A Reblooming Hydrangea macrophylla Selected by Michael Dirr himself

WorryFree® Rock-n-Roll™ Hydrangea

Hydrangea macrophylla 'COF HM3' PP32584

Practically everyone loves big-leaf hydrangeas - its the look of the Hamptons and Nantucket - billowy romantic long-lasting blooms. And the most desirable cultivars are those that rebloom throughout the season. Many of the early re-bloomers were disappointing, because they only produced a small number of flowers the second time around. And a lot of the older varieties of blue hydrangeas bloom only once and grow too large for small spaces and can flop under the weight of their blooms.

Rock-n-Roll Hydrangea can potentially take the worry out of blue hydrangea planting. Selected by Dr. Michael Dirr, this hydrangea is a heavy blooming sport of Endless Summer® Twist-n-Shout®. It carries its bountiful blooms above sturdy stems and lush green foliage. The flowers are a mix of deep pink, purple, and blue and are re-blooming. It is exceedingly hardy and blooms profusely on old and new wood, providing a full season of color from June to October.

• Part shade

• Hardy to Zone 4

• Height 3 - 5 ft

• Spread 3 - 5 ft

Crimson Barberry Is Back!

The burgundy-foliage varieties of Japanese barberry (Berberis thunbergii) had long been a staple of landscape design in places with heavy deer pressure. The dwarf varieties, in particular, were valuable additions to designs, providing both structure and a beautiful deep burgundy-eggplant color. The perfect foil to Hakenochloa 'All Gold' or dwarf blue spruce.

Until it was recognized as an invasive plant in NYS and its propagation and sale were regulated. And we couldn't plant it in good conscience anymore, anyway, because what landscape designer wants to intentionally introduce an invasive into the environment.

So we limped along, using burgundy-leafed Heuchera varieties or dwarf burgundy-leafed forms of Weigela or maybe burgundy-leafed cultivars of sedum as substitutes, realizing that they didn't really serve the same function in the design as crimson barberry had.

Sigh.

But now, there's a NON-INVASIVE BARBERRY!

WorryFree® Crimson Cutie® Barberry

Berberis thunbergii 'UCONNBTCP4N' PP30095

It is a product of a planned breeding program conducted in Storrs, Conn. The new barberry plant originated from Berberis thunbergii ‘Crimson Pygmy’ (synonym Berberis thunbergii ‘Atropurpurea Nana’) through the use of the mitotic inhibitor colchicine to create an autotetraploid form of the plant. No paternal plant is involved in the creation of ‘UCONNBTCP4N’. Berberis thunbergii ‘Crimson Pygmy’ is not patented and has been used in the nursery industry since 1942. The development of this cultivar included Federal funding.

An autotetraploid is an individual or strain whose chromosome complement consists of four copies of a single genome due to doubling of an ancestral chromosome complement - in this case induced by a mitotic inhibitor. In an autotetraploid, with every chromosome represented four times, normal chromosome pairing at meiosis can be difficult, and can lead to reduced fertility (though this is not always the case).

From the Plant Patent information:

Publication Date: Feb 1, 2018

Patent Grant number: PP30095

Inventor: Mark Brand (Farmington, CT)

Unique characteristics of the new Barberry plant:

• dense habit growing to 45-60 cm (18 - 24 in) tall by 90-105 cm (36 - 42 in) wide in 10 years

• purple-red spring and summer foliage

• foliage thick and slightly leathery, held on stout stems

• fall foliage color is purple-red-orange

• small yellow and red flowers held in clusters of 3 to 6 flowers, in late April-early May

• fruit is red, ripening in October

• cold hardy in winter to at least −26° C (-15 F)

• seed production is 0.2% that of standard, diploid Berberis thunbergii ‘Crimson Pygmy’, so it is essentially seed sterile

• tested to be resistant to black stem rust by the USDA Cereal Diseases Laboratory in St. Paul, Minn.

Plants of the new Barberry differ primarily from plants of Berberis thunbergii ‘Crimson Pygmy’ in that Berberis thunbergii ‘UCONNBTCP4N’ is essentially sterile, while same age ‘Crimson Pygmy’ plants produce over 8,000 seeds per plant per year. In addition, Berberis thunbergii ‘UCONNBTCP4N’ grows approximately 10% larger than ‘Crimson Pygmy’ and has stouter stems and thicker, more leathery foliage.

This is how the plant is described on the "Worryfree" website:

Crimson Cutie® represents the first in a series of non-invasive Japanese barberries bred and tested by the University of Connecticut. Living up to its WorryFree® collection name, Crimson Cutie® will not produce nuisance seedlings or spread to unwanted areas. Approved for sale in the states of New York and Pennsylvania. This replacement for Crimson Pygmy is excellent as an accent or foundation plant in addition to low hedge and border uses. Definitely not a favorite of deer!

