A garden oasis and cultural center overlooking the Hudson River

Plant of the Week: Nymphaea ‘Marliacea Chromatella’ (Water Lily cultivar)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

Claude Monet’s passion for painting water lilies was the direct result of the horticultural efforts of another Frenchman, Joseph Bory Latour-Marliac.

Until the late 19th century all species of hardy water lily—those that are native to temperate climates with cool winters—were resolutely white-flowered. Latour-Marliac discovered a way of hybridizing them and was able to produce a range of plants which would bloom in other colors.

His first success was ‘Marliacea Chromatella,’ a yellow-flowered cultivar (cultivated variety) which he introduced in 1887. We have this same cultivar today in our Aquatic Garden.


It can be seen blooming there over several weeks in late summer. In this next shot, it’s tucked into the left foreground of the pool, looking west.


Latour-Marliac exhibited his dazzling new water lilies at the 1889 World’s Fair in Paris, and they captured the attention of the thousands of visitors. One visitor was Claude Monet and he very soon created his own water garden and bought plants from the Latour-Marliac nursery. He spent much of the rest of his life painting them.



Above: Claude Monet, Nymphéas, 1915,  Musée Marmottan Monet, Paris. Public Domain, https://commons.wikimedia.org/w/index.php?curid=8966199.

Latour-Marliac’s nursery still operates and is located in southwest France.

Plant of the Week: Euphorbia cyathophora (Fire-on-the-Mountain)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

Fire-on-the-mountain (Euphorbia cyathophoroa) is native to much of the Americas and is a self-sowing annual. That means that although the plant will live for only one growing season, the seed it drops late in fall will germinate and grow the following spring.

Look for it along the path on the western edge of the Wild Garden. Its neatly-lobed foliage and red-hued bracts create an interesting effect for several weeks in late summer and into fall.close-up

As long as the seedlings are not weeded out by mistake—the recognition of desirable plants at a very early stage in their development is just one of the abilities required of a skilled gardener—they will make their presence known by late summer. This is exactly the time when gaps can appear in the garden after earlier-blooming plants have started to die back.

The first shot here looks south along the western edge of the Wild Garden. The second looks west out over the T. H. Everett Alpine House and its terrace. setting-south

setting-westClosely related to Euphorbia cyathophora, by the way, is the poinsettia (Euphorbia pulcherrima) of winter holiday season fame. A large shrub from western Mexico, where they can grow to ten feet or more, poinsettia specimens sold in pots seldom live long enough to achieve such a stature.


Plant of the Week: Indigofera amblyantha (Chinese, or Pink, Indigo)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

Chinese indigo (Indigofera amblyantha) is a large, slightly rangy shrub with a very long flowering season. From late spring into early fall, it produces successive spikes of delicate, rose-pink flowers.close-up

Its loose, airy habit blends perfectly with the naturalistic setting of the Wild Garden, where it stands next to a path running along the garden’s western edge. The first shot here is taken looking west towards the Hudson River, the second along the same path but looking south.setting

plantAlso called pink indigo, it is native to China, which explains its other common name.

Although closely related to “true” indigo (Indigofera tinctoria), which was the natural source of indigo for centuries, this species is not used in dye production.

The indigos are in the pea and bean family (Fabaceae) and a close look at the flowers will show the similarity with those of related plants, such as the sweet pea, the black locust tree and wisteria—it’s a large and diverse family.

Plant of the Week: Salvia sagittata (Arrow Leaf Sage)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

The angular, pointed leaves of this sage are unmistakably arrow-head shaped and it’s no surprise that both the common and botanical names refer to this characteristic. The Latin word for arrow is sagitta and Salvia sagittata translates as “the sage with arrow-shaped leaves.”


The foliage alone is interesting enough but, as can be seen in the Flower Garden this month, the plant produces flowers of an intense blue; perhaps the closest to a true blue of any bloom in the garden.


Native to high elevations in the Andes of Peru, Chile and Ecuador, it can survive chilly temperatures—but sadly not the frigid, but periodically wet, winters we experience here. Knowing this, our gardeners take cuttings from the parent plants each summer and start tiny new plants in pots. These occupy minimal space in our crowded greenhouses during the winter months but are ready by spring to be planted out in the garden, where they grow and flower again by the following summer.

