All posts by Katherine Tracey

3 Unique Hydrangea


Hydrangea serrata ‘Kiyosumi’

More subtle and nuanced than the big mop heads, the species H. serrata hails from the higher elevations of Japan and Korea and is considered more reliably cold hardy than most H. macrophylla. What caught my eye about this particular selection H. ‘Kiyosumi’ , even before the blossoms developed, was the attractive brick red tint to the new foliage. The 4-6″ lace caps are composed of tiny rose tinted fertile flowers, accented with a skirt of larger florets colored white to pale pink with a rim of brick red. This compact selection grows 4′ x 4′, and is hardy to -10F without stem dieback. H. serrata ‘Kiyosumi’ does bloom on old wood, and I can vouch that it survived the winter of 2014-15 quite admirably.


Hydrangea quercifolia ‘Snowflake’

An old favorite for the shade garden is the double form of Oakleaf Hydrangea, H. ‘Snowflake’. The bold oak leaf shaped foliage is handsome all season, but in early summer it bears long (10-15″) panicles of exquisite double white to celadon green florets which age beautiful to shades of pale green and rusty rose. It’s grace and beauty never ceases to draw compliments.

Like all H. quercifolia, ‘Snowflake’ blooms on old wood, so care should be taken when pruning so you are not sacrificing too many potential blossoms. H. quercifolia ‘Snowflake’ grows 7-8′ tall and wide, but the weight of the blossoms gives it an arching habit. Although this particular form can be grown in full sun if it has evenly moist soil, it has always been happier in our  cooler, shady border. It is hardy in zones 5-8.


Hydrangea macrophylla ‘Zebra’

I was recently alerted about the new Hydrangea macrophylla ‘Zebra’ from my gardening friend Barbara Smith, who suggested it as a great Hydrangea for cut flowers. (Didn’t need much convincing; I bought 3). This new patented selection is a sport of the all white cultivar H. ‘Schneeball’ (German for Snowball) and is distinguished not only for its 3.5-5″ trusses but for its very dark green foliage and almost black stems. I hear the flowers age to a wonderful pale green. Plants form compact shrubs 3-4′ tall and wide.  I suspect that this form will only bloom on old wood, so I am trialing one in a protected area and the others in a more open spot in the garden. The literature says it is hardy to zone 5, but we’ll see if that means bud hardy, won’t we?

The Other Hardy Hens & Chicks


Jovibara heufflii with small Sempervivum, Echeveria & Orostachys in the background.

The most familiar hens and chicks are in the genus Sempervivum. I’d like to introduce you to the  less familiar with same common name which are classified in the genera Jovibarba, Orostachys and Rosularia.  All are members of the Crassulacea family.

A rosette of Sempervivum flowering

A rosette of Sempervivum flowering, but with a number of offsets surviving.

Like Sempervivum, all are monocarpic, which means when the main rosette erupts into flower, it will set seed and cease to exist. (You can see why it is a good thing that many offsets of new plantlets have been freely produced.)


Jovibarba hirta ssp arenaria

The genus Jovibarba is sometimes classified as a sub genus of Sempervivum.  Jovibarba is distinguished by blossoms bearing pale green to yellow 6 petaled flowers compared to Sempervivum’s 10-12 petaled pink blossoms. There are only 3 species in the genus: globifera, hueffli and hirta. J. globifera and hirta freely produce stoloniferous offsets but  J. heufflii’s “chicks” are tightly attached to the crown, and need to be severed to propagate more babies. J. hirta ssp arenaria  forms dozens of delightful miniature rosettes (1/4-3/4”) of pale gray green leaves covered with tiny hairs. Cool temperatures bring out red foliage highlights. Grow in a lean soil with sharp drainage in hardiness zones 5-9.


Orostachys spinosus


Orostachys minutum

Orostochys is a slightly bigger genus…it includes the more popular O. iwarenge (Dunce caps) as well as several others that are garden worthy subjects. The mature rosette of O. spinosus gives the appearance of a silver sunflower with an array of silver quilled foliage surrounding a center of congested tiny tight leaves. It is hardy to zone 4-9, but requires very well drained soil. O. minutum (also listed as O. spinosum minutum) is quite petite as the specific name suggests, producing clusters of 1/2-1” rosettes of blue gray foliage. It  would make an excellent alpine trough plant.