Yippee - we can use Crimson Barberry again!

Some more new perennials that I'd like to try, and why

I said I gave up on writing about new plants, but that proves to have been an emotional outburst. There are always new plants, and its a good idea to look through the lists and the marketing materials and see if there are some that could really work for my design practice. Below are a few more perennials that are new for 2022 - or at least newly on my radar - including information from their Plant Patent for some of them.

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Amsonia hybrid ‘String Theory’ Patent number: PP34419

Date of Patent: July 12, 2022

Assignee: Walters Gardens, Inc.

Inventor: Hans A Hansen

From the Plant Patent:

A new and distinct Amsonia plant named ‘String Theory’ is characterized by winter-hardy, compact, densely-stemmed, clean habit with linear, dark-green foliage that goes dormant in the winter; single, light periwinkle-blue, star-shaped flowers on medium height scapes flowering above the foliage beginning about early-May and effective for about four weeks. T

The most similar Blue Star cultivars known to the inventor are: ‘Blue Ice’ (not patented), ‘Starstruck’ U.S. Plant Pat. No. 32,246 and ‘Storm Cloud’ (not patented).

Amsonia hubrichtii, commonly called “bluestar,” is a native perennial with blue spring flowers and showy fine-textured foliage that turns gold in fall. The main criticism is that some people think it gets a little tall and floppy with its three-foot height. ‘String Theory, is a compact version that knocks a foot off of this plant’s usual height.

“It’s more compact than the species, plus the leaves don’t turn chlorotic (yellowish) in summer,” says Chris Ruger, a grower for the wholesale Quality Greenhouses near Dillsburg who picks ‘String Theory’ as his favorite new perennial of 2022. The variety blooms a little later in spring than the species but still retains the periwinkle-blue flower color as well as the brilliant golden fall-foliage color.

Plants grow just under two feet tall, ideally in full sun. Amsonia is also heat tolerant and not a favorite of deer. 

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Pennisetum alopecuroides Worryfree Hush Puppy - a non-invasive Fountain grass

Pennisetum alopecuroides 'Tift PA5' PP31,027

Bred at the University of Georgia

From the Plant Patent:

Open pollinated seeds from ‘Tift PS989’ plants were irradiated with 10 K of Cobalt 60 gamma radiation to produce a first group of irradiated seeds. These seeds were planted in a field to produce 256 plants. These plants were evaluated and six were selected based on morphologically desirable genotypes with reduced seed set. Open pollinated seeds (a second group of seeds) from these six selected plants was harvested and irradiated with 10 Kr of Cobalt 60. Irradiated seeds from only one of the six selected plants survived the second radiation and were planted in a field to produce 64 plants. Irradiation of seeds usually results in chimeras or sectors on the plants for the trait of interest. Therefore, each of the sixty four plant was divided into four quadrants or sectors (a, b, c, and d) and five or more inflorescences from each quadrant were examined for seed sterility. A highly seed sterile sector a of plant number 60 was selected and asexually propagated to produce ‘Tift PA5’. ‘Tift PA5’ has been tested at Tifton, Ga.

Lower Paxton Twp. PA horticulturist David Wilson, marketing director for Overdevest Nurseries’ Garden Splendor line of plants, picked Worryfree Hush Puppy fountain grass as one of his two favorite new perennials of 2022. He likes it for two reasons : 1.) it’s sterile (meaning no unwanted seeding around), and 2.) it has unusually long-lasting flowering spikes

Wilson adds that Hush Puppy has a “nice, full, and vigorous free-flowering habit with inflorescences that last much longer than conventional varieties like ‘Hameln.’ In our trials, we’ve witnessed displays that last at least four weeks longer than other varieties.”

Hush Puppy™ Fountain Grass features long-lasting pink plumes that spray high over rounded mounds of slender foliage. Plants grow three feet tall and four feet wide, ideally in full sun. Drought-tough and deer-resistant. Hardiness Zones: 5-9

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Eupatorium purpureum 'FLOREUPRE1' Euphoria™ RubyPPAF (syn. Eutrochium purpureum 'FLOREUPRE1')

Joe Pye Weed

There are lots of varieties of Joe Pye weed now - it's hard to keep them straight sometimes. Joe Pye Weed can get a bit big for a lot of gardens, topping out at six feet or more. Even recent “dwarf” varieties often grow four feet tall and wide. But its a very valuable native plant that pollinaotrs of all kinds flock to. So having a cultivar that is even smaller than 'Little Joe' is a great addition to the landscape designer's arsenal. Plus its name is a cute and clever play on the word "Eupatorium".

