Category Archives: Plant Portraits

A native Aster you should be growing!

Sky Blue Aster. It’s Botanical name is quite a mouthful, Symphyotrichum oolentangiense, and yes we’re fans of  its former and much more appealing name Aster azureus. This beauty is a late summer/early fall prolific bloomer with masses of sky blue-lavender flowers on stiff 2-3’ stems that rise above ovate to oblong basal foliage.  It is found throughout much of eastern North America in dry, rocky, “edge of the woodland” habitats, but will grow in most garden soils that have good drainage.  Plants spread by rhizomatous roots, so expect it to form colonies where it is happy! Like most asters, it is a favorite of many beneficial insects, bees, butterflies and moths.

Combine this aster with Bigelowia nuttallii in the foreground (Rayless goldenrod… a great undiscovered native with clusters of tiny yellow flowers held above evergreen grassy foliage clumps,) and/or any of the taller Goldenrods, such as Solidago ‘Solar Cascade’, and native grasses like Sorghastrum nutans (Indian Grass) and Schizachyrium scoparium (Little Blue Stem).

Oh yes, it likes full sun, and Symphyotrichum oolentangiense is super hardy…it grows  in zones 3-8.

Buy online.

Vernonia’s time has come

A ;ate summer tapestry with Vernonia

Valued for its vibrant purple flower clusters as the gardening season wanes, Vernonia, commonly called Ironweed, is a must have for a pollinator friendly garden, and there are native forms hailing from the midwest and southern Appalachians. The common name may derive from the sturdy nature of its stems, or possibly the bronzy tan coloring of its seed heads that remain well into late autumn. The genus name honors the British botanist William Vernon, who catalogued plants on a visit Maryland in the late 1600’s.

Vernonia gigantea with tall Joe Pye Weed

We’ve had a tall form of Vernonia in our garden for a couple of decades. When I say tall, I’m talking  6-8’ tall depending on the soil moisture level that year. We purchased it as Vernonia altissima which is synonymous with Vernonia gigantea.  All too often folks shy away from tall plants, but I think that’s a mistake. Looking eye to eye, or even up at the blossoms and pollinator activity adds a dynamic  dimension. If you have very narrow planting beds, I can understand being hesitant to add such stature, but there’s a remedy…expand the size of your beds.

Vernonia lettermanii coloring in late day light

There are many Vernonia species (Kew lists over 300), and yes, some have a more restrained height. Take Vernonia lettermanii ‘Iron Butterfly’, which can fool the eye early in the season with its thread- leaf Amsonia-like foliage. It grows to 24-30” in height and becomes covered with purple flower clusters in September.

Vernonia ‘Summer Swan Song’

A number of good hybrids were recently developed at the Chicago Botanic Garden. Vernonia ‘Summer Swan Song’ is hybrid of V. lettermanii and Vernonia angustifolia ‘Plum Peachy’. It grows to about 3’ tall and wide. Vernonia x ‘Summer Surrender’ is similar in appearance but grows larger, up to 4’ tall and wide. A note about ‘Plum Peachy’, we like it for its dark tinted stems but it has proven to be slightly less hardy than its hybrid forms.  Perhaps it’s best to grow it in climate zones 6 and warmer.

Vernonia angustifolia ‘Plum Peachy’

As mentioned before, there are many other species of Vernonia, but I’ll describe one more. This year we are growing Vernonia crinita (aka V. arkansana) which is also native to the Ozark’s. It blooms a bit earlier than the others, in mid-late August, and grows 5-6’ tall. The clusters of purple asters it produces provide nectar to butterflies and bees.

Vernonia crinita

Vernonia pair well with Ornamental Grasses, Solidago, Eupatorium and Helianthus. They prefer moist soil with good winter drainage, but adapt well to a range of soil types. Vernonia are somewhat deer resistant, but watch for bunny nibbling on the new shoots when they first emerge in the spring. We treat with a rabbit repellent such as Plant Skydd.

buy online

The Forgotten Lantana

Lantana montevidensis

Why do we grow  this old time trailing Lantana ? Well, this species, L. montevidensis,  native to Montevideo, Uruguay, seems to be in bloom absolutely forever, without any deadheading to speak of.  Where it is hardy in zones 8-10, plants can form low 1-2’ shruband since it spreads, it works well as a ground cover. For us here in New England, plants delightfully stay under 8” and are a terrific easy care spiller for containers. Years ago, our friend Allen Haskell, a well known horticulturist from New Bedford MA, introduced us to this form. Allen used this Lantana for his topiary standards...he would select a plant with a long stem, stake it to become a trunk, and then pinch back to form rounded crowns. Since this plant is always in bloom it was an awesome  topiary subject.

