HUNTERS POINT: AN ECO-SOTRY VIRTUAL EXHIBIT
* Source: Queens Public Library
1. Marine Wildlife
2. Maritime Uses in New York City
3. Investing for the Future of a Healthier Harbor
4. New York City’s Tidal Ecosystem: Harbor Estuary
5. New York City before Colonization: Local Indigenous History
6. The Forces that Shape the Harbor: NYC Geology
7. Water Quality
8. Local Industry and It’s Relationship to the Waterways
Biodiversity & Species Conservation: https://dec.ny.gov/nature/animals-fish-plants/biodiversity-species-conservation
List of Endangered, Threatened and Special Concern Fish and Wildlife Species of New York State: https://dec.ny.gov/nature/animals-fish-plants/biodiversity-species-conservation/endangered-species/list
Special thanks to Hunters Point Parks Conservancy for their partnership for Umbilical City.
Urban Ecology in Hunters Point Parks, Long Island City, New York
* Source: Hunters Point Parks Conservancy, Long Island City, NY. Since 1998, HPPC has been working to support our waterfront parks through stewardship, volunteering, advocacy, and programming.
Tidal Marsh
Tidal salt marshes form a grassy fringe near river mouths, bays, and along coastlines protected from the open ocean. Ocean tides fill the marsh with salty water and cause the water level to rise and fall twice a day. The marsh is deeper at high tide and shallower at low tide. Hunter’s Point South Park contains 1.5 acres of constructed tidal marsh which provide habitat for many native species of flora and fauna, including migratory birds and keystone species such as ribbed mussels. They also shield land from storm surge and sea level rise. By providing a buffer for tides, they prevent shoreline erosion and absorb excess nutrients that would lower oxygen levels in the sea and harm wildlife.
East River/NC as estuary system Dock or Overlook
Did you know that the East River isn’t actually a river? It’s actually a tidal estuary that connects New York Harbor which is the bay that starts south of Manhattan, to the Long Island Sound. This means that because of the tides the current sometimes flows north, or upriver and sometimes flows south, or downriver, and sometimes is slack, or calm. You can see the difference in the flood, or northern, high water level, and ebb, or southern, low water level, currents by looking at the water lines along the rip rap.
Because of these often strong currents, human-powered boating can be very difficult to navigate and must be timed around slack tides, especially for beginners. That’s why trips from our Queens Landing Boathouse only go out with trained trip leaders who know how to time trips around these currents and are trained to rescue anyone who gets stuck and is unable to paddle back on their own.
Organic pollution, oxygen levels, algae
You may have noticed that sometimes the creek changes color, turning green, yellow, or even reddish, especially after rain, or you might have seen our large fish tank turn green when it was still in the front window. Because of New York City’s combined sewage system, raw sewage is frequently dumped into the creek, causing an excess of organic materials that algae and plankton can feed on. When this happens, they will bloom, meaning a large number of these microorganisms have multiplied in a location. As these microorganisms die, they are eaten by bacteria that also consume oxygen, leading to oxygen levels in the creek that can be too low to support fish or invertebrates, causing them to die. Bacteria from raw sewage can also lower oxygen levels.
The color of the bloom is determined by the specific species of microorganism present. Groups like the Newtown Creek Alliance are working to protect the creek from these blooms by limiting runoff and adding plants that can help absorb the excess nutrients. You can also help by limiting water use during rain storms.
>> Urban Structures: Climate resilience <<
Urban heat island
One of the most obvious effects of climate change on our neighborhood is the increase in the number of heatwaves we’ve seen in recent years. You may have noticed that time spent in the parks feels cooler than among the concrete and asphalt elsewhere in the neighborhood, and it’s not just because of the breeze off the river.
Unlike buildings and other dark hardscapes that absorb heat and raise the surrounding temperature, the trees and plants in parks help reflect light, keeping the surrounding areas cooler. Shade from trees keep pavement from getting as hot, and plants also absorb heat through a process called evapotranspiration. This process is similar to sweating where water evaporates from leaves, cooling the plants and absorbing energy from the sun. The increase in heat caused by built surfaces is called the urban heat island effect, and it’s one of the key reasons parks are so important to communities.