'Euphoria Ruby' grows just over three feet tall, doesn’t flop, and is a heavy bloomer with magenta umbrella-shaped clusters. Bees and butterflies love it. ‘Euphoria Ruby’ will grow in both damp or dry soil, ideally in full sun.

The new cultivar originated in a controlled breeding program in Quedlinburg, Germany in 2011. The objective of the breeding program was the development of Eutrochium cultivars having a compact growth habit.

From the Plant Patent:

The new Eutrochium cultivar is the result of open-pollination. The female (seed) parent of the new cultivar is the proprietary Eutrochium purpureum breeding selection coded 4846-1, not patented, characterized by its medium cream-rose colored ray florets, dark green-colored foliage, and vigorous, upright growth habit. The male (pollen) parent of the new cultivar is unknown. The new cultivar was discovered and selected as a single flowering plant within the progeny of the above stated open-pollination in a controlled environment in Quedlinburg, Germany.

The following characteristics of the new cultivar have been repeatedly observed and can be used to distinguish ‘FLOREUPRE1’ as a new and distinct cultivar of Eutrochium plant:

 1. Medium red-purple colored inflorescences

 2. Medium green-colored foliage

 3. Low growth vigor

 4. Compact-upright growth habit

Plants of the new cultivar differ from plants of the female parent primarily in having a different ray floret color, lower growth vigor, and a more compact growth habit.

Of the many commercially available Eutrochium cultivars, the most similar in comparison to the new cultivar is ‘Little Joe’, U.S. Plant Pat. No. 16,122. However, in side-by-side comparisons, plants of the new cultivar differ from plants of ‘Little Joe’ in at least the following characteristics:

 1. Plants of the new cultivar are shorter than plants of ‘Little Joe’

 2. Plants of the new cultivar have a darker purple-colored flowers than plants of ‘Little Joe’

 3. Plants of the new cultivar have larger leaves than plants of ‘Little Joe’

Anemone ‘Spring Beauty’

Anemone hybrid 'Spring Beauty Pink'

Spring Beauty Pink comes from the Netherlands and is a hybrid of Anemone sylvestris, with bubblegum pink flowers first appearing in late spring and contining throughout summer. Delicate looking, but extremely tough, its perfectly pink flowers flutter in the wind attracting all the early pollinators with its nectar. Attractive molunded foliage.

It grows 12″ tall and 15″ wide, making it compact enough for smaller gardens, and for the front of the border. Its ideal condition is dappled shade protected from the afternoon sun, yet it will also grow in full shade. It looks beautiful in woodland settings and mixed with other perennials in cottage, cutting, and pollinator gardens. It spreads by underground rhizomes and can be used as a ground cover. New plants may grow near the original plant and can be easily transplanted elsewhere.

Angela Treadwell-Palmer, founder and co-owner of Alabama-based Plants Nouveau plant introduction company, picks this as her favorite new 2022 perennial because it’s the first deep-pink, spring-blooming anemone. Treadwell-Palmer says plants might look delicate, but they’re actually “supersturdy” and seldom bothered by any bug or disease issues. And she notes that early pollinators appreciate the spring blooms.

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Nepeta grandiflora 'Summer Magic' PP27090 (Catmint)

This cultivar is not new by any means, having been on RHS Chelsea Flower show’s Short List in 2013. But its new to the US trade and is an introduction by Plants Nouveau. Their founder, Treadwell-Palmer, likes this new catmint variety because of its exceptionally long bloom time – running non-stop from May until September most years. “It blooms and blooms all summer,” she says. “The upright, deep-lavender blooms are held high above the grass-green foliage and never flop, even in the worst of storms. We admire its ability to ‘keep it fresh’ even in the heat and humidity of summer as other Nepeta varieties tend to fade.” Plants grow 15 to 18 inches tall and do best in full sun.

From the Plant Patent:

The new cultivar is a product of chance discovery by the inventor. This new variety, hereinafter referred to as ‘SUMMER MAGIC’, was discovered as a chance seedling by the inventor, Malcolm Spencer. The seed parent is believed to be Nepeta grandiflora ‘Bramdean’, unpatented, and the pollen parent undetermined. This interesting new variety was discovered in the inventor's garden during June 2010 as an individual seedling plant. The plant was discovered in West Sussex, England.