the white form of Lantana montevidensis

We like a more casual approach…we add Lantana montevidensis as a spilling flowering accent when used in big pots along with ornamental Grasses, Heuchera villosa, Rudbeckia and Gaura , creating an “in the meadow” effect. Note that Lantana montevidensis tolerates drought well once established; when grown in containers it may need  little more hydration. Plants are deer resistant and tolerant of salt spray, but are toxic to dogs and cats (though we have never had any of our pets be curious about them).

We grow both the lavender well as the white form, Lantana montevidensis alba, which is just a tad less vigorous. Both butterflies and bees are frequent visitors.

Buy online:

Growing Biennial Angelica

One of the stars of our late summer pollinator garden is Angelica, whose umbels of tiny flowers invite insect and butterfly activity galore.  Angelica are biennials, and most of you know this  means that seed sown this year grow roots and foliage, with flowers appearing in year two. The hope is that once planted, the Angelica will self sow, providing progeny for years to come. Hmm, sounds good, but….

Angelica germinates best after the seed has been exposed to cold temperatures. If plants are allowed to self sow in the garden, the seed naturally gets a long winter chill, and wakes up with the spring rains. When this works, it’s wonderful! In our experience this is not always something to be counted on. What if the seed germinates but then a dry spell settles in and you are too busy to observe and water?

We choose not leave our supply up to chance. After collecting seed in the fall, we store it envelopes in a cool dry space. In February we sow the seed in a slightly dampened germinating mix and let it sit for 2 weeks at room temperature (60-72F). We then transfer the seed flat, enclosed with a sealed baggie, into the refrigerator (35-40F) for 4-6 weeks (you could also try leaving the flat in a safe spot outdoors). In April, we transfer the seed flat out to germinate under 60-70F conditions. Once the seedlings have developed first true leaves, we transplant them into deep 2” tubes (Angelica do develop a taproot). When plants are established enough they can be transplanted into the garden, or in our case, into deep nursery quart pots for retail sales.

Angelica atropurpurea

There are numerous species; here are a few of our favorites. Angelica gigas, native to Korea has bolder foliage with dense deep wine globular umbels. Angelica stricta ‘Purpurea’. (aka A. sylvestris purpurea) hails from northern Europe and has dark tinted stems and foliage, with 4’ stems bearing dark purple flower buds opening maturing to lavender-pink, followed by attractive seed heads. There is a species native to parts of the US, including New England, Angelica atropurpurea, (Purple angelica) which has medicinal uses, plus it is quite ornamental with tall  red tinted stems and green to white umbels.

If you want to grow Angelica in large swaths of your garden, why not order seed and sow this winter. You’ll have to wait a year for blossoms, but you’ll have dozens of plants. Or, compromise. Purchase a few established first year plants and get them in the ground this year for color and activity next, but still sow seed next winter for your endless supply.

Buy online

Hydrangea involucrata

Rosebud Hydrangea stands out in a crowd, despite its small stature. Slightly fuzzy soft green ovate leaves adorn the branches and it slowly grows into a 3-4’ x 3’-4’ shrub (more like 4′ in mild winter climates). From rosebud shaped  buds emerge blue lace cap flowers…clusters of tiny lavender-blue flowers are surrounded by white 4 petaled florets. It often dies back to the ground for us each winter, but since it blooms on new wood it always provides a show for us in late summer. (My honeybees descend on it as a pollen source in September.)

The literature suggests growing Hydrangea involucrata in part shade, but we’ve been growing this Hydrangea in full sun in sharply drained soil and have had it in our garden for 15 years. It has put up with weeks of dry condition this summer without looking thirsty, but we finally gave it a good soaking after the last forecast of rain didn’t materialize.