During the last heatwave we measured the temperature in the sun on the sidewalk on Vernon Blvd and in the sun on the grass near the marsh in Hunter’s Point South Park, and found the park was 7° cooler.
Bioswales
One of the most striking features of Hunter’s Point South Park are the garden beds that separate it from the street. Did you know that they help protect our neighborhood during heavy rain storms? These gardens are bioswales, or rain gardens, which absorb rainwater during heavy storms and help filter it before it reaches our rivers and creeks. This helps prevent flooding, and also reduces pollution in our waterways. NYC’s sewers are 80 years old, and not designed for the number of people in the city or the heavy rain events we’re getting with climate change. Every time it rains, storm drains empty into the sewage system, and raw sewage is dumped into our waterways. Capturing rainwater in bioswales and other features that reduce impermeable surfaces, helps limit the amount of sewage in the water. And the flowers are lovely.
Rip rap
One thing that sets our waterfront apart from many others in NYC is the use of riprap instead of bulkheads along the waterfront. Rip rap, or the rocks that line the river, serves several purposes for our parks. It helps protect against erosion of the riverbank from the tides and storm surges, helps create habitats for invertebrates and small fish. More importantly, unlike bulkheads, and concrete walls that you can see across from us lining the Manhattan shoreline, riprap helps reduce the impact of storm surges like we saw during Hurricane Sandy. Because of its uneven surface, riprap absorbs and dissipates the energy from waves, reducing their severity.
CSOs
One of our biggest challenges with climate change is the increase in heavy rains, but even with more mild rains our rivers and creeks face pollution challenges. NYC has a Combined Sewer System which collects stormwater runoff, domestic sewage, and industrial wastewater in the same pipes. During rain or melting events, the sewer system’s capacity is often exceeded and the excess water is discharged directly into rivers and creeks.
There are two locations in Hunter’s Point South Park and 5 in Gantry Plaza State Park where the sewage system releases wastewater into the East River, polluting the water. There are also 22 CSOs dumping into Newtown Creek.
Bioswales and other green infrastructure help mitigate this CSO issue by collecting and filtering stormwater and diverting it from the sewer system, limiting the amount of raw sewage in our waterways.
Gabion walls
One of the more interesting features of the bioswales in Hunter’s Point South Park are that they contain a gabion or “gabion wall” which runs its length. It is a long wire cage filled with rocks of varying size which helps filter sediment and heavy metals from the water retained in the bioswale and helps the water slowly infiltrate into the soil. Because our parks are boarded by a river and a number of roadways, it’s particularly important to limit the amount of pollution that reaches the waterways.
Wetlands map vs Sandy inundation zones
One of the biggest threats facing our neighborhood is the potential for major flooding during storm surges. In addition to being a low-elevation area, much of the waterfront was built over wetlands.
Until the mid 19th Century, most of the neighborhood west of Vernon was marshland, as you can see in this overlay of the neighborhood in 1609 versus how it looks now. In fact, if you look at a map of historic wetlands in New York and New Jersey and compare those to a map of Sandy inundation zones, you’ll see they line up extremely well.
We now know that wetlands are essential not just for biodiversity and water quality management, but also for resilience. While we’re used to thinking of ongoing environmental impacts from the industrial era in terms of pollution, recognizing the role of loss of habitat and working to restore wetlands areas like was done in Hunter’s Point South Park is an important part of designing for climate change.
Oval reservoir
The turf athletic field in Hunter’s Point South Park is a prime example of efficiency and practicality in a design feature that serves two very different, but important purposes. The field is designed to be a multi-use play surface, where on a sunny day you will see people of all ages running around, playing frisbee, soccer, football, and more. You can attend many of our programs in this space.
