All posts by Katherine Tracey

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?

Mukdenia rossii ‘Karasuba’


Mukdenia should be grown in more gardens and I will speculate why it is not; it has had the misfortune of having more than one Latin name, which gets confusing. For awhile the taxonomists declared it should be called Aceriphyllum rossii, which makes sense (Acer = maple) and the foliage does have exquisite rounded maple like leaves. The cultivar name has a translation that would be easy to remember as well, ‘Crimson Fans’.

I am sweet on its blossoms. In mid spring, Mukdenia produces sturdy 15-18” stems bearing rounded panicles of starry white flowers, just before and as the foliage appears, welcoming the bees into the garden. Mukdenia makes pleasant company for early blooming bulbs and Epimedium. The somewhat glossy, somewhat velvety, dark green foliage forms tight clumps to 12” tall, keeping their good looks all summer, then change vividly to brilliant shades of red when cool temperatures arrive in autumn. We’ve found that Mukdenia grows best with afternoon shade in a soil that has good drainage yet is fertile and adequately moist. You will be pleased to know it is hardy in zones 4-8 and is also deer resistant.

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Hungry for Color, and Dahlia Ramblings

Clockwise from upper left: Dahlia 'Crichton Honey', Dahlia 'Gitt's Crazy' with Tithonia, Closeup of Gitt's Crazy' and 'Crichton Honey', Dahlia 'Corona'

Clockwise from upper left: Dahlia ‘Crichton Honey’, Dahlia ‘Gitt’s Crazy’ with Tithonia, Closeup of Gitt’s Crazy’ and ‘Crichton Honey’, Dahlia ‘Corona’

I don’t know about you, but I’m getting ravenous for color. Here in MA, spring seems so far away. Every other day there is a major snowfall in the forecast, along with frigid temperatures. Looking out my window, I only see white, on shades of brown and gray…not even a hint of green from snowdrop shoots, our earliest bulb to bloom.

As I was scanning through images from last summer’s garden, my gaze stopped to absorb the vibrant color of the Dahlia beds. Oh baby, what a color fix! I immediately went out to the cool winter greenhouse to check on the health of the tubers I’m wintering over…so far, so good. The tubers are stored in pots of well drained potting soil, and  I decided to move a few of them into the warm greenhouse (55 degrees) to try awaken them. As soon as there is enough healthy growth, I’ll take cuttings of these named cultivars. The cutting grown plants will bloom this year, but may not get as large as the plants grown from year old tubers.

Clockwise, from upper left: dark leaved selections from 'Twinings After Dark' seed, The "whitest" of the group, and the much sought after Dahlia 'Swan Lake'.

Clockwise, from upper left: dark leaved selections from ‘Twinings After Dark’ seed, the “whitest” selection of the group, and the much sought after Dahlia ‘Classic Swan Lake’.

Last year I grew a dark leaved variety of Dahlia from seed, collected from an older cultivar called ‘Twining After Eight’, which boasts chocolate colored leaves with white flowers. The description reminded me of another cultivar we once grew, and lost,  Dahlia ‘Classic Swan Lake’. The ‘Twining After Eight’ seed came from a reputable seed merchant, and the seed germinated well with most seedlings showing a nice dark foliage color.  The only thing that disappointed me was not a single plant had white flowers…half of the plants bloomed orange-yellow and 3 were in various shades of pale pink/ lavender/cerise. You might consider the palest one an almost white, in just the right light. These plants grew robustly and created a pleasant display which provoked many complements, so it wasn’t a bust.

Here are some things you might want to know about growing DahliasDahlias are native to Mexico and Central America and love lots of sun and warmth. Most of the best forms are propagated by division of the tuberous clumps or are grown from cuttings, and there is wide variety of named forms available from Dahlia merchants. Seed sown strains do not usually come true to color or form, and much of the seed commercially available is for short stemmed, small flowered varieties suitable for bedding and containers. I prefer taller forms for cutting or for showing off in the late summer/fall garden. Tall forms can be grown from seed, but again, there is no predicting color and most will have single blossoms. I don’t want to dissuade you from trying to grow Dahlia from seed, as I ended up pleased with my pink/purple blend last year, but be open minded about the results.

Fresh seed takes 7-21 days to germinate, depending on conditions, and will grow more evenly if provided with bottom heat. Once seedlings develop a couple of pairs of true leaves, prick seedlings apart and repot  individually in small pots or 6 packs. Give the young plants lots of sun, and wait until the soil has warmed to 60 degrees or more (for us here in MA, it is safe to plant Dahlias outdoors around Memorial Day). Pinch back to encourage bushiness. The above upper left image shows the seed sown plants beginning to bloom in our garden in late June, which actually was weeks before many of our tuber grown plants began. The floral show kept getting better and better until the frost.

P.S.  We have Dahlia ‘Classic Swan Lake’ tubers on order from a European supplier. Fingers crossed that they arrive safely in March. Stay posted.

Better to Have Loved, and Lost


Variegated Cornus contraversa in the distance with Osmanthus decorus revealing just outside the archway.

Better to have loved, and lost, I say.

January is a good month to take inventory. While organizing files and space in my office, I realized it was time to discard extraneous paper and to relegate numbers of old magazines and catalogs to the recycling pile. This took longer than I planned…some of these periodicals were from the 1990’s and 2000’s when my hunger for discovering new plants was unquenchable…so of course I had to revisit these dream books which held the promise of the gardens I had envisioned in years’ past.

As I scanned the dogeared pages of these old plant lists, I realized there were many, many plants that I had ordered, loved (for a season anyway) and lost. Sometimes the failures were due to my attempts to push hardiness (did I really think I was living in zone 7B after one mild winter?), or I definitely did not site the plant in the proper spot nor tend to its specific cultural needs. This is part of the education of a gardener; experimentation is exciting, and you learn much from your failures. Lessons, some of which I still struggle with such as: Was the soil too acidic (next time, sweeten the soil with ground limestone), did its placement in the garden not have good winter drainage (then add shovelfuls of coarse sand), would the plant have fared better if had been sited close to a stone wall (which might have retained more heat, adding a half zone of warmth in colder months)? Should I have put down that protective winter mulch, once the ground froze? And then there is the most hard to admit explanation….these plants just didn’t like growing in my garden.


Old nursery catalogues that I cannot part with.

I couldn’t help feeling wistful for my plant losses, but I think I was saddened more that hundreds of plants which were named in these 10-20 year old catalogues and magazines are now seldom seen on nursery plant lists. As I perused the old catalogues from Asiatica, Seneca Hill, and Heronswood, I remembered what treasures these nurseries were to gardeners. The nursery owners catered to fellow plantaholics who would swoon with delight at the discovery of a new species; alas, there are fewer and fewer of us, or so I hear. My hope is that most of these plants continue to exist in private or botanical gardens, and are not lost forever.

Eucomis zan

Eucomis zan

But enough of this doom and gloom talk; I should add that my glass is more full than empty. Many of the obscure yet lovely specimens that I planted still live on in my garden: the now 30’ Betula ermanii, the hardy Osmanthus decorus, the pretty in pink Aster ‘Kylie’ purchased from Heronswood, the collection of Anemonella from Asiatica, and the not quite hardy but easy to winter over in a pot Eucomis zambesiaca from Seneca name just a few.

I’ve decided to hold onto some of these catalogues from years gone by. They remind me of my evolution as a gardener, that there are still treasures waiting to be discovered and that there are gardens yet to be. Despite losing some plants which I loved, I am reassured that this is part of the process of creating a garden.