Plants are hardy in zone 6-9.

buy online

 

Best Vine for Shade: Schizophragma hydrangeoides ‘Moonlight’

Japanese hydrangea vine

For an easy and fast growing woody vine for partial or rather  shady spots, consider Japanese Hydrangea Vine, aka  Schizophragma hydrangeoides ‘Moonlight’.  Similar but visually different (and IMHO more lovely) than its cousin Climbing Hydrangea (Hydrangea anomela petiolares), the cultivar ‘Moonlight’ has faint silvery mottling on it’s dark blue-green heart shaped foliage. In July and August, it bears large (up to 9″) white “lacecap” flowers that are composed of teardrop shaped sepals attached to the tiny fertile flower clusters.  Although it is not native, the fertile flowers do invite pollinators. Plants come into bloom more quickly than do Hydrangea anomela petiolares, plus its flowers last longer and can be controlled to 10-15′ tall, although it can get taller with age.

Grow Schizophragma hydrangeoides ‘Moonlight’  espaliered up walls, pergolas and arbors or even over stonewalls. It enjoys  a rich evenly moist well-drained soil for quickest growth. and plants are hardy in zones 5b-9.

Buy online

The Prettiest Grass…Melinus nerviglumis


Ruby Grass is really truly one of the prettiest ornamental grasses ever, especially when illuminated by end of the day light. Blue-green leaves form tidy clumps and in mid-late summer, ruby pink inflorescences are formed on 18-24” stems.  It likes full sun and heat, and although somewhat drought tolerant, prefers average moisture conditions. Besides offering a casual elegance to planting  beds or containers, Ruby Grass is a stunning addition to floral arrangements both fresh and dried.

Melinus nerviglumus is native to South Africa, and is evergreen where hardy (in zones 8-10). It grows quickly to flowering stage in areas with warm summers so don’t hesitate to use it as an annul accent. Clumps can be wintered over in a cold frame or protected spot that stays above freezing.

PS  We’ve seen this listed as both Melinus and Melinis in botanical literature, & to add to the confusion it used to be called Rhynchelytrum.

Buy online

The Forgotten Hellebore

No, I’m not referring to the legendary Christmas Rose, Helleborus niger. I am suggesting that this lovely winter bloomer, Helleborus foetidus (pictured above), should be more widely grown. Unfortunately its specific name is Latin for “foul smelling”, and thus is commonly called Stinking Hellebore. Take note, in case you are already prejudiced, that I have never detected a smell, foul or otherwise.

What Helleborus foetidus does offer are lovely clusters of celadon green  bells sometimes as early as late fall or early winter. The flowers begin forming in November, and emerge on caulescent stems above dissected dark green foliage. Unlike the familiar Lenten Rose hybrids (Helleborus orientalis), these babies bloom on past season’s growth. A mild start to winter will encourage H. foetidus to flower away on the shortest days. If more frigid temperatures take hold, no harm is done; the blooming picks up again at winter’s end. Once the flowers set seed, the branched stems die and then need to be cut back. This encourages a surge of fresh new foliar growth.

You may ask why this plant is often overlooked. Blame its common name, perhaps, but it is not a patented and cloned variety; you need to grow this species hellebore from seed.  It is perfectly hardy in zones 5-9, is easy to grow in either sun or shade in a well-drained soil, and in our garden it self sows, always in the right spot. I don’t consider this tendency to be a nuisance, but a good thing. Helleborus foetidus is not extremely long lived, and its seedlings insure future plants.

So here we have a perennial that blooms when little else does, grows in sun or shade, is deer resistant, with flowers that are visited by the earliest foraging bees.  Is it time to add this forgotten Hellebore to your winter garden?

 

The Late Asters that should be in your Garden

Symphyotrichum x Bill’s Big Blue’

Years ago, the only fall asters that were commonly available at nurseries were cultivars of New England Asters: ‘Purple Dome’,  ‘Alma Potschke’  and ‘Wood’s Blue’. I have to say they have regularly disappointed me…by the time they came into flower their lower leaves would turn brown and look so tarnished.  I learned that their “ugly legs” could be disguised by planting behind another plant so you only viewed the flower heads. These New England Asters bloomed in early-mid September and by this time of year (mid October) the show was over.

Over the years, I have discovered there were so many other showy asters to try,  including many other native species.  Some didn’t begin their show until mid October,  plus they did not suffer the “ugly legs” syndrome. (Light frosts were not a problem.) Let me talk up a few.

Symphyotrichum ‘Bill’s Big Blue’

Consider Symphyotrichum (Aster) Bill’s Big Blue’, a “nativar” selected by a CA nurseryman years ago.  It may take a year or two to achieve its capable height of 5′, but here it is in the latter half of October, billowing forth over a stone wall. (Blue is sometimes tricky to capture in photos, and it is actually more blue in person). The bumbles and honey bees are enjoying its late display.