Rosularia muratdaghensis


Rosularia serpentinica


Rosularia chrysantha

The genus Rosularia includes about 35 species. We have grown R. muratdaghensis, R. serpentinica, and R. chrysantha. Both R. muratdaghenis and serpentinica form tight mounding rosettes of gray green foliage, accented with red tones in cooler temperatures. R. chrysantha has a mat forming habit,with rosettes of soft velvety green leaves. All 3 species demand lean soil with excellent drainage and are are hardy in zones 5-9.

The before shots…containers 2015

In early summer, I take “before” images of my containers and then “after” shots in September to document how well the compositions fared over the season.  The plant selection for each arrangement is based on great foliage and unique forms. Flowering plants must be long blooming but without the constant need of deadheading.  Here are a dozen “before” pics.

For sunny and partial sunny areas….

Tall Cylinder Pot: Melianthus major, Verbena bonariensis, Heuchera 'Southern Comfort', Sedim 'Lemon Coral', Lantana montevdensis and Tradesantia 'Pale Puma'

Tall Cylinder Pot..Melianthus major, Coprosma, Verbena bonariensis, Heuchera ‘Southern Comfort’, Sedum ‘Lemon Coral’, Lantana montevdensis and Tradesantia ‘Pale Puma’

California Hydrangea Pot: Unknown Hydrange, Origanum 'Kent Beauty', Oxalis triangularis, Abutilon 'Pink Charm'

California Hydrangea Pot: Lovely, but unknown Hydrangea, Origanum ‘Kent Beauty’, Oxalis triangularis, Abutilon ‘Pink Charm’

Not flower bud hardy for us outdoors in zone 6A, but love the coloring of this dwarf hydrangea we purchased on a trip to CA a couple of years ago.

Closeup of the Hydrangea, which influenced color selection. This hydrangea, purchased on a trip to CA a couple of years ago, (don’t think it’s ‘Pistachio’), is not flower bud hardy for us outdoors in zone 6A, but makes a great container specimen.

Cast Iron Urn: The friendly agave relative, Beschorneria 'Flamingo Glow' with Cuphea hyssopifolia aura, Pelargonium sidoides, Variegated Ivy and Tradescantia 'Pale Puma'

Cast Iron Urn, starring the friendly agave relative, Beschorneria ‘Flamingo Glow’ with Cuphea hyssopifolia aurea, Pelargonium sidoides, Variegated Ivy and Tradescantia ‘Pale Puma’

Detail, showing Cuphea hyssopifolia aura and Pelargonium sidoides

Detail, showing Cuphea and Pelargonium sidoides

Hummer's Pot: hummingbird magnet Cuphea 'David Verity' with Heuchera'Southern Comfort, Oxalis 'Zinfandel', Coleus 'Tapestry' and Helichrysim 'Limelight'

Hummer’s Pot: Hummingbird magnet Cuphea ‘David Verity’ with Heuchera ‘Southern Comfort’, Oxalis ‘Zinfandel’, Coleus and  Helichrysum ‘Limelight’

White Bean Pot: Gaura 'So White, Pelargonium sidoides, Heuchera 'Obsidian'and Dicondra 'Silver Falls'

White Bean Pot: Gaura ‘So White’, Pelargonium sidoides, Heuchera ‘Obsidian’, Lantana montevidensis alba and Dichondra ‘Silver Falls’


Charcoal Urn: Pink Stripe Phormium, with a variety of succulents and Dicondra ‘Silver Falls’

And for more shady spots…


A living wreath  (sort of a vertical container) for shade: Mini Spider Plant (Chlorophytum ‘Bonnie’ )



Abutilon ‘Pink Charm, again, with Heuchera ‘Beaujolais, Pilea microphylla variegata, Fuchsia ‘Madame Daishu’ and the barely seen Ceropegia woodii (String of Hearts Vine)


Amorphophallis konjac with big Begonia ‘Wild Pony’ and petite Begonia bowerae. 

