Tag Archives: late summer color

Euphorbia corollata

Euphorbia corollata

I think I know the reason why few people grow this easy care, refreshing native plant, commonly called Prairie Baby’s Breath: plants, even young seedlings, transplant poorly. The happiest plants have planted themselves, like this clump that adorns our front walk entry right now; it was sown in situ. Of course, you need to have a mother plant nearby to have these babies come up on their on accord, and that’s a “chicken or the egg” dilemma. We always have a few potted plants here at Avant Gardens but because they usually look weak and spindly, they are not an easy sell….unless you happen to visit our nursery and gardens in August. Now, everyone marvels at this “different baby’s breath” when they pass by.

Once established, Euphorbia corollata asks for little but sunshine and well drained soil. It begins to bloom heavily in mid July and carries the show through the month of August. I haven’t tried it as a cut flower, (it is a spurge and has that milky sap), but maybe I should experiment with sealing the stems with a flame, which will prevent that sap from poisoning the vase water. Perhaps it would be prudent to stress that some people are very sensitive to Euphorbia sap and can get serious skin irritations when exposed to it. Fortunately for me it has never been a problem.

Euphorbia corollata is hardy in zones 4-7. We planted it in our gardens more than 20 years ago, and it is still there, a testimonial to it’s longevity, often popping in new spots, especially well drained pockets. Should it sow where you don’t want it, just pull it out. In addition to being quite attractive to beneficial insects, such as bees and wasps, it isn’t a plant deer or rabbits will likely munch on, since it is poisonous if ingested.

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Calamintha nepeta ssp. nepeta

Calamintha nepeta ssp. nepeta

At last, we found an image that displays Lesser Calamint,Calamintha nepeta ssp. nepeta , in a flattering light. Perhaps that’s why more people don’t grow it: it doesn’t always photograph well, and it’s not in bloom when everyone is plant shopping in April and May. It has been one of our “go to” plants when designing sunny gardens for years. Here’s why.

Calamintha nepeta ssp. nepeta has grown well in our garden for the past 18 years. Yes, the same specimens, planted in 1995, return each year true to form. In spring they present as tidy little subshrubs (no, it does not spread by runners) with mint scented, slightly shiny leaves.  In July (June in warmer zones) sturdy 18″ stems bearing racemes of airy blue tinted white flowers appear, creating a cloud like effect for the front of the border and accenting any plant around it, and it is especially complimentary to roses. The blossoming continues into October, when the flowers take on blue tones with cooler temperatures.  Calamintha nepeta ssp. nepeta is a primo plant for attracting bees, butterflies and beneficial insects. This form of Lesser Calamint has rarely self sown in our gardens, unlike the very similar  Calamintha nepeta ‘White Cloud’, which seems to happily self sow. You might like having babies, or not. You decide.

As mentioned before, this is a reliable perennial (18 years and still going strong) for us here in southern New England. Calamintha nepeta ssp. nepeta performs well whether we  are having a hot dry summer or a cool moist one. It likes a soil that is well drained, but does not need or want lots of fertilizer. I know it will be this reliable in zones 5-7, but would be interested in hearing if folks are growing it successfully in zones 8 and 9.  Its tidy form and endless flowering means it can be combined with so many other plants, depending on your color scheme, but consider using it with Asclepias tuberosa, Sedum ‘Maestro’, Echinacea ‘Fatal Attraction’ or Caryopteris for strong summer interest.

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September Report: Successful Containers

I have always thought that what makes great visual art is when an object or painting compels you to look at it again and again. I feel the same way about plants and gardens, and containers. Of course, plants are constantly changing, so plantings are ephemeral compositions. Perhaps that’s why we want to take in their beauty all the more. Here are some planted containers that have looked good all summer, and still do in mid September.

Large Succulent Bowl on a pedestal, perhaps more beautiful than ever.

Composed of odds and ends succulents left over from last season, this ensemble has married well.

Aeonium ‘Schwartkop’ was the highlight of this tall river pot.

Syngonium ‘Neon’, an easy and lovely shade foliage plant.

Begonia ‘Chocolate Pink’ with Pilea and Cissus discolor

Peachy Abutilon ‘Harvest Moon’, with the adorable curly Spider Plant and a white Syngonium…great, easy pot for partial shade.