The following traits have been repeatedly observed and are determined to be the unique characteristics of ‘SUMMER MAGIC’

• 1. Compact bushy habit

 2. Improved branch structure on flower stems

 3. Improved plant sturdiness; better resistance to wind/rain damage

 4. Distinctive strong flower color

 5. Large quantity of flowers

COMPARISON TO PARENT VARIETY

‘SUMMER MAGIC’ is similar in most horticultural characteristics to the presumed seed parent variety Nepeta grandiflora ‘Bramdean’. Plants of the new cultivar ‘SUMMER MAGIC’ however, differ in the following:

 1. The new variety is shorter

 2. The new variety produces more branches.

 3. The new variety has improved resistance to weather damage—parent variety is often broken open by summer storms.

‘SUMMER MAGIC’ can be compared to the well known commercial variety Nepeta faassenii ‘Six Hills Giant’, unpatented. Plants of the new cultivar ‘SUMMER MAGIC’ are similar to plants of ‘Six Hills Giant’ in most horticultural characteristics. Plants of the new cultivar ‘SUMMER MAGIC’ however, differ in the following characteristics:

 1. The new variety is much shorter

 2. The new variety has significantly improved branching on flower stems

 3. The new variety has improved resistance to weather damage

 4. Pinching requirements and or/growth regulator use are reduced

‘SUMMER MAGIC’ can be compared to the known commercial variety Nepeta racemosa ‘Little Titch’, unpatented. Plants of the new cultivar ‘SUMMER MAGIC’ are similar to plants of ‘Little Titch’ in most horticultural characteristics. Plants of the new cultivar ‘SUMMER MAGIC’ however, differ in the following characteristics:

 1. The new variety produces longer flower spikes.

 2. The new variety produces more flowers per stem, and more flowering stems per plant.

 3. The new variety has improved resistance to weather damage

 4. The new variety produces more branches per plant.

‘SUMMER MAGIC’ can be compared to the known commercial variety Nepeta racemosa ‘Little Titch’, unpatented. Plants of the new cultivar ‘SUMMER MAGIC’ are similar to plants of ‘Little Titch’ in most horticultural characteristics. Plants of the new cultivar ‘SUMMER MAGIC’ however, differ in the following characteristics:

 1. The new variety produces longer flower spikes.

 2. The new variety produces more flowers per stem, and more flowering stems per plant.

 3. The new variety has improved resistance to weather damage

 4. The new variety produces more branches per plant.‘SUMMER MAGIC’ can be compared to the known commercial variety Nepeta racemosa ‘Little Titch’, unpatented. Plants of the new cultivar ‘SUMMER MAGIC’ are similar to plants of ‘Little Titch’ in most horticultural characteristics. Plants of the new cultivar ‘SUMMER MAGIC’ however, differ in the following characteristics:

 1. The new variety produces longer flower spikes.

 2. The new variety produces more flowers per stem, and more flowering stems per plant.

 3. The new variety has improved resistance to weather damage

 4. The new variety produces more branches per plant.

‘SUMMER MAGIC’ can be compared to the known commercial variety Nepeta racemosa ‘Little Titch’, unpatented. Plants of the new cultivar ‘SUMMER MAGIC’ are similar to plants of ‘Little Titch’ in most horticultural characteristics. Plants of the new cultivar ‘SUMMER MAGIC’ however, differ in the following characteristics:

 1. The new variety produces longer flower spikes.

 2. The new variety produces more flowers per stem, and more flowering stems per plant.

 3. The new variety has improved resistance to weather damage

 4. The new variety produces more branches per plant.

The Gardens at Wave Hill

Five Principles of Landscape Design That You Can See at Wave Hill and Use in Your Own Garden

 Sometimes the process of fine-tuning your garden or landscape can seem a daunting task.  One way to make it easier is to use public garden spaces as a resource for seeing landscape design principles put into practice.  Wave Hill in Riverdale is a public garden and cultural center which is nearby, fun, beautiful, and a source of inspiration in every season.  Originally an estate, the property was donated to the City of New York in 1960, and over several decades the gardens were restored and reinvented by the internationally acclaimed horticulturalist Marco Polo Stufano.  Wave Hill “is renowned for its intimacy of scale and its carefully cultivated serendipity: at Wave Hill, even the most seasoned gardeners can take joy in the unexpected.”  Wave Hill is one of my favorite gardens, and I’d like to share with you some of the lessons it has taught me.