The last two shots show it blooming in the foreground in the Flower Garden, looking southwest and west.



Plant of the Week: Canna ‘Intrigue’ (Canna cultivar)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

Among the wonders of the Aquatic Garden this summer is the superbly elegant Canna ‘Intrigue.’ Its long and narrow leaves are generously tinted with burgundy and provide a perfect counterpoint to the soft-orange flowers which are appearing now.the-plant-2close-up

Certain species, such as Canna glauca, are adaptable enough to grow in flooded, boggy conditions, yet will thrive in well-drained, normal soil. This trait has been passed on through hybridization to many of the cultivars we grow today. As can be seen, Canna ‘Intrigue’ is perfectly happy growing as an aquatic, yet it will be fine in a garden bed or even a container of regular potting soil.setting

Plant of the Week: Codonopsis lanceolata (Codonopsis/Bonnet Bellflower)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

The Shade Border Arbor, completed a few years ago, has given our gardeners a wonderful new structure to use as support for some interesting vines. One of them is this member of the bellflower family (Campanulaceae). Commonly called bonnet bellflower, or codonopsis—(its botanical name is Codonopsis lanceolata—it has taken a few years to get properly established and it is now producing its first flowers.setting

Looking for all the world like a tropical plant, suitable only for a greenhouse, it is actually hardy in this climate. The stems might be killed to the ground in winter, but it grows back strongly from its tough root system each spring.

The flower buds are dimpled, greenish-white puffs—which resemble barn owl faces at certain angles!—and they open to reveal purple-lined petals and a specked interior.close-up-owls-face

close-up-darkThe walls of the flower are so thin that they are translucent and the odd dapples of sunlight that filter through the surrounding trees cause them to light up like delicate lanterns. When you venture to the Shade Border, look for them behind the middle pillar in this last shot.setting-2

Native to East Asia, the bonnet bellflower is an adaptable plant which will grow in full sun or part shade.

Plant of the Week: Lilium leichtlinii (Leichtlin’s Lily)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

Leichtlin’s lily (Lilium leichtlinii) grows up to four feet high and produces masses of golden-yellow flowers. They are tinged a dark red at the base and have purple freckles on the inside of the “petals” (technically, tepals). Coupled with the purple-green of the stems, it is a very handsome lily.close-up

Named for the German botanist Max Leichtlin (1831–1910), who introduced many plants into cultivation, it comes from central Honshu, the main island of Japan.plant

July is a peak time for lilies at Wave Hill and Leichtlin’s can be seen in several places, including the Flower Garden and the Monocot Garden.setting-1

Putting NYC (Invasives) On the Map

Baruch Tauber joined Wave Hill’s Education team in late May as Forest Project Senior Crewleader, and is running the PRISM invasives monitoring initiative. Tauber holds a degree in landscape architecture. This post from the field comes as New York State’s Invasive Species Awareness Week draws to a close. 

New York City is a celebrated melting-pot of culture, ideas and identities. For centuries, New York’s harbor has welcomed immigrants from around the world. Some bring with them animals or plants that quickly established and thrived in the city’s landscape, outcompeting or even eradicating essential parts of our natural ecosystem. For this reason, some ecologists also refer to NYC as the “ground zero” for invasive species.

The city also sits on the border of multiple ecological zones. For example, Staten Island is the northernmost point for many species. Many invasives will have to pass through this region before continuing north. Similarly, the Riverdale neighborhood in the Bronx and its surrounding 900+ acres of woodlands serves as an important transition zone between the Bronx and suburbia.iMap j bar spread 0713


Here at Wave Hill, the Forest Project 2018 cohort of 22 high school students are working to restore our woodlands and learn about their ecological context. This year, for the first time, through funding help of Lower Hudson PRISM (Partnerships for Regional Invasive Species Management) students will take this work beyond Wave Hill. Working with neighborhood residents and institutions to mitigate the destructive spread of invasive species, these students are raising awareness of urban ecological systems on a neighborhood level.

An essential tool for this process is iMap Invasives, PRISM’s mobile GIS mapping technology. This app allows professionals and volunteers alike to map the spread of targeted species through an intuitive data collection interface.


