Many people think of June as the month for roses. And while it’s true for many, here at The New York Botanical Garden we generally have two peak seasons for our roses. They first come into their glory in late-May, with both the repeat flowering roses and the one-time blooming old-fashioned types exploding with color and fragrance throughout June.
The repeat blooming roses take charge for the rest of the season; some of them flowering almost continuously, while others take a four to six week hiatus before re-flowering.
We expect a lot from the roses in the Peggy Rockefeller Rose Garden so we pamper them as much as possible. They are fed multiple times during the growing season with an organic rose fertilizer in April, again in late June immediately following flower, and one more time in early August. Compost tea is used as an additional foliar feed throughout the season.
Cow manure and Epsom salts are added to soil in the spring, and compost and worm castings are added later in the season to create a fertile growing environment. A loyal troop of volunteers come to the Garden every week, and under the careful supervision of the Rose Garden Curator, Peter Kukielski, they weed, deadhead, mulch, water, and fertilize the flowers in this beautiful, historical garden.
At this time of year we are confronted with a surfeit of zucchini. The deluge begins in July increases momentum in August, and by September we’re all exhausted by this prolific vegetable.
But make no mistake: Zucchinis are great. They make the beginner gardener feel like a veteran grower. They grow as soon as you turn your back on them, maturing sometimes in just days after flowering.
An indispensable addition to any late summer garden is the hummingbird mints (Agastache). They are magnets for butterflies and hummingbirds and generally flower from July well into October.
They are heat tolerant candidates for your garden that thrive in xeric gardens with low fertility. They are in the mint family but are the well-behaved cousin that doesn’t run all over the place. With their fragrant foliage, they are deer and rabbit resistant.
We have several cultivars of Agastache in our Trial Bed Garden in the Home Gardening Center. At the end of the Trial Bed we have a tall upright cultivar called Agastache ‘Heatwave’. It reaches between 3-4 feet tall and has deliciously fragrant blue green foliage. It is covered at this time of year with raspberry colored tubular flowers. Based on its growth habit it is an ideal candidate for the middle of a border.
At the other end of the bed is a more compact hummingbird mint named Agastache ‘Acapulco Salmon & Pink™’. It is part of a popular Acapulco series that come in a variety of colors. As the name suggests it has a pretty blend of salmon and pink flowers. The shape of this hummingbird mint is reminiscent of a catmint (Nepeta) and it sprawls to form a low-growing mound that produces colorful spires of flowers.
After several spates of sizzling summer weather, many gardeners were left looking for drought tolerant alternatives to lush perennial garden plantings. One perennial that has been a stalwart of my garden has been tickseeds or coreopsis.
The odd common name of tickseed comes from the fact that people used to think the seed head looked like a tick. There are a number of species of tickseed but one of the most popular and drought tolerant species is the thread-leaf tickseed, Coreopsis verticillata.
Tickseeds are in the Asteraceae family. They tend to form 1-2 foot mounds that are covered with daisy-like flowers. They are tough customers that don’t shy away from the summer heat and have the added bonus of being deer resistant. Many cultivars flower from June through September–and sometimes into October–and are known for their flower power.
The Home Gardening Center features a number of cultivars which include a few winners in the world of coreopsis. One of my favorites is ‘Route 66’. It is an interesting alternative to your predominately yellow tickseeds. This cultivar has a red eye that bleeds into the yellow petals to produce a brilliant contrast.
Last week we looked at coral bells and covered some of the dark leaved options that are grown in this garden and easy to find on the market. This week we are going to look at some spectacular options for sunny sites.
Coral bells were traditionally thought of as shade lovers. Heuchera villosa, however, is a species that is native to southeastern U.S. It is an adaptable species that thrives in full sun to part shade, grows happily in soils ranging from slightly wet to slightly dry and is unfazed by high humidity. Understandably, it is a popular plant for southern gardens.
Hybridizers have latched on to this species and it is now part of the parentage of many successful hybrids. The French hybridizer, Thierry Delabroye has taken the world of coral bells by storm by flooding the market with a number of mouthwatering cultivars that are designed to make you either hungry or thirsty. Delabroye’s offerings include cultivars such as ‘Carmel’, ‘Brownies’, ‘Mocha’, ‘Pistache’, ‘Tiramisu’, ‘Pinot Gris’, and ‘Beaujolais’. We have used a number of these cultivars in container displays. This year we are growing ‘Brownies’ in the Trial Bed Garden in the Home Gardening Center.
