What’s Blooming on The Greenway this May

13, May, 2021

Written by Darrah Cole, Senior Horticulturist and Designer

We invite you to explore The Greenway by discovering what’s in bloom along the 17 acres of our organically maintained lawns and gardens! The Greenway Conservancy has a dedicated group of volunteers who walk the park and record phenological observations every week. They are helping us (and you!) find the best, most exciting and interesting plants – right now!

What is phenology? How does a bear know when it’s time to hibernate? Why do April showers bring May flowers? Plants and animals don’t have calendars or watches, but many of them take cues from the changing seasons. Phenology is the study of the timing of the biological events in plants and animals such as flowering, leaf unfolding, hibernation, insect emergence, and bird, fish, and mammal migration. Phenology is literally “the science of appearance.

May is the transition month between the bulbs and ephemerals of spring and the herbaceous perennials of the summer months. This opens the door for flowering shrubs to take center stage; the divas of the shrub world are in the height of their season. Syringa (lilac), Enkianthus, Fothergilla, Paeonia, and Viburnum are all coming to the party. The rest of the garden landscape is accessorizing with late flowering bulbs including show-stopping alliums, and quieter, star-like camassias.


Fothergilla, part of the witch hazel family is a deciduous shrub with three seasons of interest. We have two cultivars on The Greenway, Mount Airy and Blue Shadow. Spring brings beautiful, showy white flowers that are very aromatic. Walking past a fothergilla while it is blooming fills up your senses with a soft yet powerful fragrance. The flowers are attractive to our native pollinators and bloom for only two to three weeks. In fall the fothergilla foliage has a warm gradient of colors that blend nicely into the landscape. 

Enkianthus campanulatus

This unusual shrub shows off its small clustered, nodding flowers for a brief time this month. A native of Japan, where it is found in open woodland locations, the redvein enkianthus is the most common species in the landscape trade here. We have four plants in the Chinatown Viewing Garden at the very southern end of The Greenway. The small waxy leaves and upright branches become more layered over time. In sunny locations, they take on bright fall colors. While less common in New England, I have seen a few wonderful older specimens in Massachusetts; I can only hope ours get to be so long-lived. 

Syringa pubescens subsp. patula ‘Miss Kim’

Have you walked by a garden and noticed an intense sweet fragrance and wondered what it is? In mid-May, the likely answer is “Lilac”! On The Greenway, it is the “Miss Kim” Syringa, also known as the Manchurian lilac, found in five locations in the North End. There are more of these wonderfully intoxicating flowering shrubs in the middle of the park on both sides of Pearl Street and Atlantic Ave. The pale lavender to blue-pink flower clusters are smaller, and generally less intensely colored, than the popular lilacs favored throughout New England.  However, they make up for their size by packing a punch of perfume. Come to The Greenway and savor this fragrance of spring!

Rhododendron “Yaku Princess”

You can find a great selection of evergreen and deciduous azaleas blooming in the southern part of The Greenway, in Auntie Kay and Uncle Frank Chin Park, while we only have a few species of large leaf rhododendrons. Last year the Conservancy planted three ‘Yaku Princess” along the Serpentine Path. These compact growing, broadleaf evergreen rhododendrons have showy pink to blush to white blossoms, serving as a nice compliment to the nearby spectacular early-blooming tree peonies. The Yaku Princess is tucked in next to a stand of timber bamboo where  I am hopeful they will find shelter from the hot afternoon summer sun.

Looking for more phenology? The data our volunteers collect is available to you all year round through the Greenway Interactive Bloom Tracker, letting visitors locate and learn more about flowering perennials across the park. Visitors can see which Greenway flowers are typically in bloom during any time of the year, in addition to names of and details about each species. Created in partnership with WorkReduce, this interactive map graphs more than 300,000 data points and over 800 varieties of plants.

Paeonia suffructicosa