Prescribed Fire: Controlled Burns for Forest and Non-forest Habitats

Homo sapiens owes much of its success as a species to an acquired knowledge of how to make, control, and utilize fire.  Using fire to convert the energy stored in combustible materials into light and heat has enabled humankind to expand its range throughout the globe.  Indeed, humans in their furless incomplete mammalian state may have never been able to expand their populations outside of tropical latitudes without mastery of fire.  It is fire that has enabled man to exploit more of the earth’s resources than any other species.  From cooking otherwise unpalatable foods to powering the modern industrial society, fire has set man apart from the rest of the natural world.

In our modern civilizations, we generally look at the unplanned outbreak of fire as a catastrophe requiring our immediate intercession.  A building fire, for example, is extinguished as quickly as possible to save lives and property.  And fires detected in fields, brush, and woodlands are promptly controlled to prevent their exponential growth.  But has fire gone to our heads?  Do we have an anthropocentric view of fire?  Aren’t there naturally occurring fires that are essential to the health of some of the world’s ecosystems?  And to our own safety?  Indeed there are.  And many species and the ecosystems they inhabit rely on the periodic occurrence of fire to maintain their health and vigor.

For the war effort- The campaign to reduce the frequency of forest fires got its start during World War II with distribution of this poster in 1942.  The goal was to protect the nation’s timber resources from accidental or malicious loss due to fire caused by man-made ignition sources.  The release of the Walt Disney film “Bambi” during the same year and the adoption of the Smokey the Bear mascot in 1944 softened the message’s delivery, but the public relations outreach continued to be a key element of a no-fire policy to save trees for lumber.  Protection and management of healthy forest ecosystems in their entirety has only recently become a priority.  (National Archives image)

Man has been availed of the direct benefits of fire for possibly 40,000 years or more.  Here in the Lower Susquehanna River Watershed, the earliest humans arrived as early as 12,000 years ago—already possessing skills for using fire.  Native plants and animals on the other hand, have been part of the ever-changing mix of ecosystems found here for a much longer period of time—millions to tens of millions of years.  Many terrestrial native species are adapted to the periodic occurrence of fire.  Some, in fact, require it.  Most upland ecosystems need an occasional dose of fire, usually ignited by lightning (though volcanism and incoming cosmic projectiles are rare possibilities), to regenerate vegetation, release nutrients, and maintain certain non-climax habitat types.

But much of our region has been deprived of natural-type fires since the time of the clearcutting of the virgin forests during the eighteenth and nineteenth centuries.  This absence of a natural fire cycle has contributed to degradation and/or elimination of many forest and non-forest habitats.  Without fire, a dangerous stockpile of combustible debris has been collecting, season after season, in some areas for a hundred years or more.  Lacking periodic fires or sufficient moisture to sustain prompt decomposition of dead material, wildlands can accumulate enough leaf litter, thatch, dry brush, tinder, and fallen wood to fuel monumentally large forest fires—fires similar to those recently engulfing some areas of the American west.  So elimination of natural fire isn’t just a problem for native plants and animals, its a potential problem for humans as well.

Indiangrass on Fire
Indiangrass (seen here), Switchgrass, Big Bluestem, and Little Bluestem are native species requiring periodic forms of disturbance to eliminate competition by woody plants.  These warm-season grasses develop roots that penetrate deep into the soil, sometimes to depths of six feet or more, allowing them to survive severe drought and flash fire events.  In the tall grass prairies, these extensive root systems allow these grasses to return following heavy grazing by roaming herds of American Bison (Bison bison).  Without these habitat disturbances, warm season grasslands succumb to succession in about seven years.  With their periodic occurrence, the plants thrive and provide excellent wildlife habitat, erosion control, and grazing forage.

To address the habitat ailments caused by a lack of natural fires, federal, state, and local conservation agencies are adopting the practice of “prescribed fire” as a treatment to restore ecosystem health.  A prescribed fire is a controlled burn specifically planned to correct one or more vegetative management problems on a given parcel of land.  In the Lower Susquehanna River Watershed, prescribed fire is used to…

      • Eliminate dangerous accumulations of combustible fuels in woodlands.
      • Reduce accumulations of dead plant material that may harbor disease.
      • Provide top kill to promote oak regeneration.
      • Regenerate other targeted species of trees, wildflowers, grasses, and vegetation.
      • Kill non-native plants and promote growth of native plants.
      • Prevent succession.
      • Remove woody growth and thatch from grasslands.
      • Promote fire tolerant species of plants and animals.
      • Create, enhance, and/or manage specialized habitats.
      • Improve habitat for rare species (Regal Fritillary, etc.)
      • Recycle nutrients and minerals contained in dead plant material.

Let’s look at some examples of prescribed fire being implemented right here in our own neighborhood…

Prescribed Fire
Prescribed fires are typically planned for the dormant season extending from late fall into early spring with burns best conducted on days when the relative humidity is low.
Prescribed Fire at Fort Indiantown Gap
Prescribed fire is used regularly at Fort Indiantown Gap Military Reservation in Lebanon County, Pennsylvania, to keep accumulations of woody and herbaceous fuels from accumulating on and around the training range areas where live ordinance and other sources of ignition could otherwise spark large, hard-to-control wildfires.
Prescribed Fire at Fort Indiantown Gap
Prescribed fires replace the periodic natural burns that would normally reduce the fuel load in forested areas.  Where these fuels are allowed to accumulate, south-facing slopes are particularly susceptible to extreme fires due to their exposure to the drying effects of intense sunlight for much of the year.  The majority of small oaks subjected to treatment by the prescribed fire shown here will have the chance to regenerate without immediate competition from other species including invasive plants.  The larger trees are mostly unaffected by the quick exposure to the flames.  Note too that these fires don’t completely burn everything on the forest floor, they burn that which is most combustible.  There are still plenty of fallen logs for salamanders, skinks, and other animals to live beneath and within.