The reputation of Heuchera ‘Brownies’ as an attractive and adaptable coral bell is attested to by the fact that it is flourishing in the challenging environment of New York’s High Line park. Its foliage emerges brown and then transforms into a greenish brown with a rich purple-red underside. Like the majority of Heuchera villosa hybrids it features large foliage and has a fuzzy texture. It grows over a foot tall and forms a generous two foot clump.
Daylilies start appearing in the garden in June, but the heyday for these flowers is in July. Starting from the beginning of July until the third or fourth week our Daylily Walk is awash with color. This is happening right now at the Garden!
Daylilies are generally grown for their large, trumpet shaped blossoms that jump out at you in a mixed planting, shouting ‘look at me’. And you should; they come in a vast array of shapes, colors and sizes and there are over 52,000 cultivars to choose from–many of them garden worthy companions.
When you are navigating catalogs and descriptions to find a daylily that suits your gardening style there is a basic terminology that is helpful to know. The throat is the interior of the flower, the eye zone lies just above it forming a band of color on the petals, and a halo is a faint band of color.
Some daylilies are bi-colored, some are doubles and some have a graceful recurved (curling backwards) shapes. While size, color and form are generally the attributes that gardeners assess when buying a daylily, fragrance is another factor to consider.
Snapdragons (Antirrhinum) are a terrific addition to an early season annual display but unfortunately once the heat of summer is upon us they tend to fade quite quickly. An easy solution to recapture the look of elegant vertical spires covered with blossoms is to swap them out with summer snapdragons (Angelonia).
This year in the Home Gardening Center our first Trial Bed is full of a number of varieties of summer snapdragons. There are two cultivars in this bed that I am unfamiliar with and am excited to watch them grow.
One is the cascading Angelonia ‘Carita™ Cascade Raspberry’. It reaches only 8-10 inches tall, yet spills over to form a 20 inch cascading mound. It doesn’t require any deadheading and like other summer snapdragons it is deer resistant and heat and drought tolerant. This is a candidate that would be ideal spilling over the edge of a container or at the front of a border. It would partner beautifully with a dark-leaved coral bell (Heuchera).
The other cultivar is called Angelonia ‘Serena™ Lavender Pink’. She gets 10 to 12 inches tall and just as wide. ‘Serena™ Lavender Pink’ has already filled out beautifully in the garden and formed a nice clump. The lavender pink color of the blossom will blend with just about anything. This cheerful annual looks genteel with the silvery foliage of trailing licorice plant (Helichrysum petiolare) and white fan flower (Scaevola ‘Bombay White’).
Other summer snapdragons in the Trial Bed are from the AngelFace® and AngelMist™ series. These summer snapdragons tend to be 18-24 inches tall and fill out beautifully during the course of the summer to form a substantial plant. The other year I accidentally paired the bicolored (purple and white) ‘AngelFace® Wedgewood Blue’ with an apricot nasturtium (Tropaeolum ‘Tip Top Apricot’) for a beautiful display.
While these summer snapdragons are advertised as requiring no deadheading, they do benefit from occasional deadheading which cleans them up and encourages more new growth. They will grow and flower profusely regardless. While they can handle drought they also grow well in average garden soil. This is an easy, no fuss annual that performs consistently all season long.
See a slideshow of the Home Gardening Center’s Angelonia below!
Recycled drain pipes used as planters in the Hampshire (U.K.) Garden of Pauline Thomas
By now your garden should be ablaze with color. If it’s not, and you’re finding that you have unsightly gaps in your border, don’t panic! There is still plenty of time for an easy fix: Add a container display to your garden! Don’t limit your container plantings only to the patio though, containers are also a great way to jazz-up any dull or quiet beds or borders you might have.
An attractive container display starts with a good foundation–a good looking container. Many containers these days are made of synthetic materials like poly resin and fiberglass. These materials are often transformed into believable reproductions of classic containers. Find one that suits your gardening style.