Every week, Forest Project students survey a specified area looking for the presence—and absence—of an emerging or particularly threatening plant species. After using their well-honed plant ID skills to find the species, a location marker and photo is uploaded to NY State Department of Environmental Conservation (DEC) database for invasives management.iMapp 0713

As the summer progresses, survey results will vary from week to week and from species to species. Last week we canvassed the woodlands of College of Mount Saint Vincent in search of Japanese barberry, a once popular ornamental plant and a prime environment for deer ticks. On a recent field trip to Rockefeller State Park Preserve in Westchester, we saw dozens of barberry shrubs lining the path, yet in Riverdale we found none. Looking at the PRISM database map, we can see that barberry—while still spreading in rural and suburban areas—is apparently almost absent in New York City Parks. This is good news for the health of New Yorker City dwellers. Our survey results, along with the work of hundreds of volunteers throughout the region, is now in the State database and provides essential data for geo-specific pest management.

For nearly four decades, Wave Hill’s Forest Project has introduced hundreds of NYC students to the ecological roles of urban woodlands, as part of a patchwork ecosystem. Through piloting Wave Hill’s iMap Invasives initiative, they are learning how to apply their knowledge to their own neighborhood. Utilizing the DEC’s resources, they can begin to see a larger picture and how even small interventions at the neighborhood level can equal more than the sum of its parts.

Plant of the Week: Pelargonium graveolens (Rose-scented Geranium)

Charles Day is Wave Hill’s Ruth Rea Howell Senior Horticultural Interpreter.

There are many species of scented geranium, each with its own unique aroma, released whenever the foliage is lightly brushed. Besides being excellent plants for garden containers, they are grown commercially on a field scale for their aromatic oils, which are used as flavorings in foods and as fragrances for soaps and cosmetics.plant

Native to Southern Africa, and called pelargoniums by botanists, scented geraniums are distinguished from the related, cold-hardy cranesbills (Geranium spp.) by their flowers. Pelargoniums have two upper petals and three lower, usually of a different size or shape and sometimes of a slightly different color. The cranesbills usually have five, evenly-sized and uniformly-colored petals.close-up

Pelargonium graveolens is known for its remarkable rose-like scent. It is often used as one of the parent species in the hybridizing new cultivars and, although they might be very different in appearance (and scent), many geranium oils will have “Pelargonium graveolens” listed on the label. Our plant in the Herb Garden is called the “true rose-scented” geranium, indicating that it is the original species.setting

Right next to it is the peppermint-scented pelargonium (P. tomentosum) with its large, velvety leaves. Located nearby are other pelargoniums, with scents ranging from nutmeg and apple, to lemon and even coconut.

2018 Teen Internships Get underway

Barry Kogan, Wave Hill’s Senior Manager of Youth Programs, manages Wave Hill’s Forest Project, a six-week, paid summer internship for teens that works to improve the ecology of the Bronx, and the Woodland Ecology Restoration Mentorship (WERM), a 14-month program for high school students.

It is the start of a new summer at Wave Hill, and both our Woodland Ecology Research Mentorship (WERM) and Forest Project (FP) internship programs are officially underway. With a wonderful group of fresh students and a couple of exciting new initiatives, we here on the Youth Programs team are optimistic that this 2018 session will be our best yet. Out of 170 applicants, a total of 45 students were accepted into our programs in June. These are high schoolers between the ages of 15 and 18 who have a demonstrated interest in learning about forest restoration and scientific research.

This summer, 22 WERM research interns are already at work, including nine ongoing interns who are beginning to work with their mentors, and 13 new interns who are just starting their 15-month, WERM journey. IMG_1921They are pursuing a full schedule of college-level courses, restoration field work, workshops on data collection and analysis and a medley of lectures on restoration topics.

