly be heavenly.

Want birds and butterflies? Plant native shrubs!

/in , /by

Photo: Courtesy Plant NOVA Natives/Plant NOVA Trees (Shrubby St. John’s Wort)

This month’s newsletter article to share from Plant NOVA Natives/Plant NOVA Trees

Want birds and butterflies?

Want birds and butterflies? Plant native shrubs! When it comes to the curb appeal of our houses and other buildings, the difference between starkly naked and softly clothed is the shrubs. What is a shrub, anyway? According to famous bird expert David Allen Sibley, “If you can walk under it, it’s a tree; if you have to walk around it, it’s a shrub.” Other than being multi-stemmed and relatively short, a shrub is pretty much the same as a tree and therefore provides the same environmental benefits, albeit to a smaller degree. And the difference between a native shrub and a non-native one is that the former will not only beautify a property but will turn it into a living landscape that supports the butterflies and birds.

Many people are looking at their yards and at public land and realizing that a lot of the space is being wasted. Turf grass has its advantages for certain purposes, such as providing a place to walk or play sports, but as a non-native plant, it does nothing for the ecosystem and requires a lot of input to maintain. Chipping away at the lawn with native shrubs can quickly cover the ground at a very low cost. Beyond the initial watering to get them established, they will require little or no maintenance from then on.

For small spaces, there are some native shrubs that naturally stay short, such as Shrubby Saint John’s Wort (Hypericum prolificum) with its bright yellow flowers. There are also smaller cultivars of larger shrubs, such as Winterberry Holly (Ilex verticillata) with its red berries that persist into January until they finally soften up and become a food source for hungry birds. If you use shrubs whose ultimate height fits the space you have in mind, the yearly shearing task will be eliminated. These and many other native shrubs are described on the Plant NOVA Natives website, which also points to places to buy them.

Some native shrubs grow tall enough to provide shade and can be an alternative to a small flowering tree. Common Witch-hazel is an example of that. The twigs have been used for divining rods, and the leaves get cute bumps in the shape of a witch’s hat. This native shrub is also magical for the flowers that are revealed in November after the leaves have fallen off. Those bumps, by the way, are caused by the reaction of the plant to a chemical injected by a tiny insect, the Witch-hazel Cone Gall Aphid. The cone-shaped bumps provide food and shelter to the female aphids as they lay their eggs.

Native shrubs can fill in the spaces between trees. From an environmental perspective, this arrangement is ideal, providing shelter and food at multiple heights, something we have lost in many of our woods to excessive browsing by deer. (In fact, although “Nature’s first green is gold,” if you look into the woods of Northern Virginia right now, there is a suspicious amount of green, much of which is due to invasive species such as Multiflora Rose and Asian Bush Honeysuckle. The leaves of invasive plants often emerge earlier and persist later than those of our native shrubs.) In our own yards, we can take steps to protect plants from deer and to swap out invasive shrubs for native ones and thus help support our local ecosystem.

The Virginia Department of Forestry (VDOF) is collecting data on how many trees are planted in Northern Virginia as it works toward the goal of 600,000 by 2025. For this purpose, shrubs count as trees, so VDOF is encouraging everyone to report plantings of both. A reporting form can be found on the Plant NOVA Trees website.