I first ran into the sticky blazing star, Liatris resinosa, a few years ago when botanizing in the eastern part of NC. Since that time, it has thrived in our garden, where we grow it in a bog with pitcher plants as well as in an alpine berm. Our plants have just topped 3′ in height as they start to flower in late August/early September. Liatris resinosa, formerly considered a variety of LIatris spicata, hails from New Jersey southwest to Louisiana. We particularly like the compact habit, sturdy stems, and small foliage. Hardiness should be Zone 6a-8b.
On my very short commute home, we’ve designed beds along the way that help relieve the stresses of the day. One of my favorite beds in summer is this combination of Allium ‘Millenium’, Sinningia tubiflora (white), Verbena bonariensis, and Pervoskia atriplicifolia. Both the sinningia and the verbena can be a bit aggressive in some areas of the garden, but not here, where they’ve all reached a happy equilibrium. Not only are they visually attractive, but this bed is awash with pollinators, despite none of these plants being southeast US natives.
No garden is complete without at least one rudbeckia. Looking good in the garden now is the lovely Rudbeckia umbrosa. Formerly recognized as a a subspecies of the more commonly grown Rudbeckia fulgida, this is a very different plant that’s taller, and with very hairy foliage. For us, this moist woodland native tops out between 30″ and 36″, with a much more open habit. Although it’s little known in gardens, it’s actually native from the Carolinas west to Missouri. Zone 5a to 8b.
The lovely Mexican woody lily, Dasylirion berlandieri, is just finishing a bout of flowering. The flowers are magnets for both native bees as well as honeybees. Unlike their cousin, Agave, Dasylirion don’t die after flowering.
Over a decade ago I decided to try planting the native Frogfruit (Phyla nodiflora) in the maritime grassland exhibit at the South Carolina Botanical Garden. To my amazement, this species that I knew of from the fringes of saltmarsh in the Lowcountry thrived in both wet and dry soils of the upper Piedmont of South Carolina! The plant has proven to have incredible versatility and grows well in sand or clay and can be flooded for weeks and completely dry as well. Unlike many other plants that can accommodate such diverse conditions it isn’t so ugly that only a mother could love it, in fact, it’s charming.
Frogfruit is a low (4” tall) trailing groundcover with 1.25” long leaves that forms a solid mass of foliage but lacks deep root structures and thus does not compete with deeper rooted structural element plants. The flowers are pale pink to lavender and resemble tiny lantanas (a close relative). The flowering season here in the south begins in April and can continue through hard freezes (typically November) but may produce flowers year-round in mild winters.
Our plants, Phyla nodiflora ‘Ramble On,’ are from a Charleston County, South Carolina collection along the margins of a wet ditch (freshwater), but the species has an amazingly wide range being found from New Jersey west to California and throughout the tropical regions of the world. Another species, Phyla lanceolata, is a more upright plant, with a similar range (but extending north to Ontario) it has longer leaves and is generally less showy as a groundcover.
This is the ideal living mulch for tough areas of your landscape. It spreads rapidly but is easy to keep contained by trimming the edges of your patch. We placed it in one of our pond overflow pits and were amazed to see it completely transform a time-sink of constant weeding into a mass of lovely little flowers while allowing the Hymenocallis and Hibiscus to continue to rise through the groundcover without obstruction.
The flowers are favored by skipper butterflies, particularly the smaller species and there is an all-day-long collection of hundreds on our patch every day. In addition, small flies, native bees, sweat bees and tiny wasps are fond of their constantly produced flowers. The leaf and stem color ranges from green to deep purple depending on the environmental conditions—generally, the more exposed to sun, intermittent drought or salty soils, the more purple in the plant. If the goal of your garden is to increase the production of life by filling all your spaces with plants that are loved by insects while at the same time reducing the need for mulch and weeding, this plant is definitely worth a try. Look for this in the near future. – Patrick McMillan.
Looking lovely in the garden this week is the amazing native small tree, Aesculus parviflora var. serotina ‘Rogers’. Despite this amazing plant being native only in Alabama, it thrives in gardens well north of Chicago. This named selection was discovered in the early 1960s in the yard of University of Illinois professor Donald Rogers, and named because of its more floriferous nature, as well as its more pendulous flower spikes.
The latest member of the clumping monardas of the Electric Neon series is ‘Electric Neon Purple’. Here it is in our garden this summer, looking absolutely fabulous. Look for this in our upcoming Fall catalog.