Aster ageratoides ‘Ezo Murasaki’

I’ve written about Aster ageratoides ‘Ezo Murasaki’, a small flowered October into November bloomer, in an early post.  1″ violet blue flowers appear in profusion on 18-24″ tall plants and please the bees too! Take note that this Aster spreads, so use it where a useful, late blooming groundcover will complement some brilliant fall foliage.

Aster tartaricus ‘Jindaii’

Aster tartaricus ‘Jindai’  is another late bloomer that reaches a 3-4′ height. Distinctive large tobacco-like basal leaves give rise to tall sturdy stems bearing clusters of periwinkle blue  flowers with abundant pollen. Plants do spread where happy, so pair with sturdy partner plants.

Symphyotrichum ‘October Skies’

The native Aromatic Asters, Symphyotricum oblongifolius ‘October Skies’, and the slightly taller  ‘Raydon’s Favorite’  are becoming better known. One would easily overlook them in the nursery yard in spring as their foliage doesn’t command attention.  Come October, however, and look again…the plants are literally covered with 1 1/2″ blue flowers.  They also have good drought tolerance and are pollinator friendly.

Are you growing any late blooming Asters that should be in everyone’s garden?

Fall Container Report 2021

As we approach October, it’s time to evaluate which planters held up well in this surprisingly wet year. Perhaps my favorite planter this year was an afterthought…what to do in a 36″ bowl that gets less and less sun each year. It was in an area that doesn’t get much attention to boot, but as you can see it didn’t suffer at all.

This combination of different Snakeplants (Sansevieria) and Black Mondo Grass (Ophiopogon nigrescens) with variegated ivy and Dichondra worked astonishingly well. Sophisticated in a way, but totally unfussy! Will have to consider a future repeat performance.
It’s been 20 years since we’ve grown Brugmansia (Angel’s Trumpet), but since we have had so many inquiries recently,  we decided to give them another go. (I vaguely remember that they were a magnet for whiteflies, and banned them from the greenhouse.) In June I ordered 5 different varieties from Logee’s, (yes, a late start for a summer display, especially starting with 4″ pots), but with regular doses of the  miraculous Neptune’s Harvest fish/seaweed fertilizer, they all took off. The mystery selection shown above differed from the name tag description, but it sure was quick to flower. In fact it is in its second flush right now.

This is what we learned: Brugmansia grow very fast in tropical weather conditions (we’ve certainly had  heat, humidity and a fair amount of rain this season).  We know that hybrids of the species versicolor have flowers that first appear yellow then age to shades of pink. Two of the 5 selections grew to large proportions but as of Sept 27 are only now forming flower buds.  Two others provided flowers within  3 months time.  Logee’s ‘Pink Champagne’  (pictured above) has a subtle coloring that is best enjoyed up close. The larger proportioned  ‘Angel’s Lemon Zest’ (below) has also rewarded us with repeat flowerings.

I should say that this year we’ve enjoyed simply growing on specimen plants in individual containers, and either arranging little groups or featuring  on pedestals of their own. The little Goldfish Plant, Nematanthus  gregarius, is an easy “succulent” for shadier spots. Consider it an indoor/outdoor plant..most of us have a windowsill that will accommodate this little guy for the winter,  and then next year it can renew itself outdoors again all summer.

A 20 year old pot of Haworthia reinwardtii and a 3 year old Aeolinanthus repens spent the summer outdoors, and will return to a western window inside for the winter…super easy plants to keep happy!

And now for the before and after pics.  All in all, plants held up well, although this was the year the Dichondra ‘Silver Falls’ really sulked. It didn’t die, but it didn’t luxuriate as in previous summers…too humid?A few succulents exceeded their bounds and needed a cut back.
Here the Dichondra was cut back in Sept. when it got dingy looking.You can never go wrong combining succulents with Phormium.Abutilon ‘Harvest Moon’ likes to be fed a lot, and it will  reward you with blooms all summer. Begonias may have liked the humidity but not constant wetness. Begonia ‘Art Hodes’ above, one of the best, never complained. Begonia ‘Escargot’ , below,  survived, but was more challenging to keep  happy.

Please tell us…how did your containers fare this summer? Still looking good? Which plants impressed you the most?