 

Prescribed fire in grassland.
A prescribed fire in late winter prevents this grassland consisting of Big Bluestem and native wildflowers from being overtaken by woody growth and invasive species.  Fires such as this that are intended to interrupt the process of succession are repeated at least every three to five years.
Prescribed Fire to Control Invasive Species
In its wildlife food plots, prescribed fire is used by the Pennsylvania Game Commission to prevent succession and control invasive species such as Multiflora Rose, instead promoting the growth of native plants.
A woodlot understory choked with combustible fuels and tangles of invasive Multiflora Rose.
An example of a woodlot understory choked with combustible fuels and dense tangles of invasive Multiflora Rose.  A forester has the option of prescribing a dose of dormant-season fire for a site like this to reduce the fuel load, top kill non-native vegetation, and regenerate native plants.
Precribed Fire to Eliminate Woody Growth
A dose of prescribed fire was administered on this grassland to kill the woody growth of small trees beginning to overtake the habitat by succession.
Precribed Fire Education Sign at middle creek Wildlife Management Area
The Pennsylvania Game Commission employs prescribed fire at Middle Creek Wildlife Management Area and on many of their other holdings to maintain grasslands.
Prescribed fire is used to eliminate invasive species including Multiflora Rose from grasslands at Middle Creek W.M.A.  Annual burns on the property are conducted in a mosaic pattern so that each individual area of the grassland is exposed to the effects of fire only once every two to five years.  Without fire or some type of mechanical or chemical intervention, succession by woody trees and shrubs would take hold after about seven years.
Prescribed fire is planned for a fraction of total grassland acreage at Middle Creek W.M.A. each year.  Another section of the mosaic is targeted in the following year and yet another in the year that follows that.  Because burns are conducted in the spring, grassland cover is available for wildlife throughout the winter.  And because each year’s fire burns only a portion of the total grassland acreage, wildlife still has plenty of standing grass in which to take shelter during and after the prescribed fire.
Grasshopper Sparrow
Prescribed fire at Middle Creek W.M.A. provides grassland habitat for dozens of species of birds and mammals including the not-so-common Grasshopper Sparrow…
Ring-necked Pheasant
…and stocked Ring-necked Pheasants that do nest and raise young there.
Prescribed Burn Maintains Savanna-like Habitat
On a few sites in the Lower Susquehanna River Watershed , prescribed fire is being used to establish and maintain savanna-like grasslands.  This one, located on a dry, south-facing slope near numerous man-made sources of ignition, can easily be dosed with periodic prescribed burns to both prevent succession and reduce fuel accumulations that may lead to a devastating extreme fire.
Pitch Pines in Savanna-like Habitat
One year following a prescribed burn, this is the autumn appearance of a savanna-like habitat with fire-tolerant Pitch Pine (Pinus rigida), Bear Oak, warm-season grasses, and a variety of nectar-producing wildflowers for pollinators.  These ecosystems are magnets for wildlife and may prove to be a manageable fit on sun-drenched sites adjacent to man-made land disturbances and their sources of ignition.
Red-headed Woodpecker Adult and Juvenile
Savanna-like grasslands with oaks and other scattered large trees, some of them dead, make attractive nesting habitat for the uncommon Red-headed Woodpecker.
Wild Turkey in Savanna-like Habitat
Prescribed fire can benefit hungry Wild Turkeys by maintaining savanna-like grasslands for an abundance of grasshoppers and other insects in summer and improving the success of mast-producing oaks for winter.
Buck Moth
In the Lower Susquehanna River Watershed, the caterpillar of the rare Eastern Buck Moth feeds on the foliage of the Bear Oak, also known as the Scrub Oak, a shrubby species that relies upon periodic fire to eliminate competition from larger trees in its early successional habitat.
Leaves of the Bear Oak in fall.
Leaves of the Bear Oak in fall.  The Bear Oak regenerates readily from top kill caused by fire.
Reed Canary Grass
Reed Canary Grass (Phalaris arundinacea) is a native cool-season grass with a colorful inflorescence in spring.  But given the right situation, it can aggressively overtake other species to create a pure stand lacking biodiversity.  It is one of the few native species which is sometimes labelled “invasive”.
Prescribed Burn to Reduce Prevalence of Reed Canary Grass
Prescribed fire can be used to reduce an overabundance of Reed Canary Grass and its thatch in wetlands.  Periodic burning can help restore species diversity in these habitats for plants and animals including rare species such as the endangered Bog Turtle (Glyptemys muhlenbergii).
On the range areas at Fort Indiantown Gap in Lebanon County, Pennsylvania, disturbances by armored vehicles mimic the effects of large mammals such as the American Bison which periodically trampled grasses to prevent succession and the establishment of woody plants on its prairie habitat.  To supplement the activity of the heavy vehicles and to provide suitable habitat for the very rare Regal Fritillary (Speyeria idalia) butterflies found there, prescribed fire is periodically employed to maintain the grasslands on the range.  These burns are planned to encourage the growth of “Fort Indiantown Gap Little Bluestem” grass as well as the violets used as host plants by the Regal Fritillary caterpillars.  These fires also promote growth of a variety of native summer-blooming wildflowers to provide nectar for the adults butterflies.
Depiction of Pennsylvania's Last American Bison, Killed in Union County in 1801. (Exhibit: State Museum of Pennsylvania, Harrisburg)
A last record of a wild American Bison killed in Pennsylvania was an animal taken in the Susquehanna watershed in Union County in 1801.  The species is thereafter considered extirpated from the state.  Since that time, natural disturbances needed to regenerate warm-season grasses have been limited primarily to fires and riverine ice scour.  The waning occurrence of both has reduced the range of these grasses and their prairie-like ecosystems in the commonwealth.  (Exhibit: State Museum of Pennsylvania, Harrisburg)
A male Regal Fritillary on the range at Fort Indiantown Gap, where armored vehicles and prescribed fire provide suitable prairie-like habitat for this vulnerable species.
Honey Bee Collecting Minerals After Prescribed Burn
Prescribed fires return the nutrients and minerals contained in dead plant material to the soil.  Following these controlled burns, insects like this Honey Bee can often be seen collecting minerals from the ashes.
Fly Collecting Minerals from Burned Grasses
A Greenbottle Fly gathering minerals from the ash following a prescribed burn.