In addition, it is also a feature which can hold up to 600,000 gallons of water, protecting the neighborhood from potential storm surge. While we focus a lot on green infrastructure, using gray infrastructure like reservoirs that serve multiple purposes are an excellent way to increase an area’s resiliency.
Waterfront access Dock
New York is a series of islands, a city defined by its waterways, but most New Yorkers have no meaningful access to them.
Because of the use of waterfronts for industry, and the pollution related to those uses, and decisions about transportation and highways, getting to the water, much less into it, has been a challenge for decades. Many efforts have been made in recent years to give people a way to connect to rivers and creeks, but industrial and warehouse sites still dominate many banks.
Giving people more access to our waterways for recreational use encourages conservation efforts and improves individuals’ wellbeing, which was one of our primary motivations for opening the Queens Landing Boathouse and Environmental Center.
Berms Southern Lawn
Berms are compacted hill-like structures that contain dense sediment materials that decrease water velocity, control flow rates, and absorb excess water in the event of a flood.
These hill-like structures are particularly present in Hunter’s Point South Park Phase II where their primary purpose is to protect the adjacent buildings from possible storm surge of the East River. The varying elevations found in this region of the park are designed so that a 100-year storm would cause no damage to the new buildings in Hunter’s Point South.
The berms rely on the grasses planted along them to prevent erosion during storms, which is one of the reasons our volunteer groups’ work removing weeds and invasive species is so important.
Permeable vs impermeable Old Pier
Many of the resilient features of our parks focus on increasing the amount of permeable surfaces. Permeable surfaces are those like planted areas that can absorb rain water, compared to impermeable surfaces like most roadways, buildings, and sidewalks that push any water that falls on them onto adjacent surfaces or into stormwater drains.
Because of NYC’s combined sewage system, stormwater dumps into the sewage system and then raw sewage is dumped into our waterways. The primary way the parks combat this is through extensive planting areas and water capturing features like bioswales.
But in Hunter’s Point South Park the sidewalks are also designed using permeable concrete so that rainwater can sink through the hardscape rather than being redirected.
>> Wildlife: Animals <<
Ailanthus and Lantern flies
By now you’re familiar with the invasive spotted lantern fly, the brightly colored insects that we’ve all been stomping on for the last few years. They are extremely destructive to many plants, including those in our parks. Their favorite food source, and preferred place to lay their eggs, is the ailanthus or tree of heaven, another invasive species. This tree grows incredibly quickly and is considered one of the worst invasive species of plants in both Europe and North America. It’s incredibly hardy and able to grow in areas where few other trees can, which is why it serves as the main metaphor for resilience in the popular story, A Tree Grows in Brooklyn. It can send up clones alongr its roots, a process known as suckering, and frequently resprouts after being cut, making it very hard to remove. This tree is very tolerant of drought and sun, and it produces a chemical that inhibits the growth of other plants to reduce competition. There are several ailanthus growing on the lots near the park, which we’re watching carefully for lanternfly eggs. If you have these near you, make sure to either remove the eggs or report them to help limit the number of lanternflies we’ll see next year.
Spotted Lanternfly Predators
We’ve seen a lot of people doing their part to combat the spotted lanternflies since the adults emerged this summer, but did you know some of our park animals are helping too? One of the reasons the spotted lanternfly is so destructive is that it has few native predators, but mantises and gray catbirds will both happily catch and eat them. We have two species of praying mantis in our park, and they like the longer grasses, where they blend in well and can hunt other bugs. We often find them during our weeding groups and put them back into the grass after snapping a few photos. Grey catbirds, which are named for their cat-like calls, often like to sing from within trees and bushes, making them hard to spot. We’ve seen them often in the trees near the Luminescence sculpture, and in the thicker bushes near the great lawn in Gantry Plaza State Park.