And of course: Succulents…I’ll try not to bore you with too many!


A new succulent combination for the 32″ black zen bowl…(there are too many plants to list).


Succulent Martini anyone?


Fan favorite Succulent Clam Shell.

Which container planting can you see in your garden?

PS…Check back in September to see which containers till look fabulous.

Digiplexis x ‘Illumination Flame’


Sometimes amazing things happen when you cross similar plants from different regions: Digitalis (European Foxglove) and Isoplexis (Canary Island Foxglove. The result: beautiful perpetual blooming 3′ spires of tubular flowers, which are colored sunset coral in bud and then open, exposing yellow throats with hints of apple green. This particular selection, ‘Flame’, is the first of the Illumination series introduced by Charles Valin which won the prestigious award of Best in Show at the Chelsea Flower Show in 2012.

Last year we grew Digiplexis ‘Flame’ in a large pot. It began to bloom in early June and carried on for months, well into September. The blossoms are sterile, which tricks the plants to be constantly in flower.  We brought the container into the cool greenhouse to winter over and it’s back up and about to start the show all over again. This year we’ve also planted it in our garden beds for the constant color it provides. We envision it as the vertical complement to Dahlias and Summer Phlox in a sunny, enriched , well drained border which gets an average amount of irrigation. I can attest that the hummingbirds were regular visitors, as were bees and butterflies, and I suspect it is deer resistant as well.

Because Digiplexis inherited its hardiness genes from its Canary Island parent, it will only winter over outdoors in zones 8-10, (although one of our customers bragged to me the other day that hers wintered over outdoors in a protected spot in zone 7).  Dig  up the roots after the first frost, as you would a Dahlia and store in a cool spot that stays above freezing for the winter. Gardeners in warmer winter climates don’t have to worry about this, and I can only imagine the display in their garden year after year!

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What Survived the Winter

A survivor…..Stachyurus chinensis 'Celina' cared little for being under 4' of snow.

A survivor…..Stachyurus chinensis ‘Celina’ cared little for being under 4′ of snow.

The agony and the ecstasy, or is it the other way around?
After this marathon winter, crocus, daffodils and hellebores have gushed forth with a grand ta-dah! Emerging growth from so many herbaceous perennials reassures us that a heavy snow blanket was good for some plants.

HOWEVER…. trees and shrubs exposed to the onslaught of 3 months of cold and frigid white stuff fared unevenly. Some came through unscathed, while others lost limbs and suffered dieback. The most serious casualties in our garden were the broadleaf evergreens, especially boxwood and Japanese holly, and the evergreen bamboos. The question, what does hardiness mean, is provoking a lot of discussion.

This variegated boxwood is toast!

This variegated boxwood is toast!

A variegated boxwood, which grew from a rooted cutting 15 years ago to 7′ tall, is now the color of straw and shows no green in the cut wood, except for the lowest branches. The fastigiate Japanese Holly, Ilex ‘Sky Pencil’ has more than its share of crispy foliage, but the wood has life and we’re confident it will put on fresh growth. Amazingly, once again the Trochodendron araliodes which horticultural friends cautioned would be iffy, came through looking fine, despite broken branches, (it was buried under snow for weeks). Planted right next to it was a so called hardy gardenia, a loss, or at least total die back to the roots.

A few smashed branches  reduced the size of this Trochodendron, but it's going to be fine.

A few smashed branches reduced the size of this Trochodendron, but it’s going to be fine.

The bamboo grove of Phyllostachys aureosulcata is a sorry sight. What once was a wall of green is now stationary beige. Yes, discoloring of leaves happens in cold winters,  which drop when the new leaves emerge in May, (most years)…but this year many of the 30′ culms are brown or oddly discolored. I’m confident that new shoots will break from the ground, but thousands of dead stalks will need to cut down before this happens. Know any artists who may need bamboo for a big project?

Note the brown culms, and even some of the green have threatening discoloring.

Note the brown culms, and even some of the green have threatening discoloring.