In Pennsylvania, state law provides landowners and crews conducting prescribed fire burns with reduced legal liability when the latter meet certain educational, planning, and operational requirements.  This law may help encourage more widespread application of prescribed fire in the state’s forests and other ecosystems where essential periodic fire has been absent for so very long.  Currently in the Lower Susquehanna River Watershed, prescribed fire is most frequently being employed by state agencies on state lands—in particular, the Department of Conservation and Natural Resources on State Forests and the Pennsylvania Game Commission on State Game Lands.  Prescribed fire is also part of the vegetation management plan at Fort Indiantown Gap Military Reservation and on the land holdings of the Hershey Trust.  Visitors to the nearby Gettysburg National Military Park will also notice prescribed fire being used to maintain the grassland restorations there.

For crews administering prescribed fire burns, late March and early April are a busy time.  The relative humidity is often at its lowest level of the year, so the probability of ignition of previous years’ growth is generally at its best.  We visited with a crew administering a prescribed fire at Middle Creek Wildlife Management Area last week.  Have a look…

Members of a Pennsylvania Game Commission burn crew provide visitors to Middle Creek Wildlife Management Area with an overview of prescribed fire.
Members of a Pennsylvania Game Commission burn crew provide visitors to Middle Creek Wildlife Management Area with an overview of prescribed fire and the equipment and techniques they use to conduct a burn.
Burn Boss Checking Weather
Pennsylvania Game Commission Southeast Region Forester Andy Weaver will fulfill the role of Burn Boss for administering this day’s dose of fire.  His responsibilities include assessing the weather before the burn and calculating a probability of ignition.
Burn Boss Briefing Crew
The Burn Boss briefs personnel with information on site layout, water supply location(s), places of refuge, emergency procedures, the event’s goals and plan of action, crew assignments, and the results of the weather check: wind from the northwest at 5 miles per hour, temperature 48 degrees, and the relative humidity 63%. Today’s patient is a parcel of warm-season grasses receiving a dose of fire to eliminate invasive non-native plants, woody growth, and thatch.  The probability of ignition is 20%, but improving by the minute.
Prescribed Fire Test Burn
To begin the burn, a test fire is started in the downwind corner of the parcel, which also happens to be the bottom of the slope.  Fuel ignition is good.  The burn can proceed.
Igniting the Fire
Crews proceed uphill from the location of the test fire while igniting combustibles along both flanks of the area being treated.
Prescribed Fire Crew Member with Equipment
A drip torch is used to ignite the dried stems and leaves of warm-season grasses and wildflowers.  Each member of the burn crew wears Nomex fire-resistant clothing and carries safety equipment including a two-way radio, a hydration pack, and a cocoon-like emergency fire shelter.
Wildfire ATV
An all-terrain vehicle equipped with various tools, a fire pump, hose, and a small water tank accompanies the crew on each flank of the fire.
Prescribed Fire
A mowed strip of cool-season grasses along the perimeter of the burn area is already green and functions as an ideal fire break.  While the drip torch is perfect for lighting combustibles along the fire’s perimeter, the paintball gun-looking device is an effective tool used to lob incendiaries into the center areas of the burn zone for ignition.
Effective Fire Break
With green cool-season grasses already growing on the trails surrounding the burn zone, very little water was used to contain this prescribed fire.  Where such convenient fire breaks don’t already exist, crews carry tools including chain saws, shovels, and leaf blowers to create their own.  They also carry flame swatters, backpack water pumps, shovels, and other tools to extinguish fires if necessary.  None of these items were needed to control this particular fire.
Halting the Process of Succession in a Grassland with Prescribed Fire
This fast-burning fire provides enough heat to damage the cambium layer of the woody tree and shrub saplings in this parcel being maintained as a grassland/wildflower plot, thus the process of succession is forestalled.  Burns conducted during previous years on this and adjacent fields have also controlled aggressive growth of invasive Multiflora Rose and Olives (Elaeagnus species).
Containing the Fire on the Flanks
Crews proceed up the slope while maintaining the perimeter by igniting dry plant material along the flanks of the burn zone.
The Crew Monitors the Burn
Ignition complete, the crews monitor the fire.
Prescribed Fire: Natural Mosaic-style Burn Pattern
The Burn Boss surveys the final stages of a safe and successful prescribed fire.  The fire has left behind a mosaic of burned and unburned areas, just as a naturally occurring event may have done.  Wildlife dodging the flames may be taking refuge in the standing grasses, so there is no remedial attempt to go back and ignite these areas.  They’ll be burned during prescribed fires in coming years.
Great Spangled Fritillary
By June, this grassland will again be lush and green with warm-season grasses and blooming wildflowers like this Common Milkweed being visited by a Great Spangled Fritillary.
Eastern Tiger Swallowtails on Joe-pye Weed.
And later in the summer, Eastern Tiger Swallowtails on Joe-pye Weed.
Indiangrass in flower in mid-summer.
Indiangrass in flower in mid-summer.
Bobolinks in Indiangrass
Bobolinks glow in the late August sun while taking flight from a stand of warm-season grasses maintained using springtime prescribed fire.  The small dots on the dark background at the top of the image are multitudes of flying insects, many of them pollinators.  The vegetation is predominately Indiangrass, excellent winter cover for birds, mammals, and other wildlife.