Milkweed and monarchs
Monarch butterflies are the poster child for pollinator conservation. The beautiful orange and black insects spread from the eastern US and Canada all the way to their migratory sites in Mexico, which means their conservation requires an international approach. In 1996, there were an estimated 1 billion monarchs in North America, but by 2016 that number had fallen to only about 100 million individuals. Climate change, loss of habitat, and pesticide use are all contributing to the decline, but for the last 20 years organizations and individuals have been working to help restore their numbers. Our parks are helping by providing key species for the monarchs life cycle including the milkweed planted here in Gantry Plaza State Park. Monarch caterpillars exclusively eat milkweed, so these odd looking plants are needed for them to thrive. The adult butterflies eat pollen from the many other flowers in our parks, and from the pollinator garden we created with the Newtown Creek Alliance on 48th Ave.
Skillet fish, Sea Bass, Killifish
Newtown Creek used to be the most polluted waterway in the country, but thanks to the environmental efforts of groups like the Newtown Creek Alliance, it now supports a thriving ecosystem despite the ongoing challenges from industrial pollution and the dumping of sewage in the creek. At the Queens Landing Boathouse and Environmental Center, we feature some of the creek animals in our tanks. The skilletfish is a small, frying pan-shaped fish often found clinging to rocks and oyster shells with its suction disk. They grow up to about 3 inches in length and have a brown speckled color that allows them to blend in with oysters and bottom sediments. Black sea bass are striking fish known for their dark color and iridescent blue spots. Native to the Atlantic Ocean, these fish are bottom dwellers that thrive in rocky reefs and coastal waters. They are very adaptable and have the unique ability to change color and sex during their lifetime.
There are several species of killifish found throughout NY Harbor and its streams or “kills.” They are small and feed primarily on insect larvae, aquatic crustaceans and worms. They have a high tolerance for pollution, temperature, salinity, and dissolved oxygen levels, as is common in Newtown Creek.
Grass shrimp & mud crab
Newtown Creek used to be the most polluted waterway in the country, but thanks to the environmental efforts of groups like the Newtown Creek Alliance, it now supports a thriving ecosystem despite the ongoing challenges from industrial pollution and the dumping of sewage in the creek. At the Queens Landing Boathouse and Environmental Center, we feature some of the creek animals in our tanks. Grass Shrimp are transparent in color, these small shrimp live in shallow waters and can commonly be seen in summer months. Pregnant females carry eggs in a pouch that is visible through their body. The Atlantic mud crab is a small dark brown crab found on muddy bottoms, hiding under stones and shells or among sponges and weeds. Ours likes to hide under rocks or shells in the tank. It cracks the shells of clams and oysters with its strong claws.
Local birds – cormorants
Double crested cormorants are one of the most distinctive sea birds around the parks. They are large, long-necked, black birds with a bare patch of orange skin on their faces. They are often found hunting in the east river and newtown creek, or perched on a pier or near the water with their wings spread to let them dry. They can dive up to 24ft deep and can stay under water for over a minute when hunting fish. Many of them nest on U. Thant island, the small island behind us that was made during the construction of the Steinway tunnel.
Oysters & other filter feeders
While fully restoring NYC’s rivers and creeks requires a lot of investment and the removal or capping of contamination, several animals are making a big impact on making our waters cleaner. Bivalves like oysters and ribbed muscles were once abundant in the waterways around NY Harbor before overharvesting and pollution destroyed the local populations. Ribbed muscles help secure plant roots in salt marshes and are extremely hardy and good at thriving in man-made structures like those found along Newtown Creek.
Organizations like the billion oyster project are working to restore these key species to our waterways. Billion Oyster Project has added oysters to the Harlem and East Rivers, including in Gantry Plaza State Park, which has improved water quality significantly.
Oysters can filter 50 gallons of water a day, and the reefs they form provide ecosystems for other organisms. Because Newtown creek is a superfund site, groups aren’t allowed to directly add oysters to the waters, but the Newtown Creek Alliance is adding man-made structures that encourage oysters to naturally attach and stay in the creek.
