Category Archives: Perennials and Annuals

Herbaceous plants

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.

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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.

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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?

Two Time Tested Groundcovers To Try

Some of you will remember that many (20+) years ago, there was a wonderful specialty nursery on the West Coast called Heronswood. Heronswood Nursery turned us on to so many great new plants! Yes the climate on Bainbridge Island was much milder than ours here in zone 6, and some of their offerings would not survive our cold winters. Still there were plant discoveries that could.  One was this evergreen ground cover commonly known as Silver Veined Wintercreeper, (Euonymus fortunei ‘Wolong Ghost’).

We’ve had this planted for decades in a spot with only a few hours of sunlight. Here it has gracefully spread and spilled over a low retaining wall. Plants do not get much taller than 8-10″ but can cover an area as the stems might root along as they touch the earth. It is known to be hardy in zones 5-9, is adaptable to part sun or shade plus it is disliked by deer.

Sedum sichotense

Another ground cover we have enjoyed in our garden for years is Sedum sichotense. (now reclassified as Phedimus sichotense). Low growing (under 4″) but ever spreading, it is a superb choice for dry soil in full sun. The narrow serrated leaves add textural interest, but what is most exciting is the foliage turns shades of brilliant red in the fall .

Fall color starting to turn red

Sedum sichotense offers clusters of starry yellow summer flowers that are favored by bees. It ishardy in zones 4-9 (it’s native to a part of Russia we’re told).  And yes, it is deer resistant.

Buy Euonymus fortunei ‘Wolong Ghost online

Buy Sedum sichotense online

Abutilon ‘Dwarf Red’

Are you looking for something different for a fall display in your containers? Check out Abutilon ‘Dwarf Red’...it celebrates autumn with multitudes of dark orange flowers, and can, if brought indoors and kept in a sun filled space, will continue to carry on the show.

We grow a number of Abutilon selections  in containers which we bring indoors once the cold sets in, but if we were asked which  form to grow,  Abutilon ‘Dwarf Red‘ tops the list. It stays bushy and compact  ( it has A. megapotamicum in its lineage) when grown in 4-6 hours of sun and blooms continuously  with the biggest show in late summer and fall.  We have been caught off guard when a frosty night  has brought temperatures below 32F, and  found that  ‘Dwarf Red’  came through unfazed.

Some things to know about Abutilon. It is  commonly known as Flowering Maple,  and is a semi-tropical shrub with lovely pendant bell-shaped flowers that are attractive to hummingbirds. The flower display can continue year round when grown in bright light and temperatures above 45F, but in our experience,  the flower display in autumn is most generous. Often listed as winter hardy in zones 9-10, we have been hearing that hardiness in zones 7b-8 is not unheard of when plants are grown in a protected spot with good drainage.

CARE: Abutilons like to be fed regularly for good flower output  We use a fish emulsion/seaweed blend (Neptune’s Harvest 2-6-4 blend) every 2 weeks. allow the soil to become somewhat dry between waterings.   Purchase online.

Other posts discussing fall containers:

Rethinking fall containers

Plectranthus ciliatus

End of the Season Container Reports

Vitex agnus-castus ‘Shoal Creek’

Why plant Buddleia when you can grow Vitex?  Mid summer blue-lavender fragrant spires begin in July and carry on through August on bushy plants with attractive palmate foliage. Here in the northeast, our colder winters don’t allow plants to become as large (10-15′) as the data says, since they  do get some  winter die back.  Vitex blooms on new growth, so it can be cut back hard each spring to grow into a perfectly sized 5-6′ flowering shrub.  And yes,  it is a great addition to a pollinator garden as it is a favorite of butterflies and bees.

The fruits of Vitex agnus-castus resemble peppercorns and have medicinal properties. It has been used to treat women’s health issues such fertility and menstrual problems. In the middle ages it was used to reduce the male libido (heaven’s no!) hence its common name, Chaste Tree. Grow Vitex in full sun in well drained soil in zones (5, with protection) 6-9.

Phlox paniculata ‘Jeana’

I’ll give you 3 reasons why you should have ‘Jeana’, a Summer Panicle Phlox, in your garden.

1. Long-blooming tresses of many small lilac sized florets, on 4-5′ stems, adorn this plant from mid July-September.

2. The foliage is highly resistant to mildew.

3. Butterflies favored ‘Jeana’  over all other Phlox paniculata selections  in the trial gardens at the Mt. Cuba Center.

Phlox paniculata ‘Jeana’ is  hardy in zones 4-8 and enjoys full sun. For a pleasing midsummer vignette, combine with white coneflowers or the yellow daisies of tall Rudbeckia nitida ‘Autumn Sun’, as well as the blue spires of mid-sized Agastache ‘Blue Fortune’ and  for the front of the border airy and pollinator friendly Calamintha nepeta ssp nepeta.

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A Versatile Fall Aster

Heath Aster planted itself in the dappled shade of our oak tree.

I take no credit for planting the occasional surprise of native Symphyotrichum ericoides (heath aster) in our gardens…they just appear and often in just the right spot. Unobtrusive all summer, but a delightful accent when flowers form in mid-September, Heath Aster presents 1-2′ stems bearing hundreds of tiny white daisies with yellow centers, creating a frothy foam in both sunny and even somewhat shady areas.

Synphyotrichum ‘Bridal Veil’…a Chicago Botanic Garden Introduction. ( image courtesy of CBC)

There are selected forms out there….‘Snow Flurry’ stays quite low at  6-8″ with 2′ branches that hug the earth, making it a useful native ground cover for the edge of a border or in the rock garden. A new selection ‘Bridal Veil’, introduced by the Chicago Botanic Garden, is believed to be a naturally occurring cross of ericoides and “?”. It produces strong 2′ arching stems with copious amounts of blossoms and forms vigorous clumps.

All forms of Heath Aster prefer well-drained soil and are quite drought tolerant once established. As I mentioned we’ve had plants pop up in even shady situations, but I think you get more flower power with full sun. Deer resistant and pollinator-friendly and hardy in zones 5-8…yay!

Two Plants to add a little Fall Excitement

All summer long Plectranthus ciliatus masquerades as a khaki-colored Coleus. Come early autumn, all of a sudden floral spikes extend and open up into chunky spires of lavender-blue flowers.  It does need to be protected from frost. but we’ve solved this problem by covering plants with a blanket on those pre-Indian Summer nights when the temperatures dip. Easy peasy to grow indoors for the winter, as it can get by with indoor lighting.

Folks always admire this succulent Senecio early in the season for its display of blue-gray tufts of foliage. However, when late summer rolls around flowering stalks emerge and open up to showy 1″ red-orange buttons. Use Senecio ‘Blazing Glory in a pot by itself or mix with other succulent goodies. Yes, it is a plant that needs protection from frosts., but it is super easy indoors on a sunny window sill.