Prescribed burns aren’t a cure-all for what ails a troubled forest or other ecosystem, but they can be an effective remedy for deficiencies caused by a lack of periodic episodes of naturally occurring fire.  They are an important option for modern foresters, wildlife managers, and other conservationists.

Time to Order Trees and Shrubs for Spring

It’s that time of year.  Your local county conservation district is taking orders for their annual tree sale and it’s a deal that can’t be beat.  Order now for pickup in April.

The prices are a bargain and the selection includes the varieties you need to improve wildlife habitat and water quality on your property.  For species descriptions and more details, visit each tree sale web page (click the sale name highlighted in blue).  And don’t forget to order packs of evergreens for planting in mixed clumps and groves to provide winter shelter and summertime nesting sites for our local native birds.  They’re only $12.00 for a bundle of 10.

Mature Trees in a Suburban Neighborhood
It’s the most desirable block in town, not because the houses are any different from others built during the post-war years of the mid-twentieth century, but because the first owners of these domiciles had the good taste and foresight to plant long-lived trees on their lots, the majority of them native species.  Pin Oak, Northern Red Oak, Yellow Poplar, Flowering Dogwood (Cornus florida), Eastern Red Cedar, Eastern White Pine, Eastern Hemlock, Norway Spruce, and American Holly dominate the landscape and create excellent habitat for birds and other wildlife.  These 75-year-old plantings provide an abundance of shade in summer and thermal stability in winter, making it a “cool” place to live or take a stroll at any time of the year.

Cumberland County Conservation District Annual Tree Seedling Sale—

Orders due by: Friday, March 22, 2024

Pickup on: Thursday, April 18, 2024 or Friday, April 19, 2024

Common Winterberry
Cumberland County Conservation District is taking orders for Common Winterberry, the ideal small shrub for wet soil anywhere on your property.  To get berries, you’ll need both males and females, so buy a bunch and plant them in a clump or scattered group.
Pin Oak
To live for a century or more like this towering giant, a Pin Oak needs to grow in well-drained soils with adequate moisture.  These sturdy shade providers do well along streams and on low ground receiving clean runoff from hillsides, roofs, streets, and parking areas.  As they age, Pin Oaks can fail to thrive and may become vulnerable to disease in locations where rainfall is not adequately infiltrated into the soil.  Therefore, in drier areas such as raised ground or slopes, avoid the Pin Oak and select the more durable Northern Red Oak for planting.  This year, Pin Oaks are available from the Cumberland and Lancaster County Conservation Districts, while Dauphin, Lancaster, Lebanon, and York Counties are taking orders for Northern Red Oaks.
Purple Coneflower
The Cumberland County Conservation District is again offering a “Showy Northeast Native Wildflower and Grass Mix” for seeding your own pollinator meadow or garden.  It consists of more than twenty species including this perennial favorite, Purple Coneflower.

Dauphin County Conservation District Seedling Sale—

Orders due by: Monday, March 18, 2024

Pickup on: Thursday, April 18, 2024 or Friday, April 19, 2024

Eastern Redbud
The Eastern Redbud is small tree native to our forest edges, particularly in areas of the Piedmont Province with Triassic geology (Furnace Hills, Conewago Hills, Gettysburg/Hammer Creek Formations, etc.)  Also known as the Judas Tree, the redbud’s brilliant flowers are followed by heart-shaped leaves.  As seen here, it is suitable for planting near houses and other buildings.  Eastern Redbud seedlings are being offered through tree sales in Dauphin, Cumberland, and Lancaster Counties.

Lancaster County Annual Tree Seedling Sale—

Orders due by: Friday, March 8, 2024

Pickup on: Friday, April 12, 2024

Yellow Poplar
The Yellow Poplar, often called Tuliptree or Tulip Poplar for its showy flowers, is a sturdy, fast-growing deciduous tree native to forests throughout the Lower Susquehanna River Watershed.  Its pole-straight growth habit in shady woodlands becomes more spreading and picturesque when the plant is grown as a specimen or shade tree in an urban or suburban setting.  The Yellow Poplar can live for hundreds of years and is a host plant for the Eastern Tiger Swallowtail butterfly.  It is available this year from the Lancaster County Conservation District.
The American Sweetgum, also known as Sweet Gum, is a large, long-lived tree adorned with a mix of vibrant colors in autumn.
American Goldfinches and Pine Siskin on Sweet Gum
Ever wonder where all the American Goldfinches and particularly the Pine Siskins go after passing through our region in fall?  Well, many are headed to the lowland forests of the Atlantic Coastal Plain where they feed on an abundance of seeds contained in spiky American Sweetgum fruits.  In the Piedmont and Ridge and Valley Provinces of the Lower Susquehanna River Watershed, American Sweetgum transplants can provide enough sustenance to sometimes lure our friendly finches into lingering through the winter.
Sweet Gum in a Beaver Pond
The American Sweetgum is a versatile tree.  It can be planted on upland sites as well as in wet ground along streams, lakes, and rivers.  In the beaver pond seen here it is the dominate tree species.  This year, you can buy the American Sweetgum from the Lancaster County Conservation District.
"Red-twig Dogwood"
“Red-twig Dogwood” is a group of similar native shrubs that, in our region, includes Silky Dogwood and the more northerly Red-Osier Dogwood (Cornus sericea).  Both have clusters of white flowers in spring and showy red twigs in winter.  They are an excellent choice for wet soils.  Landscapers often ruin these plants by shearing them off horizontally a foot or two from the ground each year.  To produce flowers and fruit, and to preserve winter attractiveness, trim them during dormancy by removing three-year-old and older canes at ground level, letting younger growth untouched.
Silky Dogwood Stream Buffer
“Red-twig Dogwoods” make ideal mass plantings for streamside buffers and remain showy through winter, even on a gloomy day.  They not only mitigate nutrient and sediment pollution, they provide excellent food and cover for birds and other wildlife.  Both Silky and Red-osier Dogwoods are available for sale through the Lancaster County Conservation District as part of their special multi-species offers, the former is included in its “Beauty Pack” and the latter in its “Wildlife Pack”.  The similar Gray Dogwood (Cornus racemosa) is being offered for sale by the York County Conservation District.