>> Wildlife: Plants <<
Pollinator gardens
In 2020, we partnered with the Newtown Creek Alliance to create two pollinator gardens on the medians on 48th Ave near Center Blvd. Over 4 days, we planted over 1,100 plants to establish the gardens, and the following year added another 400 plants. We continue to hold volunteer events in the gardens with NCA multiple times a year to support the plants, insects, and birds that depend on them.
There are many benefits to this type of garden, they create habitats for ecologically valuable pollinators, like butterflies, moths, bees, and small birds. They also provide important ecosystem services including infiltration and filtration of stormwater, carbon storage, and nutrient recycling. Because they are planted with native plants, they don’t require additional irrigation and require less maintenance than non-native planting beds.
Rosa rugosa
The Rosa Rugosas in the parks have finished blooming and started producing their fruit. These naturalized species, which is also known as the beach rose, is very salt tolerant, which is why they do so well lining our wetlands and the bank of the East River, which is slightly salty from the Atlantic tides. While their flowers mostly stopped blooming during the heat wave, they’re producing their bright red-orange fruit, rose hips. Rose hips are known in medicine for their anti-inflammatory purposes. Rosa Rugosa love full sun which is why we’ve planted them along our park paths, and their tolerance for salt spray helps them survive flooding and protect against erosion when they border the river.
Pitch pine and fire pine cones
Pitch pines, which are the pine trees that give the pine barrens their name, are known for their ability to grow in difficult conditions, including sandy and acidic soil. These trees are native to the eastern US, and were used by indigenous groups including the Iroquois, Shinnecock, and Cherokee for medicinal treatment of burns, cuts, and boils, and to build canoes. Pitch pines are also incredibly resilient to fire, being able to regrow after forest fires and producing some pine cones that only open after a fire has loosened the resin holding the cone closed, protecting the seeds from being burned. Here’s an example of a normal pitch pine cone and one closed until burned. The Lenape used controlled burning in the pine barrens to make them better for hunting, which is why the pitch pine remains the dominant species there instead of being replaced by other trees. Because they are so resilient and able to thrive in sandy and slightly salty soil like we have along the river, they are planted in several areas in Hunter’s Point South Park.
Aromatic sumac
One of our park’s most successful native plants is Aromatic Sumac, or rhus aromatica, one of two sumac species we have in the park. Aromatic sumac, also known as fragrant sumac, lemon sumac, or polecat bush, produces flowers in the spring that nurture butterflies and other early pollinators. It gets its name from its leaves, which produce a lovely lemon scent when crushed. Since it can thrive in even dry summers and turns red in the fall, it helps the park look beautiful year-round, and since its along many pathways and bioswales throughout the park, its roots play a role in filtering runoff and rainwater. It’s also one of our most hardy plants, showing no signs of struggling from the drought, flooding, or extreme heat we’ve experienced in the last few years.
Sumac trees
Staghorn Sumac is named for the forking pattern of its branches which resemble antlers. This breed of sumac can be grown as a tree or shrub, and play a vital role in preventing erosion along the berms in Hunter’s Point South Park, with both the more classical smooth leaved and “tiger eyed” cultivars helping protect the soil.
The sumac grows by spreading its roots through rhizomes underground, creating colonies that shoot out new growth. Because sumac is hardy and highly drought resistant, it helps protect against soil erosion which is why it is planted in several parts of the park on hillsides similarly to the marsh grasses. The sumac in our park has happily spread from where it was initially planted, increasing the areas of the berms that are protected.
Rose mallow
One of the most distinctive and beautiful flowers in our parks is the rose mallow, or swamp hibiscus, which grows throughout the bioswales in Hunters Point South Park. These plants with large pink and white flowers are native to wetlands in the eastern US, and thrive in damp soil. They grow quickly, with broad leaves that helps them outcompete the weeds that can harm other plants in the park. Their flowers help feed native pollinators including bees and butterflies. Since they thrive in wet soil and direct sunlight they help the bioswale absorb and filter rainwater during heat waves, which is why they’re still so beautiful despite the hot, wet summer we’re having. In most of the parks we’ve prioritized functional native plants over ornamentals, but we’re lucky with the rose mallow that we get beautiful flowers that help make our neighborhood more resilient.