Wooden planters on the New York balcony of Devin A. Brown
If you are in the market for a rustic looking container try wood, faux wood or faux stone. If you prefer a more elegant look, then invest in terra cotta, faux terra cotta, reconstituted stone, or faux cast iron. Artistic souls will welcome the stunning array of colorful glazed pots as well as colorful lightweight synthetic substitutes that seem to be available everywhere these days. A few years ago I fell madly in love with a fiberglass reproduction of a bronze container that looked durable as well as lavish.
Colorful pots full of succlents in the Dallas patio garden of Shawn Ashmore
Maintaining appropriate moisture levels can be a challenge when gardening in containers, particularly if you like to escape for a few days during the summer. As common sense would dictate, the larger the container, the easier it is to keep it well-watered. There are many self-watering containers or contraptions on the market that you can outfit your container with. They are essentially water reservoirs that hold the water in the bottom of the container and slowly release it into the mix.
Another viable option is to add some of water retaining polymers or hydrogels to your potting mix. These polymers grab water from the soil, expand as they hydrate, hold onto the moisture, and then release it when the surrounding potting medium starts to dry. Friends of mine who plant narrow window boxes swear by them. Two brands that are easy to find are Terra Sorb® and Soil Moist™.
Whether you are placing your container in the garden or on your patio it is always advisable to raise it up onto bricks, blocks or feet to allow for good drainage. Next week we will take a look at some candidates for filling your lovely new containers.
Shade gardens call to mind stalwart plants such as hostas, ferns, and astilbes. While the Azalea Garden has an interesting array of exquisite hostas and intriguing ferns, it also includes less familiar shade-loving woodland inhabitants.
Many of these plants have interesting foliage that can add texture and color to a shade garden, and a number of them flower later in the season, providing color in the garden long after spring ephemerals and the majority of azaleas have finished their early season show. These woodlanders come in all shapes and sizes, from groundcovers to large perennials, and in a myriad of leaf colors–variegated, deeply veined, and color-tinged–and in a range of textures–fuzzy to matte and glossy.
Mukdenia rossii 'Karasuba' with Beesia deltophylla in the back
Mukdenia rossii ‘Crimson Fans’ (Karasuba) is one of two unusual plants in the Azalea Garden with foliage that gets a beautiful red tinge as the season progresses. A relative of the coral bell (Heuchera), mukdenia has been available for a few years from specialty growers and is now becoming more widely available. The main attraction of mukdenia is its spectacular fan-shaped leaves that turn red around the edges in mid-summer and continue coloring into fall. Panicles of small white flowers that resemble foam flowers rise above the plant in early spring. Mukdenia grows 12-16 inches tall and fans out 12-24 inches, like coral bells, into a nice clump. In the garden it will perform best in moist, well-drained soil in part shade. The plant pairs nicely with late flowering red astilbe such as Astilbe x arendsii ‘August Light’. Mukdenia is native to Korea and China, where it grows on slopes and in rocky ravines at the side of streams.
Beesia deltophylla, a native of China, is another plant that gets red hues as the summer progresses. Beesia makes a wonderful evergreen groundcover in a woodland garden when planted in drifts. The foliage is spectacular: The leaves are large, glossy, and heart-shaped, with deep veins that give them a rippled, puckered appearance. Beesia looks like a mutant European ginger (Asarum europaeum) on steroids (in a good way). Small white flowers appear in summer on tall stems and are fairly insignificant compared with the foliage. Beesia will grow in many soil types but does best in moist, well-drained soil in part to full shade; it grows 10-15 inches tall and spreads up to 24 inches wide.
Syneilesis aconitifolia, the shredded umbrella plant, pokes its head out of the ground in spring wearing a fuzzy white coat that disappears as it matures. The leaves open like an umbrella to reveal large, heavily dissected, lacy leaves, looking like a mayapple (Podophyllum – See “Geographic Diversity In the Azalea Garden” for more on these plants) that has passed through a paper shredder. The shredded umbrella plant will thrive in part to full shade and can tolerate relatively dry soil. It reaches 2 feet in height. Its dissected foliage looks great when paired with a broad-leaved hosta that has smooth or puckered foliage.