I usually advise patience before yanking out plants that have suffered winter damage. April is often too early to tell if a plant is a goner or will convalesce and recover.  In the meantime, where there is hope, prune damaged branches, fertlize gently and let nature heal. Miracles happen while you are busy watching everything else grow.

the rare little Helleborus torquatus, returning again after more than 20 years

the rare little Helleborus torquatus, returning again after more than 20 years

In Color: Hardy Succulents

Clockwise from left: Sempervivum 'Pacific Blue Ice', Sedum 'Angelina', Semeprvivum 'Carmen', Sedum album 'Coral Carpet', Sempervivum 'Topaz', and Sedum stefco

Clockwise from left: Sempervivum ‘Pacific Blue Ice’, Sedum ‘Angelina’, Semeprvivum ‘Carmen’, Sedum album ‘Coral Carpet’, Sempervivum ‘Topaz’, and Sedum stefco

It is early April here in New England, and as the snow retreats, a walk about the garden reveals color from unexpected plants…winter hardy succulents. Yes the early crocus and snowdrops are showing off, but they will come and go quickly. Since we’re still flirting with frosts and will not begin to see rich greens and bright pastels until the end of the month, the delicious burgundy and coral tones taken on by many hardy Sempervivum and Sedum provide a different color palette. These hardy succulents may not grab your attention when plant shopping, since many gardeners aren’t selecting plants at nurseries until warmer temperatures prevail. By late spring, the intense foliage hues change to more muted blue green and olive coloring. And of course, there are many more brightly colored blossoms to distract us.

If you’re taking a survey of your gardens right now, consider where you can use the rich, changing colors and textures that winter hardy succulents provide. They require minimal care and look good year round, especially the “evergreen” forms. Many are hardy into zone 3 plus are deer and rabbit resistant.  They ask only for sun and good drainage, and can winter over admirably in containers as well.

The receding snow (we had over 3′ at one point) did not harm Sempervivum ‘Carmen’ in the least.

The receding snow (we had over 3′ at one point) did not harm Sempervivum ‘Carmen’ in the least.

In bloom: Tender Succulents

graptoveria fred ives

Flowers of Graptoveria ‘Fred Ives’

Most of us select our ‘tender” succulents by virtue of their unique forms or foliage in desert tints of sage green, blue gray, dusty rose, plum, khaki gold. A few put out flowers during our northern hemisphere summers, but many warm winter succulents bloom when the day length is shorter…mid-late fall, winter, and early spring.  These succulents add astonishing color to a windowsill display while we wait for spring to really settle in.

aloes in bloom

A peak at some of our Aloes in bloom.


Gasteraloe ‘Green Ice’…a cross between an Aloe and Gasteria

I’ve been collecting “tender succulents” for more than 15 years, and one of the frustrating things I constantly come across are mislabeled plants. We now have an excuse to visit southern CA more frequently as one of our sons is living there, and since this is where more succulents are grown than anywhere else, I have made it my mission to visit botanical gardens and nurseries from Santa Barbara to San Diego in search of proper names. The most common succulent genera are Aloe, Crassula, Echeveria, Gasteria, Graptopetalum, Kalanchoe, Pachyphytum and Sedum.

What makes things very curious is that there’s been a lot of inter breeding going on, and by that I mean crossing one genus with another. For example, Echeveria crossed with Sedum becomes Sedeveria.  Because these genera are so closely related (many are in the Crassulaceae family) this works, and some interesting new plants have been introduced. This does however complicate identifying misnamed plants. The foliage isn’t always the tell tale sign; the flower formation can give better clues, but even then…take for example Graptoveria ‘Moonglow’, a cross between Graptopetalum and Echeveria.

graptoveria moonglow

Graptoveria ‘Moonglow’

The flowers of Echeveria tend to be bell shaped with many variations: tightly closed, flared, chunky, narrow and are held on short or even tall stems that can be terminated with a few blossoms or multi branched. Graptopetalum blossoms are star shaped with prominent stamens and are held on upright stems in branches of a few to many flowers. The flowers of Sedum are held in terminating clusters of star shaped inflorescences. The intergeneric crosses display a mix of these flower formations, and here is where further research is required. I plan to continue to study the differences.