The Chocolate Mimosa Tree, Albizzia ‘Summer Chocolate’, makes a fast growing subject for container, adding height, texture, and dark coloring.

We did a posting of some planted containers in early July. A number of these containers sold, and we hear they still look smashing. As you can see, it’s mostly about foliage. What are your favorite container combinations from this season?

Caryopteris x ‘White Surprise’ PPAF

Caryopteris 'White Surprise'

Caryopteris ‘White Surprise’

What’s not to love? For three years now,  this white variegated form of Blue Mist Shrub has been a stunning plant in one of our sunny raised beds, providing great form, foliage and easy performance despite dry conditions and humid heat. ‘White Surprise’,  a sport of Caryopteris  ‘Heavenly Blue’, becomes a handsome 3′ x 3′ mound of aromatic white edged foliage, topped with contrasting medium blue flowers from mid-summer through September. Of particular note is how well the white edged foliage resists leaf scorch. Bees and butterflies flock to the whorled clusters of blossoms. It pairs well with so many other long season interest plants, such as Echinacea ‘Virgin’, Alstroemeria ‘Mauve Majesty and Sedum ‘Maestro’ .

Grow Caryopteris ‘White Surprise’ in well drained soil in full. It is hardy in zones 5-9, although there may be more winter die back in colder climates. Not a problem though: just cut it back hard in mid spring. Caryopteris is deer resistant, and it’s lovely white/green/blue coloring is a cooling sight in the hot summer garden.

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Gentiana ‘True Blue’ PPAF

Blue. Not only blue, but ‘True Blue’… that is the name hybridizer Darrell Probst chose for his selection of this long blooming Gentian.

Here?s been our experience. This is the third year ?True Blue? has spent in our garden, and it seems quite happy where we planted it: at the top of a stone retaining wall, in well drained rich soil, in a partly sunny spot (4-6 hours a day).  Gentiana ‘True Blue’ begins to bloom by mid July and carries on through the summer heat into September. Our plants have only have grown to 12-15″ in height, although all the literature suggests it can grow to 2′ or more.  Darrell suggests that we plant this Gentian in a more fertile soil to attain full height, and I”m ready to find a few more spots in the garden that will accommodate this lovely specimen.The 2″ chalice shaped flowers face upward, catching the morning dew.

Hardiness range is USDA zones 3-8. Darrell shared in the comments box that the parents of this hybrid are of Japanese or Korean ancestry, perhaps G. makinoi, and not from more fussy alpine regions. All the more encouragement you need.

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Euphorbia ‘Ascot Rainbow’

Euphorbia 'Ascot Rainbow'Those of us in northern climates are suspicious when we’re told showy evergreen Euphorbia are hardy for us (zone 6), with good reason. Arctic winds and lack of snow cover often dessicate the foliage and those the early blooms. Well we’ve had mixed results with the fabulous Euphorbia ‘Ascot Rainbow’, and what we’ve learned is it’s all about siting. That being said, we’d grow this plant regardless of winter hardiness because it looks good for the entire growing season, from early spring into December.

Euphorbia ‘Ascot Rainbow’ is a selection of E. x martinii. It boasts beautiful gold and green variegated foliage tinged with coral red, especially on the new growth and when temps are cooler. Multiple red stemmed branches form 18-24″ mounds. Euphorbia ‘Ascot Rainbow’ blooms on new and old growth, with adorable variegated bracts exposing tiny red flowers. I’ll say this again, this plant looks fabulous the entire growing season here in New England, and because of this it is equally as wonderful in containers as it is in open ground.

Now in regards to siting: we used Ascot Rainbow in container plantings at an urban restaurant, where they looked so fabulous at the end of the winter  that we left them in for the spring display. Really! In this protected spot, surrounded by buildings radiating heat, the Euphorbs were quite happy. In open ground we’ve had mixed results. In a raised bed with good drainage the plants came through, although we had to cut back the sad looking evergreen foliage after the winter. Snow covered much of the ground during the winter of 2010 and 2012  and our plantings came through unscathed. The recommendation: good drainage, protection from wind,  in sun or partial shade.