Our 22 Forest Project interns are likewise carrying out restoration work and data collection this summer. Seven of these FP interns—all high school seniors—will be taking a class on Geographic Informational Systems (GIS) at the College of Mount Saint Vincent, while the other 15 will be taking a Restoration of NYC Natural Areas course here at Wave Hill.IMG_7053IMG_7055

As the summer progresses, we will be posting blog entries that go into greater detail about all aspects of our programs, including the students’ courses and research.IMG_7061

Wave Hill as Part of a Larger Ecosystem
Our youth internship programs continue to be rooted in the authentic setting of New York City ecological restoration. The eight-acre forest on Wave Hill’s grounds—the Herbert and Hyonja Abrons Woodland—serves as the perfect setting for our students to put their restoration work into practice. Situated within Riverdale, our forest is part of a larger ecosystem in the Bronx. While our students carry out their restoration work here on Wave Hill grounds, our WERM interns conduct research projects in their second summer that enable them to explore other areas within this larger ecosystem. For example, in their second summer these Senior WERM students are working on projects with their respective mentors at The New York Botanical Garden and in Inwood Hill Park. We place a great deal of emphasis on continuing to work closely with partners across the NYC area, as well as translating our interns’ education into practice.

While Wave Hill has been a leader in urban forest restoration for over 38 years, our internship programs and curricula are constantly being updated to provide a foundation in modern scientific restoration methods. Our students learn a data collection protocol that is based on methods used by the Natural Areas Conservancy (NAC). In 2013 and 2014, the NAC conducted the first standardized assessment of 10,000 acres of forests and wetlands across the entirety of NYC. Our students carry out a similar assessment in our Wave Hill forest to draw conclusions about its natural history, as well as to assess threats and deduce how to restore and sustain the forest and its native species.

New Collaboration with PRISM
The newest exciting initiative being incorporated into our program this year is our collaboration with Partnerships for Regional Invasive Species Management (PRISM). This is an initiative to provide working data about the diversity of species present across New York State, and particularly to spread awareness about invasive plants and their effect on natural ecosystems. This summer marks the start of our PRISM pilot project. Consistent with the idea that our forest here at Wave Hill is part of a larger ecosystem, our PRISM surveys will take place in the Riverdale area. In addition to Wave Hill’s eight acres of woodlands, work will take place in Riverdale Park, Van Cortlandt Park, and a few patches of woods in the surrounding areas that are on private property, such as the College of Mount Saint Vincent campus. The goal is to have these patches of urban woodland in Riverdale be viewed and used as a connected ecosystem that is routinely explored, restored and valued by the local community. With this PRISM initiative we are helping to increase and improve restoration and invasive management in the local Riverdale area, increase the numbers of youth and adults trained in restoration and invasive monitoring skills in the Bronx, as well as increase awareness and understanding of the importance of urban forest restoration and monitoring.

Participating in PRISM is a natural fit for us here at Wave Hill because of our authentic natural NYC setting and promoting community awareness and participation in restoration. The goals of PRISM tie in perfectly with our Forest Project internship, enabling us to engage our local high school students, college students and community members in the restoration efforts. Information gathered about the presence/absence of invasive species will be entered into the iMap Invasives app—a useful tool for crowdsourcing data. This initiative will be particularly active during the NY State Invasive Species Awareness Week, taking place this summer from July 9 through July 15.

Stewardship Mapping Project Part of Gallery Exhibition this Summer
While the focus of our attention this summer is on our beloved WERM and Forest Project internship programs, there is a myriad of other related and exciting programs happening at Wave Hill this summer that are worth noting. An educational program for a group of students from Bronx Institute at Lehman College will be hosted at Wave Hill on Fridays. These students will develop their knowledge of urban forests and learn how to compare and assess attributes of healthy forests through a course similar to our Restoration of NYC Natural Areas course. In Wave Hill’s Glyndor Gallery, the exhibition this summer, Ecological Consciousness: Artist as Instigator, will include a STEW-MAP project. STEW-MAP (Stewardship Mapping Assessment Project) is a searchable database and map of stewardship groups in New York City. This is a wonderful project highlighting the civic groups and social networks that comprise the multitudes of environmental stewards in local communities. Additionally, our Public Programs department is constantly leading exciting events and activities at Wave Hill, including local hikes that often have a restoration theme to them.

We hope you come visit beautiful and historic Wave Hill this summer, and if you take a stroll through our grounds you will most likely catch a glimpse of our WERM and Forest Project interns hard at work restoring the forest.