sedum limeglow

Sedum ‘Limeglow’

Photo documentation is essential in keying identity. I now have a set up for plant portrait taking, and will continue to photograph the various flower forms as  plants continue to open bud.  Here are a few photos of various succulents in flower.

echeveria dondo

Echeveria ‘Dondo’

Mystery Echeveria…purchased as 'Fleur Blanc'

Mystery Echeveria…purchased as ‘Fleur Blanc’

mystery echeveria

Mystery Echeveria…also purchased as ‘Fleur Blanc’


Pachyphytum oviferum…or “Moonstones”

echeveria lola

Echeveria ‘Lola’

Echeveria parva

Echeveria parva

harry butterfield

Sedeveria ‘Harry Butterfield’


Mystery Sedeveria


Sedeveria blossom

I have yet to find an authoritative source, online or in print, documenting and clarifying information on succulents. It is a challenging task, for sure. Do you have a resource or guide you refer to? Please share if you do.


Anemone sylvestris

anemonesylvestrisweb Anemone sylvestris, is simply lovely and so innocent-looking, but perhaps it should be introduced to you as a potential ground cover. Commonly known as Snowdrop Anemone, this super hardy gem begins blooming in mid-late spring, producing nodding buds which open to 5 petaled white blossoms centered with a ring of yellow stamens. The blossoms, buoyantly dance on 12-18” stems, which are good for cutting, emit a soft early spring fragrance.   Although it is a European native, it looks right at home in naturalistic landscapes here in the US, spreading vigorously by rhizomes, and it is very effective for disguising early spring bulb foliage. The wooly seed heads that develop once the blossoms fade add visual interest later in the summer.  Occasionally, a small flush of flowering in takes place early fall.


Anemone sylvestris is happiest in a rich well drained soil, and is hardy in zones 4-8. It is not fond of extreme heat, so best to hold off in southern gardens. There are no serious insect or disease problems and it is deer resistant.

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Helleborus 'Ivory Prince with sprigs of Foxtail Asparagus and Pink Flax leaves

Using Hellebores as Cut Flowers

Helleborus 'Ivory Prince with sprigs of Foxtail Asparagus and Pink Flax leaves

Helleborus ‘Ivory Prince with sprigs of Foxtail Asparagus and Pink Flax leaves

The end of winter is upon us and the first Hellebores have begun to open, providing lush exotic blossoms for Slow Flower arranging, at last. I couldn’t help myself a couple of weeks ago and cut a bouquet from plants growing in the cold frame. Alas, after only a few hours, they had begun to flop over and looked wilted in the vase. I don’t recall this happening before, so I did some research.

Here’s a little botany. There are basically 2 categories of Hellebores: the caulescent group, which means the blossoms are born in multiples on stems produced the previous year (includes the species foetidus and argutifolus) and acaulescent group, which send up flowering stems from the plants base as winter’s end draws near (i.e. the orientalis hybrids, commonly known as Lenten Rose). In the past few decades, breeders have been crossing the 2 groups and we now have hellebores that fall somewhere in between.  The acaulescent types, meaning the showy Lenten Roses, should be picked when the flowers have aged a bit and the ovary (the seed pod in the center) has begun to swell, which is the same time that its pollen and anthers will have begun to drop. These slightly aged blossoms last longer cut (in the past, I must have unwittingly cut older blossoms). If you must pick young just opened buds, cut short stems. Note that the caulescent types, such as H.  foetidus, hold up better without flopping.   Helleborus ‘Ivory Prince’, shown here, is a cross between the 2 types, and offers the best traits of both.

Cut stems, Hot water, Dip cut stems for 30 seconds

Cut stems, Hot water, Dip cut stems for 30 seconds

The next step is to condition the stems in hot, almost boiling water. Dip the stems into hot water and let sit for 30 seconds. Remove, then place in a vase of water with a tiny bit of vodka, or about 1 T. vodka per quart of tap water.  I have read that some people skip the hot water treatment and instead sear the stems over an open flame, but that makes me hesitate.  Hellebore blossoms will hold up longer in a cool room.

Do you have a tip that you would like to share for keeping Hellebore blossoms fresh?