Looking lovely in the dryland garden now is the amazingly vigorous Agastache ‘Queen Nectarine’. This amazing giant measures 3.5′ tall x 3.5′ wide, and is adorned at any given time, May through October, with hundreds of flowers, perfectly designed for hummingbirds. Many of the non purple-flowered agastaches struggle in our hot, humid, rainy summers, but not this one. Hardiness zone 5a to 8b.
by Patrick McMillan
The past couple of weeks the small, freakish flowers of one of the strangest of plants have begun to open in our gardens – pipevines. It’s difficult to believe that nature could summon up anything as strange as the flowers of pipevines. If you remember the “regular” aka actinomorphic and the “irregular” zygomorphic flowers from high school biology then you would have to consider the strange, inflated flowers of pipevines highly irregular.
These plants are related to wild gingers/heartleafs (Asarum) and are members of the basal angiosperms, which are plants with lineages that predate monocots and true dicots. Many of the early angiosperms have flowers that are pollinated by flies or beetles that they lure to the flowers with the pleasant smell of rotting meat or dung. Pipevine is no exception. They trick flies into entering the strangely shaped flowers which often have a funnel-like flare with a narrow opening and trap the fly in a chamber with the pollen and nectar to accomplish pollination.
The general shape of the pipevine flower also approximates the anatomy of a uterus and birth canal. As was all the craze in the early years of medicine, the resemblance to the uterus must mean it is good for treating issues with difficult pregnancies and childbirth. This archaic mode of determining herbal remedies is referred to as the doctrine of signatures – basically if a plant part looked like a part of the human anatomy it would be used to treat ailments associated with that organ. This avenue of medical care led us to the highly unsuccessful use of liverleaf (Hepatica) to treat ailments thought to be caused by the liver, like cowardice and freckles. Medical science has since progressed, maybe?
The pipevines include herbaceous upright perennials, short rambling vines, and enormous lianas (woody vines). The toxic chemical aristolochic acid is contained in all parts of the plant and though it is known to cause kidney failure (which probably didn’t decrease the problems with difficult childbirth) this chemical has also been shown to have antitumor properties. Don’t go munching on the leaves! Pipevine Swallowtails depend exclusively on pipevines for their larval food source and all the species we grow are host to large numbers of caterpillars in the summer.
The Pipevine Swallowtail accumulates aristolochic acid which deters predators like birds from wanting to consume them (they don’t want kidney failure either). This may explain why Spicebush Swallowtails and Red-spotted Purples look so similar to the Pipevine Swallowtail, they’re taking advantage of blending into the poisonous crowd.
These beautiful butterflies always seem to find your pipevines, no matter how secluded you think they are. Don’t worry, we can’t have enough swallowtails and the vines regrow without issue. These are great plants to include in your garden to support our butterflies. The caterpillars have another interesting behavior, when disturbed they have bright orange “horns” that are technically referred to as osmeteria that it pushes out of the front of its body and emit a very foul odor!
Three native pipevines are found in the Carolinas. Common Pipevine (Isotrema macrophyllum) can become a huge liana, reaching the canopies of old-growth trees and spreads through runners and can be difficult to keep contained. It grows best in cool climates and tends to suffer or not grow in warmer parts of the Southeastern US.
Woolly Pipevine (Isotrema tomentosa) grows very well in hot, humid climates and is known from only a few native populations in the Carolina coastal plain. Like its mountain cousin it is very difficult to restrain and may quickly outgrow the space you envision for it.
The only other pipevine is very dissimilar to the others, Virginia Snakeroot (Endodeca serpentaria), which is an upright herbaceous perennial that rarely gets a foot tall. If you’re wondering why these former Aristolochia are now in the genera of Isotrema and Endodeca, well, it appears to all be about genetics. They are closely related but currently in different genera.
One of the easiest to grow and showiest, best-behaved species in our garden hails from Brazil, Argentina and Bolivia, Fringed Pipevine or Fringed Dutchman’s-pipe (Aristolochia fimbriata). The plants form scrambling vines that act more like a groundcover than a vine and have beautifully silver-veined small leaves. The flowers are intricately patterned with lines and fringed with long “tentacles” to create one of the most bizarre flowers you’ll ever include in the landscape. Though you wouldn’t pick a plant from Brazil to be rock-hardy here in Raleigh, this one has been fully hardy (zones 7a-9a). For those of you looking to add some swallowtails but unwilling to devote the space to a monstrous mass of vines this one is for you. Fringed Pipevine is also incredibly drought-tolerant and perfect for part-sun to dappled dry shade.