Lebanon County Conservation District Tree and Plant Sale—

Orders due by: Friday, March 8, 2024

Pickup on: Friday, April 19, 2024

Common Pawpaw flower
The unique maroon flowers of the Common Pawpaw produce banana-like fruits in summer.  These small native trees grow best in damp, well-drained soils on slopes along waterways, where they often form clonal understory patches.  To get fruit, plant a small grove to increase the probability of pollination.  The Common Pawpaw is a host plant for the Zebra Swallowtail butterfly.  It is available through both the Lebanon and Lancaster County sales.
Eastern Red Cedar
The Eastern Red Cedar provides excellent food, cover, and nesting sites for numerous songbirds.  Planted in clumps of dozens or groves of hundreds of trees, they can provide winter shelter for larger animals including deer and owls.  The Eastern Red Cedar is being offered for purchase through both the Lebanon and Lancaster County Conservation Districts.
Hybrid American Chestnut
Care to try your hand at raising some chestnuts?  Lebanon County Conservation District has hybrid American Chestnut seedlings for sale.
Common Winterberry
Lebanon County Conservation District is offering Common Winterberry and Eastern White Pine during their 2024 Tree and Plant Sale.  Plant them both for striking color during the colder months.  Eastern White Pine is also available from the Cumberland, Dauphin, Lancaster, and York County sales.

Perry County Conservation District Tree Sale—

Orders due by: Sunday, March 24, 2024

Pickup on: Thursday, April 11, 2024

Pollinator Garden
In addition to a selection of trees and shrubs, the Perry County Conservation District is again selling wildflower seed mixes for starting your own pollinator meadow or garden.  For 2024, they have both a “Northeast Perennials and Annuals Mix” and a “Butterfly and Hummingbird Seed Mix” available.  Give them a try so you can give up the mower!

Again this year, Perry County is offering bluebird nest boxes for sale.  The price?—just $12.00.

Eastern Bluebird
Wait, what?,…twelve bucks,…that’s cheaper than renting!

York County Conservation District Seedling Sale—

Orders due by: Friday, March 15, 2024

Pickup on: Thursday, April 11, 2024

Buttonbush flower
The Buttonbush, a shrub of wet soils, produces a cosmic-looking flower.  It grows well in wetlands, along streams, and in rain gardens.  Buttonbush seedlings are for sale from both the York and Lancaster County Conservation Districts.

To get your deciduous trees like gums, maples, oaks, birches, and poplars off to a safe start, conservation district tree sales in Cumberland, Dauphin, Lancaster, and Perry Counties are offering protective tree shelters.  Consider purchasing these plastic tubes and supporting stakes for each of your hardwoods, especially if you have hungry deer in your neighborhood.

Deciduous Tree Planting Protected by Shelters
Tree shelters protect newly transplanted seedlings from browsing deer, klutzy hikers, visually impaired mower operators, and other hazards.

There you have it.  Be sure to check out each tree sale’s web page to find the selections you like, then get your order placed.  The deadlines will be here before you know it and you wouldn’t want to miss values like these!

Butterflies and More at Boyd Big Tree Preserve Conservation Area

If you’re feeling the need to see summertime butterflies and their numbers just don’t seem to be what they used to be in your garden, then plan an afternoon visit to the Boyd Big Tree Preserve along Fishing Creek Valley Road (PA 443) just east of U.S. 22/322 and the Susquehanna River north of Harrisburg.  The Pennsylvania Department of Conservation and Natural Resources manages the park’s 1,025 acres mostly as forested land with more than ten miles of trails.  While located predominately on the north slope of Blue Mountain, a portion of the preserve straddles the crest of the ridge to include the upper reaches of the southern exposure.

American Chestnut at Boyd Big Tree Preserve
A grove of American Chestnuts (Castanea dentata) planted at Boyd Big Tree Preserve is part of a propagation program working to restore blight-resistant trees to Pennsylvania and other areas of their former range which included the Appalachians and the upper Ohio River watershed.

Fortunately, one need not take a strenuous hike up Blue Mountain to observe butterflies.  Open space along the park’s quarter-mile-long entrance road is maintained as a rolling meadow of wildflowers and cool-season grasses that provide nectar for adult butterflies and host plants for their larvae.