Beach plums
The Beach Plum is a popular shrub grown along coastlines as their tolerance for sandy soil and salt resistant nature is perfect to help counter erosion and flooding, especially along beaches in the east coast. Their delicious fruit is popular to make into dessert and jellies in coastal towns, and is an important part of the diet of our local and migratory birds.
We generally encourage you to avoid eating fruits and vegetables that are grown directly in the soil in NYC because of the dangers of soil contamination, so we can’t recommend cooking with these plums, but eating one as you walk through the park is safe.
Cone Flowers
Cone Flowers are better known by their medicinal name, echinacea, are a beloved flower for local pollinators and herbalists. The beautiful native perennials are drought resistant, humidity resistant and native to our area, which we love for our park’s ecosystem. These flowers are hard to miss as you can find them all over the parks, and can stand as tall as 4 feet, and are located throughout the bioswales in the park.
Grasses – Southern Lawn
Grass is so common in parks that we don’t even really think about it when listing park plants. However, several species of grasses in our parks serve to promote resiliency and environmental protection.
The park grasses include bluestem, spartina, panicum, and dwarf fountain grass. Tall grasses like these serve several different purposes that help our park’s environment. They capture a large amount of carbon, since their root systems often extend much more broadly than the visible parts of the plant.
Because of these extensive root systems, grasses also protect against erosion much better than the temporary invasive weeds that compete with them.
The grasses’ roots hold on to soil even during heavy rain and floods, and also help filter out excess nutrients before they reach the river and creek.
In areas where the grasses have been outcompeted by invasive weeds, we see serious signs of erosion each winter.
Catmint & resilience to nature and use – Midpark Path
One of the plants that you’ll see a lot of in our parks is catmint, or nepeta. This perennial, which is related to catnip, is naturalized in the US and is known for thriving on neglect.
Once it’s established, it is incredibly drought tolerant, can handle full sun well, and can survive being peed on by dogs without being damaged or destroyed.
The purple flowers come out in late spring and last through the fall, meaning it feeds pollinators for almost our whole growing season.
Because it is so hardy and tolerant of dogs, we use it to line many of the bioswales along pathways in Hunter’s Point South Park.
Honey Locust – Dog Park Area
Honey Locusts are very common in our neighborhood and are native to New York. These trees are part of the pea and bean family and produce distinctive seed pods in the fall.
We plant the thornless variety in our parks, but wild honey locusts produce large thorns that evolved to protect the trees from wooly mammoths and other megafauna that were found in New York during the last ice age.
These trees are drought tolerant once established, and are able to deal well with salt spray from roads in winter, compacted soil, and pollution, which is why they are so commonly planted in cities. Unlike acorns, their seed pods pose no danger to dogs that chew on them, which is why we purchased 3 honey locusts in 2022 to plant in the dog park inno Hunter’s Point South Park’s to replace oaks that had died.
Willows – Gantry Peninsula
One of the most distinctive trees in Gantry Plaza State Park and Hunter’s Point South Park are the willows. These lovely trees were so admired that they were spread along the silk road from their native range in eastern China to the middle east and then into Europe and eventually the US.
Willows grow very quickly and love areas with a lot of water, which is why they’re so commonly seen along rivers and ponds.
Their leaves come in very early in the spring and last late into the fall, and they support a number of pollinators. These beautiful trees also help prevent erosion while beautifying our parks and providing much-needed shade thanks to their rapid growth.
Sweet gums and willow oaks – Midpark Bike Lane
Sweet gum trees and willow oaks line the walkways of Hunter’s Point South Park. Sweet gums are native to the eastern US south through parts of Mexico and central America. The trees are named for their aromatic, sweetish smelling resin, which was used by indigenous groups and Europeans for medicinal purposes because of its anti-inflammatory, antioxidant, and antimicrobial properties, to make chewing gum, and for the pleasant smell of the resin when burned. Sweet gum leaves turn bright red, yellow, or orange in the fall, and their distinctive spikey fruits hold seeds that are food for finches and other small birds.