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Sedum sieboldii

Sedum sieboldii on the left, next to Sedum cauticola

Hmm….October Daphne. Well, it’s a bit of a stretch to say this delightful sedum is reminiscent of a Daphne, but  if I use my imagination I might convince myself. Perhaps there is a bit of a resemblance to one of the low creeping forms. Regardless of whether the common name is misleading, little Sedum sieboldii adds a dose of autumn color to the late season garden, with clusters of rosy pink flowers at  the tips of arching stems, clothed with pink and apricot tinted blue green scalloped foliage.

Botanical nomenclature now wants to classify this form of Stonecrop as Hylotelephium, but for the sake of common knowledge let’s continue here using the genus Sedum. Sedum sieboldii begins the spring season as a tidy rosette of almost turquoise fleshy scalloped leaves that develop a lovely wine red edge. The form and foliage work well all season and then informally transform in early fall, when the stems begin to extend, flower and develop October color. It is super hardy (we’re talking zone 3 here). It is most often used as a rockery subject, tucked into crevices where it remains quite happy, but we’ve left it outdoors in frost tolerant pots and it returns in the spring unfazed. Obviously Sedum sieboldii  likes well drained soil, but we’ve found it to be quite forgiving of average soil conditions.

Lespedeza thunbergii ‘Gibraltar’

Bush clover in blossom waves
without spilling
a drop of dew
—- Matsuo Basho

If you had to choose one plant to fill your late summer garden, you might consider the lovely Japanese Bush Clover, Lespedeza thunbergii ‘Gibraltar’. This selection was discovered by the accomplished plantsman, Bill Frederick, at Gibraltar, one of the duPont family estates in Wilmington, Delaware.  We have to admit ‘Gibraltar’ is a big show-off, quickly growing to 5-6′ tall and in just a few years occupying an 8-10 sq. ft. area quite easily. It loves a sunny spot and is hardy in zones 5-9.

 Lespedeza thunbergii ‘Gibraltar’ is in the legume family, and this means it does not require a rich soil, but prefers one that is a lean and well drained. To manage its size and form, you should cut the woody stalks hard to the ground in early spring. This may seem alarming at first, but Bush Clover blooms on new growth and  the full height will be attained by mid summer. A bevy of cascading branches adorned by an abundance of purple pink pea blossoms will add eye catching color from late August through September.

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Tricyrtis formosana ‘Gates of Heaven’

Just the common name, Toad Lily, sparks curiosity and invites close inspection. The delicate blossoms of this attractive cultivar of Tricyrtis formosana resemble small orchids and have distinctive spotting on the blue-violet petals. Flowering interest begins in early August, but the golden yellow foliage adds color early in the season. Plants are stoloniferous, forming small clumps 12″ high, making it suitable for the front of a border. Small Hosta such as ‘Wogon Gold’ and Japanese Forest Grass Hakonachloa macra make excellent companions.

Grow Toad Lilies in a soil that stays uniformly moist, yet well drained. The foliage tips will brown if the soil becomes too dry, and although not lethal, will make the plants less attractive. Tricyrtis ‘Gates of Heaven’are unappetizing to deer, and are hardy through zone 5-9. 

Kirengeshoma palmata

Waxbells, as Kirengeshoma palmata is commonly called, is an herbaceous perennial with a shrublike habit that adds striking foliage and sweet pale yellow flowers to the late summer shade garden. The flowering display begins in mid August and continues through September. Earlier in the season, the large maple like leaves add bold contrast to the many delicate textures that predominate in our beds. Kirengeshoma may be a little late to break dormancy in the spring, since the new shoots are quite frost sensitive, but once it finally feels the weather is safe, it quickly grows to a height of 4-5′.  With time, plants form large clumps 3-6′ across.  And if you need another big plus, the deer dislike it.

Kirengeshoma is native to the woodlands and low mountain regions of Japan and Korea, which accounts for its hardiness through zone 5.  It grows best in a rich, slightly acidic soil that is moist yet well drained. Propagate by seed or by division in early spring. We like to associate Kirengeshoma with blue and gold Hosta, such as ‘Deep Blue Sea’ and ‘Brother Stephan’ as well as late blooming Actaea ‘Hillside Black Beauty’ .

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