Butterfly Meadow at Boyd Big Tree Preserve
A view looking north at the butterfly meadow and entrance road at Boyd Big Tree Preserve Conservation Area.  Second Mountain is in the background.
Walking a Meadow Path
Mowed paths follow the entrance road and a portion of the perimeter of the meadow allowing visitors a chance to wander among the waist-high growth to see butterflies, birds, and blooming plants at close range without trampling the vegetation or risking exposure to ticks.
A Silver-spotted Skipper feeding on nectar from Dogbane (Apocynum cannabinum) flowers.
A Silver-spotted Skipper feeding on nectar from the flowers of Indian Hemp (Apocynum cannabinum).  Like the milkweeds, Indian Hemp is a member of the dogbane family (Apocynaceae).
An Eastern Tiger Swallowtail feeding on Common Milkweed.
An Eastern Tiger Swallowtail feeding on Common Milkweed.
Great Spangled Fritillary on Common Milkweed.
A Great Spangled Fritillary (Speyeria cybele) on Common Milkweed.
A Black Swallowtail feeding on Common Milkweed nectar.
A Black Swallowtail (Papilio polyxenes) feeding on Common Milkweed nectar.
A Pipevine Swallowtail on Common Milkweed.
A Pipevine Swallowtail (Battus philenor) on Common Milkweed.
A Pipevine Swallowtail on Common Milkweed.
Another Pipevine Swallowtail on Common Milkweed.  Note the hook-shaped row of red-orange spots on the underside of the hindwing.
A Pipevine Swallowtail on visiting Butterfly Weed.
A Pipevine Swallowtail visiting the brilliant blooms of Butterfly Weed, a favorite of a wide variety of pollinators.
A Black Swallowtail on Butterfly Weed
A Black Swallowtail with damaged wings alights atop a Butterfly Weed flower cluster.  Note the pair of parallel rows of red-orange spot on the underside of the hindwing.
A Monarch on Butterfly Weed
A Monarch feeding on nectar from the flowers of Butterfly Weed.
A mating pair of Eastern Tailed Blues.
A mating pair of Eastern Tailed Blues on a Timothy (Phleum pratense) spike.
A female (left) and male Great Spangled Fritillary.
A male Great Spangled Fritillary (right) pursuing a female.
Common Green Darner
Butterflies aren’t the only colorful insects patrolling the meadows at Boyd Big Tree Preserve.  Dragonflies including Common Green Darners are busily pursuing prey, particularly small flying insects like mosquitos, gnats, and flies.
Juvenile Broad-winged Hawk
Dragonflies themselves can become prey and are much sought after by Broad-winged Hawks. This very vocal juvenile gave us several good looks as it ventured from the forest into the skies above the upper meadow during midday.  It wasn’t yet a good enough flier to snag a dragonfly, but it will have plenty of opportunities for practice during its upcoming fall migration which, for these Neotropical raptors, will get underway later this month.

Do yourself a favor and take a trip to the Boyd Big Tree Preserve Conservation Area.  Who knows?  It might actually inspire you to convert that lawn or other mowed space into much-needed butterfly/pollinator habitat.

While you’re out, you can identify your sightings using our photographic guide—Butterflies of the Lower Susquehanna River Watershed—by clicking the “Butterflies” tab at the top this page.  And while you’re at it, you can brush up on your hawk identification skills ahead of the upcoming migration by clicking the “Hawkwatcher’s Helper: Identifying Bald Eagles and other Diurnal Raptors” tab.  Therein you’ll find a listing and descriptions of hawk watch locations in and around the lower Susquehanna region.  Plan to visit one or more this autumn!

Monarch an Endangered Species: What You Can Do Right Now

This month, the International Union for Conservation of Nature (I.U.C.N.) added the Migratory Monarch Butterfly (Danaus plexippus plexippus) to its “Red List of Threatened Species”, classifying it as endangered.  Perhaps there is no better time than the present to have a look at the virtues of replacing areas of mowed and manicured grass with a wildflower garden or meadow that provides essential breeding and feeding habitat for Monarchs and hundreds of other species of animals.

Monarch on Common Milkweed Flower Cluster
A recently arrived Monarch visits a cluster of fragrant Common Milkweed flowers in the garden at the susquehannawildlife.net headquarters.  Milkweeds included among a wide variety of plants in a garden or meadow habitat can help local populations of Monarchs increase their numbers before the autumn flights to wintering grounds commence in the fall.  Female Monarchs lay their eggs on milkweed leaves, then, after hatching, the larvae (caterpillars) feed on them before pupating.

If you’re not quite sure about finally breaking the ties that bind you to the cult of lawn manicuring, then compare the attributes of a parcel maintained as mowed grass with those of a space planted as a wildflower garden or meadow.  In our example we’ve mixed native warm season grasses with the wildflowers and thrown in a couple of Eastern Red Cedars to create a more authentic early successional habitat.

Comparison of Mowed Grass to Wildflower Meadow
* Particularly when native warm-season grasses are included (root depth 6′-8′)

Still not ready to take the leap.  Think about this: once established, the wildflower planting can be maintained without the use of herbicides or insecticides.  There’ll be no pesticide residues leaching into the soil or running off during downpours.  Yes friends, it doesn’t matter whether you’re using a private well or a community system, a wildflower meadow is an asset to your water supply.  Not only is it free of man-made chemicals, but it also provides stormwater retention to recharge the aquifer by holding precipitation on site and guiding it into the ground.  Mowed grass on the other hand, particularly when situated on steep slopes or when the ground is frozen or dry, does little to stop or slow the sheet runoff that floods and pollutes streams during heavy rains.

What if I told you that for less than fifty bucks, you could start a wildflower garden covering 1,000 square feet of space?  That’s a nice plot 25′ x 40′ or a strip 10′ wide and 100′ long along a driveway, field margin, roadside, property line, swale, or stream.  All you need to do is cast seed evenly across bare soil in a sunny location and you’ll soon have a spectacular wildflower garden.  Here at the susquehannawildllife.net headquarters we don’t have that much space, so we just cast the seed along the margins of the driveway and around established trees and shrubs.  Look what we get for pennies a plant…

Wildflower Garden
Some of the wildflowers and warm-season grasses grown from scattered seed in the susquehannawildlife.net headquarters garden.