Along much of the bike lane in Hunter’s Point South Park there are willow oaks. These trees in the red oak family are popular park trees because they give off great shade and tolerate urban pollution well. They also are important for the larger ecosystem, hosting the larva of many species of moths and butterflies that will go on to pollinate our parks.
Seeds – Thistle & Catmint
Plants spread in our parks through a wide variety of methods, which makes picking the right plants for each area (and controlling weeds) important. We’ll start with the most well known method, seeds.
The most common method for plants to move from one area to another is through seeds. For some of the invasive weeds in the park, like thistle, they can go to seed multiple times a summer and spread through the wind, meaning our volunteer groups might be pulling thistles with flowers every 5 or 6 weeks in the same area. Others like white mulberries have seeds that primarily spread after their fruit are eaten by birds, who then deposit the seeds in their [waste? Poop? Whichever you prefer to say], meaning that even if we managed to remove all the white mulberry in the park we’d still see new trees introduced from nearby areas. Seed propagation is also used by some of the beneficial perennials in the parks – catmint and some other flowers self seed, so they can expand after being planted to fill in gaps between plants.
Cuttings – Near Willow
Plants spread in our parks through a wide variety of methods, which makes picking the right plants for each area (and controlling weeds) important. One of the most common methods of reproducing plants and trees from greenhouses is through cutting, though this process can also happen naturally.
Some plants grow best from cuttings, which is when a bit of an existing plant is taken, placed in water, and left to develop its own roots and leaves that can then be replanted. This is very common for a lot of plant types, but some plants like weeping willow, also do a natural version of this as a form of asexual reproduction, since all most of the cultivars that are planted are female. They drop branches that can take root when the conditions are right, which is what allowed willows to become naturalized in the us.
Bulbs
Plants spread in our parks through a wide variety of methods, which makes picking the right plants for each area (and controlling weeds) important. For the last decade, HPPC has hosted a volunteer day attended by over 200 people dedicated to bulbs.
Many plants reproduce through bulbs, though the most famous are alliums, which include onions, garlic, and the flowers with pretty purple spheres we see in the parks each spring, and flowers like daffodils and tulips. While seeds contain the embryonic form of a plant that will develop into the adult form, bulbs actually contain miniature versions of the entire mature plant, including stems, leaves, and flowers. Once the plants have grown, they will start remaking a bulb in their roots, allowing them to come back year after year if not disturbed. HPPC has planted almost 100,000 bulbs in the parks with the help of our volunteers are our annual Bulbfest, held the first Saturday in November.
Rhizomes – Sumac
Plants spread in our parks through a wide variety of methods, which makes picking the right plants for each area (and controlling weeds) important. Several of the species in our parks spread through rhizomes.
Rhizomes are underground stems, or rootstalks, that send out roots and can send up new shoots to grow what looks like a new plant, though it’s actually still a part of the original. Some plants, like staghorn sumac, can send rhizomes up to 10 feet away, which is why we sometimes find sumac shoots growing in the bioswales even though their main trees are on the other side of the walkway. While it means we have to sometimes remove sumac from other areas, this method of spreading is overall beneficial to the parks, since the trees have been expanding on the berms to provide more erosion protection. This method of plant growth can also make plants extremely resistant to attempts to remove them, though. Bindweed rhizomes can survive being cut up in the soil for up to 3 years, which makes eradicating them extremely difficult.
Native, Naturalized, Non-native
We talk a lot about native plants in the parks, so it’s helpful to understand exactly what this term means.
Native plants are those that evolved in a particular location. Because they evolved for the conditions of that location, they usually require minimal support to keep alive, and tend to need less watering and other attention once established. They also support other native species of insects, birds, and other animals that coevolved near them, meaning that the presence or absence of native plants can have a big impact on the ecosystem around them. However, some native plants can behave aggressively and be “weeds” that need to be removed.