Design Principle 1:  A garden should have “good bones”.  The “bones” of a garden include pathways, structures (arbors, trellises, pergolas, gazebos), statues, containers, walls, fences, ponds, fountains and all the different materials they are made from, as well as the trees and shrubs.  “Bones” also include the geometry of the space; how the elements relate to each other.  Get a map of Wave Hill from the Visitors Center.  It’s a simple, almost stylized map.  To evaluate the “bones” of your own garden, start by making a similar map of your landscape.  Look at how the walkways are situated.  Are they curved?  Do they lead to any surprises?  Where are the planting beds relative to the walkways?  Are you invited in?  At Wave Hill, you enter from the far end of the parking lot on a narrow path.  Directly in front of you in the far distance are the Palisades.  In the middle distance is a pergola.  Notice that the path does not lead directly to the pergola.  Instead, it curves to allow you to slow down and begin to meander through the garden.  

The pergola at Wave Hill in winter, with the silhouette of a hornbeam beyond and the Palisades in the far distance.

 As you walk through the garden looking at bones, notice how the perennial garden is situated to the side, surrounded by a rustic fence that sets the tone for what’s inside.  You need to walk through it to see what’s in it.  Each bed is a mini-garden in itself, and a lesson in how you can set up your own small perennial garden without being intimidated.  Each bed has its own “bones” – notice how large shrubs, small trees and even garden ornaments provide structure to each bed.  This can be best appreciated in winter – find a day to visit when the paths aren’t covered with snow, and notice the strong axial structure of the perennial garden.  

Continue through the perennial garden and emerge on a small side path that leads you toward the herb garden.  The designer has made use of the old stonewalls and the foundations of the old greenhouses, to plant in and among them.  This is much more interesting than if those elements had been removed.  The walls provide a backdrop for the plants; a contained and defined area that is clearly designated.  Also notice how the planting beds for the herbs have been defined – each bed is essentially the size of one of the bluestones used for the path, creating a strong symmetry, and beds are divided from one another using bluestone set on edge.  The herb garden is constructed on the footprints of old greenhouses, with the old walls as a backdrop and bluestone paths giving access to all the planting beds.

Design Principle 2:  Strive for four-season interest.  Yes, you can have flowers in winter!  At Wave Hill if you visit in February and March, you'll see winter jasmine (Jasminum nudiflorum), witch hazel (Hamamelis X intermedia), and cornelian cherry dogwood (Cornus mas) in bloom in late winter.  Additional elements with winter interest include red and yellow twig dogwood, pussy willows, black pussy willows, architectural trees (like magnolias, beech, hornbeam), seed heads, exfoliating bark, and berries.

Lagerstromia (Crapemyrtle) bark is fabulous anytime, but especially glowing in the winter sun.

Design Principle 3:  Plant a tree!  At Wave Hill you will find lots of “specimen” trees, both large and small.  A “specimen” tree means that the tree has been planted by itself or in a small grouping so that its attributes can be appreciated.  You'll see Lagerstromia (Crape myrtle), Parrotia, Magnolias, Paperbark Maple, English Oak, Dawn Redwood, Elm, Copper Beech, Weeping Beech and Hornbeam.  You can have any of these trees in your landscape as well, provided you have the appropriate conditions of wet-dry-sun-shade for the tree you’ve fallen in love with.  Notice how the trees at Wave Hill are placed relative to the paths and the beds in places that “make sense” visually – they are connected to their surroundings.  Notice that many of them are simply planted with a mulch circle around the base.  This is an excellent way to include a specimen tree in your own landscape, without feeling that the tree needs to be under-planted or included with other shrubs in an elaborate island.

Design Principle 4:  Add annuals effortlessly to your landscape by using containers.  The strategy used by the designers at Wave Hill to add annuals to the garden is to plant a single type of annual in a container and then group containers together.  Containers with different shapes and sizes are selected, then arranged to form a tapestry of color, height and texture.  When one type of annual gets past its prime, the container is simply removed from the design and a new one is introduced.  Using this trick, you can keep your annual displays looking fresh all through the season.

Design Principle 5:  Take time for tea.  At Wave Hill, outdoor chairs are moveable, plentiful and weatherproof.  You can bring a chair under a tree, out into the sun or under the pergola.  You can sit by yourself or in a group.  Talking, reading, or just sitting is the order of the day.  You can sit on the terrace by the Café and be amazed by the majestic view of the Palisades.  Sip tea.  Munch on a cookie.  Have lunch.  Invite a friend.  Recharge your batteries.  Revel in the changes of the seasons.  Take this principle to heart for your own garden.  Sit in it.  Enjoy it.  Take a break.  Feel the quiet even as you hear all the noises of birds and kids and distant (or maybe not so distant) leaf blowers.  

Wave Hill is located 675 West 252nd St., Bronx NY.  Call 718-549-3200 or visit www.wavehill.org for more information.