Here’s a closer look…

Lance-leaved Coreopsis
Lance-leaved Coreopsis (Coreopsis lanceolata), a perennial.
Black-eyed Susan
Black-eyed Susan, a biennial or short-lived perennial.
Black-eyed Susan "Gloriosa Daisy"
“Gloriosa Daisy”, a variety of Black-eyed Susan, a biennial or short-lived perennial.
Purple Coneflower
Purple Coneflower, an excellent perennial for pollinators.  The ripe seeds provide food for American Goldfinches.
Common Sunflower
A short variety of Common Sunflower, an annual and a source of free bird seed.
Common Sunflower
Another short variety of Common Sunflower, an annual.

All this and best of all, we never need to mow.

Around the garden, we’ve used a northeast wildflower mix from American Meadows.  It’s a blend of annuals and perennials that’s easy to grow.  On their website, you’ll find seeds for individual species as well as mixes and instructions for planting and maintaining your wildflower garden.  They even have a mix specifically formulated for hummingbirds and butterflies.

Annuals in bloom
When planted in spring and early summer, annuals included in a wildflower mix will provide vibrant color during the first year.  Many varieties will self-seed to supplement the display provided by biennials and perennials in subsequent years.
Wildflower Seed Mix
A northeast wildflower mix from American Meadows.  There are no fillers.  One pound of pure live seed easily plants 1,000 square feet.

Nothing does more to promote the spread and abundance of non-native plants, including invasive species, than repetitive mowing.  One of the big advantages of planting a wildflower garden or meadow is the opportunity to promote the growth of a community of diverse native plants on your property.  A single mowing is done only during the dormant season to reseed annuals and to maintain the meadow in an early successional stage—preventing reversion to forest.

For wildflower mixes containing native species, including ecotypes from locations in and near the Lower Susquehanna River Watershed, nobody beats Ernst Conservation Seeds of Meadville, Pennsylvania.  Their selection of grass and wildflower seed mixes could keep you planting new projects for a lifetime.  They craft blends for specific regions, states, physiographic provinces, habitats, soils, and uses.  Check out these examples of some of the scores of mixes offered at Ernst Conservation Seeds

      • Pipeline Mixes
      • Pasture, Grazing, and Hay Mixes
      • Cover Crops
      • Pondside Mixes
      • Warm-season Grass Mixes
      • Retention Basin Mixes
      • Wildlife Mixes
      • Pollinator Mixes
      • Wetland Mixes
      • Floodplain and Riparian Buffer Mixes
      • Rain Garden Mixes
      • Steep Slope Mixes
      • Solar Farm Mixes
      • Strip Mine Reclamation Mixes

We’ve used their “Showy Northeast Native Wildflower and Grass Mix” on streambank renewal projects with great success.  For Monarchs, we really recommend the “Butterfly and Hummingbird Garden Mix”.  It includes many of the species pictured above plus “Fort Indiantown Gap” Little Bluestem, a warm-season grass native to Lebanon County, Pennsylvania, and milkweeds (Asclepias), which are not included in their northeast native wildflower blends.  More than a dozen of the flowers and grasses currently included in this mix are derived from Pennsylvania ecotypes, so you can expect them to thrive in the Lower Susquehanna River Watershed.

Swamp Milkweed
Swamp Milkweed, a perennial species, is included in the Ernst Seed “Butterfly and Hummingbird Garden Mix”.  It is a favorite of female Monarchs seeking a location to deposit eggs.
Monarch Caterpillar feeding on Swamp Milkweed
A Monarch larva (caterpillar) feeding on Swamp Milkweed.
Butterfly Weed
Butterfly Weed (Asclepias tuberosa) is included in the Ernst Seed “Butterfly and Hummingbird Garden Mix”.  This perennial is also known as Butterfly Milkweed.
Tiger Swallowtails visiting Butterfly Weed
Eastern Tiger Swallowtails are among the dozens of species of pollinators that will visit Butterfly Weed.

In addition to the milkweeds, you’ll find these attractive plants included in Ernst Conservation Seed’s “Butterfly and Hummingbird Garden Mix”, as well as in some of their other blends.

Wild Bergamot
The perennial Wild Bergamot, also known as Bee Balm, is an excellent pollinator plant, and the tubular flowers are a favorite of hummingbirds.
Oxeye
Oxeye is adorned with showy clusters of sunflower-like blooms in mid-summer.  It is a perennial plant.
Plains Coreopsis
Plains Coreopsis (Coreopsis tinctoria), also known as Plains Tickseed, is a versatile annual that can survive occasional flooding as well as drought.
Gray-headed Coneflower
Gray-headed Coneflower (Ratibida pinnata), a tall perennial, is spectacular during its long flowering season.
Monarch on goldenrod.
Goldenrods are a favorite nectar plant for migrating Monarchs in autumn.  They seldom need to be sown into a wildflower garden; the seeds of local species usually arrive on the wind.  They are included in the “Butterfly and Hummingbird Garden Mix” from Ernst Conservation Seeds in low dose, just in case the wind doesn’t bring anything your way.
Partridge Pea
Is something missing from your seed mix?  You can purchase individual species from the selections available at American Meadows and Ernst Conservation Seeds.  Partridge Pea is a good native annual to add.  It is a host plant for the Cloudless Sulphur butterfly and hummingbirds will often visit the flowers.  It does really well in sandy soils.
Indiangrass in flower.
Indiangrass is a warm-season species that makes a great addition to any wildflower meadow mix.  Its deep roots make it resistant to drought and ideal for preventing erosion.