Non-native plants are any plants that were introduced from another area. Some of these can be invasive, but many are beneficial, like the japanese spirea that thrive in marshes and help our bioswales absorb water. Others like catmint and willow have been naturalized, which means that even though they didn’t evolve in an area, they are well suited to it and capable of reproducing and spreading without human intervention and care.
We try to plant species that require minimal watering, and don’t use any chemical pesticides or fertilizers because we’re so close to the river, so most of the plants in our parks are native or naturalized.
Invasive, Weeds – Berm Path Near Creek
Weeds and invasive plants are a big part of our focus when running our community gardening groups, so it’s helpful to understand what exactly these words mean.
“Weeds” isn’t actually a biological term, but just refers to any plant that is somewhere that it isn’t wanted. In formal gardens, this often includes many native species, but when we talk about weeds we’re specifically referring to plants that have a negative impact on our parks by outcompeting other plants that are serving a specific purpose, like erosion prevention, helping the bioswales, or supporting local pollinators. The vast majority of weeds we deal with are annuals, which means they tend to die in the winter, leaving unprotected patches of soil. Some of the weeds in our parks are native species that can be beneficial in some circumstances, but also have negative effects that mean we don’t want them in the park, like pokeweed, which is poisonous and tends to spread over other plants once established.
Invasive plants are those that will spread and prevent other plants from growing in a location. Many of these, like mugwort and thistles, are used in their native ranges for medicinal purposes, but spread so rapidly in our area that they can outcompete other plants and cause them to die off because they take all available nutrients from the soil, or their roots block out other plants. Others like bindweed and other vines will grow on top of plants, blocking out the sun that plants need to thrive. We remove around 2,000 bags of invasive weeds from the parks every year with the help of our volunteers. If you’d like to get involved, you can join us Thursdays and Saturdays at 10am from May through October.
Bindweed – Southern Path Near Mouth
Vines are some of the most destructive invasive species in our parks. Field bindweed, which is related to morning glories and produces pretty white and pink flowers, grows incredibly quickly to full cover grasses, rose bushes, and other plants, blocking out the sun and suffocating their roots. Bindweed’s roots can grow up to 20 feet underground, and any root fragments left in the soil after being pulled can regrow into new plants.
The parks’ gardeners and volunteers also work to remove catchweed, which is also known as velcro weed and is especially prevalent in the spring and produces leaves and seeds that stick to everything, and virginia creeper, which is a native vine that can damage young trees.
Thistle Berm
One of the most challenging weeds for us to combat in the parks is thistle. The park has three different types of thistle we’re battling: Bull Thistle, Common Sow Thistle, and Creeping Thistle. These weeds grow pretty flowers, but spread very quickly, outcompete our native plants and grasses for space and water, and the roots suffocate the rest of the plants they surround once established. Thistles can grow very tall very quickly, and are covered with spines that make removing them difficult even with gardening gloves. Because they grow so quickly and can flower and go to seed in a matter of weeks, we find our gardening groups removing them from the same areas multiple times a summer in order to help the plants around them survive.
Mugwort in Berm Path? Anywhere really
One of the most common weeds in both our parks, and throughout the city, is Common Mugwort. This invasive plant is mostly identified by its broad leaves, which are wide, deeply divided into finger-like, wedge or spatula-shaped lobes along the central vein, and by its sage-like aroma when crushed. It has many medicinal uses in its native habitats in Europe and parts of Asia, but it outcompetes the local plants that are helping our pollinators and undermines the integrity of the park’s green infrastructure when it chokes the native grasses. Mugworts are usually introduced when a bit of root is added to soil, and they spread by rhizomes to expand rapidly once they are in a location. Since it’s extremely hard to get all roots when pulling them out of planting beds or grasses, they return multiple times each year, and left alone they can grow to 6 feet tall.