Cardiandra alternifolia
In the Azalea Garden are some unusual members of the hydrangea family, all recognizable by their hydrangea-like foliage. Two are perennials that reach about 18 inches tall. Cardiandra alternifolia flowers in late summer with pretty pale-pink flowers reminiscent of a lace-cap hydrangea. Deinanthe caerulea ‘Blue Wonder’ flowers in midsummer with large, nodding lavender flowers. It has the demeanor of a hellebore. Both these woodlanders like part shade and moderate to moist soil. The sub-shrub Platycrater arguta reaches 2 feet tall and 2 feet wide. It flowers in midsummer with white blooms that resemble mock orange (Philadelphus) or deutzia (Deutzia).
Dealing with Deer
Aconitum krylovii, a monkshood from Russia, is a woodland plant that is deer-resistant–or at least has the promise of being so. It can be grown in full sun to full shade and matures to a height of 2 feet. Its deep-green, deeply veined, maple-like foliage is attractive even when the plant is not in bloom. White to pale-yellow flowers tinged with green open mid to late summer.
Leucosceptrum stelipillum 'Ogon'
Both deer and rabbits tend to avoid members of the mint family and so may also pass up Leucosceptrum japonicum ‘Variegatum’ and Leucosceptrum stelipillum ‘Ogon’, Japanese shrub mints. The ‘Variegatum’ has brilliant chartreuse-and-green variegated foliage that brightens up any shade garden. ‘Ogon’ has yellow-green foliage that is equally as impressive. Both produce pale-mauve flowers late in the season, September to October, and reach 2-3 feet tall.
Trachystemon orientalis
Rabdosia longituba, trumpet spurflower, also in the mint family, looks similar to many late season ornamental salvias. This relative has an open and airy vase-shaped habit. It grows to 3-4 feet tall with long sprays of tubular lavender flowers that appear from October into November. It tolerates dry soils, does best in part shade, and pairs nicely with Japanese anemone (Anemone japonica).
The Azalea Garden has many other interesting exotic woodland plants to explore. Creamy-yellow flowered Salvia koyame blooms from September to frost while the penstemon-like purple-pink blooms of the Chelonopsis yagiharana begin in August and last into October. For early season color try the elegant Asian twinleaf (Jeffersonia dubia), with its lavender cup-shaped flowers and lobed, red-edged foliage, or the tough, weed-smothering Trachystemon orientalis, with its borage-blue spring flowers and large heart-shaped leaves.
As you stroll through the Azalea Garden you will see a large number of North American native species and their closely related Asian cousins. Many of these plants share a genus, but have different species names. For example, the garden contains many interesting Asian Arisaemacommonly known as Jack-in-the-pulpits.
In botanical nomenclature, plants are identified by a two-part, or binomial, name. A plant’s genus denotes that it belongs to one group, while the species name marks it as a member of a sub-group of the genus. There are many Arisaema in the world, yet Arisaema triphyllum refers solely to a specific Jack-in-the-pulpit, one of North America’s native Arisaema.
Why are there so many closely related species on two continents separated by a large ocean? Many of these Asian/North American counterparts come from a common genetic pool. It is possible to imagine that over time seeds have been dispersed by glaciers, wind, birds, or other animals. While this certainly has occurred it would be more likely to have happened on a contiguous landmass.
The most compelling theory for why these closely related floras are found on the opposite sides of an ocean comes from the scientific theory of continental drift, the process by which the continents have moved apart over millions of years. About 250 million to 65 million years ago, during the Mesozoic era, the landmass Pangaea began to split apart; the northern part of the supercontinent broke off into Laurasia (North America and Eurasia). As Asia and North America drifted away from each other, the plants that had been one genus began to evolve. Time, combined with changes in climate, and range fragmentation helped these once related plants to diversify and evolve into new species. Why are there so many Asian Arisaema compared with only two Arisaema native to North America? During the last ice age, parts of eastern Asia remained ice-free. This resulted in a greater diversity in the flora there.
How do botanists know that these plants are closely related? Just looking at the plants can be deceptive, so they also collect evidence from the fossil record and analyze the plants’ genes in order to determine relationships.
In this video Kristen Schleiter, Curator of Outdoor Gardens and Woody Plants, discusses many of the Azalea Garden’s geographically diverse perennials.
Many people think of June as the month for roses. And while it’s true for many, here at The New York Botanical Garden we generally have two peak seasons for our roses. They first come into their glory in late-May, with both the repeat flowering roses and the one-time blooming old-fashioned types exploding with color and fragrance throughout June.