Why not give the Monarchs and other wildlife living around you a little help?  Plant a wildflower garden or meadow.  It’s so easy, a child can do it.

Planting a riparian buffer with wildflowers and warm-season grasses
Volunteers sow a riparian buffer on a recontoured stream bank using wildflower and warm-season grass seed blended uniformly with sand.  By casting the sand/seed mixture evenly over the planting site, participants can visually assure that seed has been distributed according to the space calculations.
Riparian Buffer of wildflowers
The same seeded site less than four months later.
Monarch Pupa
A Monarch pupa from which the adult butterfly will emerge.

Fussy Eaters

She ate only toaster pastries…that’s it…nothing else.  Every now and then, on special occasions, when a big dinner was served, she’d have a small helping of mashed potatoes, no gravy, just plain, thank you.  She received all her nutrition from several meals a week of macaroni and cheese assembled from processed ingredients found in a cardboard box.  It contains eight essential vitamins and minerals, don’t you know?  You remember her, don’t you?

Adult female butterflies must lay their eggs where the hatched larvae will promptly find the precise food needed to fuel their growth.  These caterpillars are fussy eaters, with some able to feed upon only one particular species or genus of plant to grow through the five stages, the instars, of larval life.  The energy for their fifth molt into a pupa, known as a chrysalis, and metamorphosis into an adult butterfly requires mass consumption of the required plant matter.  Their life cycle causes most butterflies to be very habitat specific.  These splendid insects may visit the urban or suburban garden as adults to feed on nectar plants, however, successful reproduction relies upon environs which include suitable, thriving, pesticide-free host plants for the caterpillars.  Their survival depends upon more than the vegetation surrounding the typical lawn will provide.

The Monarch (Danaus plexippus), a butterfly familiar in North America for its conspicuous autumn migrations to forests in Mexico, uses the milkweeds (Asclepias) almost exclusively as a host plant.  Here at  Conewago Falls, wetlands with Swamp Milkweed (Asclepias incarnata) and unsprayed clearings with Common Milkweed (A. syriaca) are essential to the successful reproduction of the species.  Human disturbance, including liberal use of herbicides, and invasive plant species can diminish the biomass of the Monarch’s favored nourishment, thus reducing significantly the abundance of the migratory late-season generation.

Monarch caterpillar after a fourth molt.  The fifth instar feeding on Swamp Milkweed.
A fifth molt begets the Monarch pupa, the chrysalis, from which the showy adult butterfly will emerge.
Adult Monarch feeding on Goldenrod (Solidago) nectar.

Butterflies are good indicators of the ecological health of a given environment.  A diversity of butterfly species in a given area requires a wide array of mostly indigenous plants to provide food for reproduction.  Let’s have a look at some of the species seen around Conewago Falls this week…

An adult Silvery Checkerspot (Chlosyne nycteis) visiting a nectar plant, Partridge Pea (Chamaecrista fasciculata).  Wingstem (Verbesina alternifolia), a plant of the Riparian Woodlands, is among the probable hosts for the caterpillars.
A Gray Hairstreak (Strymon melinus) visits Crown Vetch, a possible host plant.  Other potential larval food in the area includes Partridge Pea, Halberd-leaved Rose Mallow (Hibiscus laevis) of the river shoreline, and Swamp Rose Mallow (Hibiscus moscheutos), a plant of wetlands.
The Eastern Tailed Blue (Cupido comyntas) may use Partridge Pea , a native wildflower species, and the introduced Crown Vetch (Securigera/Coronilla varia) as host and nectar plants at Conewago Falls.
The Least Skipper (Ancyloxypha numitor) is at home among tall grasses in woodland openings, at riverside, and in the scoured grassland habitat of the Pothole Rocks in the falls.  Host plants available include Switchgrass (Panicum vigatum), Freshwater Cordgrass (Spartina pectinata), and Foxtails (Setaria).
The Zabulon Skipper (Poanes zabulon) is an inhabitant of moist clearings where the caterpillars may feed upon Lovegrasses (Eragrostis) and Purpletop (Tridens flavus).
The Eastern Tiger Swallowtail (Papilio glaucus), a female seen here gathering nectar from Joe-Pye Weed (Eutrochium), relies upon several forest trees as hosts. Black Cherry (Prunus serotina), Willow (Salix), Yellow Poplar (Liriodendron tulipifera), also known as Tuliptree, and Green Ash (Fraxinus pennsylvanica) are among the local species known to be used.  The future of the latter food species at Conewago Falls is doubtful.  Fortunately for the Eastern Tiger Swallowtail, the “generalist” feeding requirements of this butterfly’s larvae enable the species to survive the loss of a host plant.
A female Eastern Tiger Swallowtail, black morph, gathering nectar from Joe-Pye Weed.
The Zebra Swallowtail (Protographium marcellus), an adult seen here on Joe-Pye Weed, feeds exclusively upon Pawpaw (Asimina) trees as a caterpillar.  This butterfly species may wander, but its breeding range is limited to the moist Riparian Woodlands where colonial groves of Pawpaw may be found.  The Common Pawpaw (Asimina triloba), our native species in Pennsylvania, and the Zebra Swallowtail occur at the northern edge of their geographic ranges in the Lower Susquehanna River Watershed.  Planting Pawpaw trees as an element of streamside reforestation projects certainly benefits this marvelous butterfly.

The spectacularly colorful butterflies are a real treat on a hot summer day.  Their affinity for showy plants doubles the pleasure.

By the way, I’m certain by now you’ve recalled that fussy eater…and how beautiful she grew up to be.

SOURCES

Brock, Jim P., and Kaufman, Kenn.  2003.  Butterflies of North America.  Houghton Mifflin Company.  New York, NY.