The lovely Aesculus pavia, native from Illinois south to Texas, and east to Florida, has been absolutely glorious over the last few weeks. This easy-to-grow small tree typically tops out between 15-20′ tall.
Most folks have grown butterfly bushes in the genus buddleia, yet few garden visitors recognize this fascinating species from our 1994 botanizing trip to Northern Mexico. I should add that most buddleias on the market are developed from the Asian species, and virtually none from the less colorful North American species.
Buddleia cordata ssp. tomentella grows in rocky, bone-dry hillsides in the mountains of Northern Mexico near the town of Los Lirios at 7,000′ elevation. I was only able to find a single seed, but fortunately, it sprouted, and 28 years later, this amazing specimen is the result.
One of the cool things about Buddleia cordata ssp. tomentella is the insanely fragrant flowers, which start for us in early fall, and continue all winter…a trait you won’t find in any other temperate shrub of which we’re aware. As you can imagine, it is awash with an array of pollinator insects The flower color is a dusty white, so this will never be a plant that will make it to the shelves of your favorite box store. That said, it’s a plant we wouldn’t be without in our garden.
I’d grown quite a few eryngiums…49 different ones, in fact, before Patrick shared Eryngium ravenelii with us in 2015. Who knew we were missing one of the best eryngiums in the entire genus! Today, Eryngium ravenelii holds several places of honor in our garden, where we can watch the myriad of pollinators who regularly stop by for a nectar snack during flowering season (mid-August to late September).
Eryngium ravenelii was named for American botanist, Henry William Ravenel (1814-1887). In the wild, Eryngium ravenelii grows in standing water in flooded ditches, alongside sarracenias (see bottom photo). We’ve now seen them in the wild in both North Florida and South Carolina, where they grow in calcareous-formed soils. In the garden, they thrive in an array of slightly acidic soils as long as the soil is reasonably moist.
Looking fabulous in the garden now is the perennial Salvia ‘Big Blue’. This amazing sage has been in flower since spring, and has yet to slow down. It’s also a favorite of the native bumblebees.
I’ve been surprised to see the black swallowtails regularly enjoying the nectar of the summer-flowering daphnes…in this case, Daphne x napolitana ‘Bramdream’. Our plants are thriving, growing in our full sun rock garden.
As gardeners around the country are encouraged to plant more asclepias to encourage monarch butterflies, many folks are finding out that not all species of asclepias make good garden plants. As a genus, asclepias consists of running and clump forming species. There are number of horribly weedy garden plants like Asclepias speciosa, Asclepias syriaca, and Asclepias fasicularis. These plants are fine in a prairie garden, but are disastrous in more controlled home gardens.
One of our favorite clumping species is the easy-to-grow, Arizona-native Asclepias angustifolia ‘Sonoita’. This superb species was shared by plantsman Patrick McMillan. It has proven to be an amazing garden specimen, thriving for years, despite our heat and humidity. Did I mention it flowers from spring through summer?
Gardeners interesting in attracting pollinators to the garden have no doubt experimented with one of the 20 native species of Pycnanthemum (mountain mint). While they are all lovely, most are too vigorously spreading to fit in a typical home garden. Enter Pycnanthemum flexuosum…the curvy mountain mint, is native from Virginia to Alabama, where it is found on moist to damp sites. This tightly clumping species is absolutely perfect for the garden, flowering now in July. This is our collection from Beaufort County, NC. We’ll be propagating this selection for a future PDN catalog. Hardiness is Zone 5-9a.
This is the time of year when the tiger swallowtails feast on our many patches of the amazing native Stokes aster. Our favorite clone is the upright growing Stokesia laevis ‘Peachie’s Pick’. Moist soils are best, but stokesia tolerates some dry conditions on a short term basis as long as it has 2-6 hours of sun.
If you get your gardening information on-line, where everything written is a fact, you’ll know for sure that acacias aren’t growable in Zone 7b, Raleigh, NC. If that includes you, don’t look at the photo below of Acacia greggii ‘Mule Mountain’ in flower at JLBG. Acacia greggii is a native from Texas west to California. Our seven year-old specimen is from Patrick McMillan’s collection in Cochise County, Arizona.
To be nomenclaturally correct, most of the US Acacias have now been moved into the genus Senegalia, so even though the American species aren’t from anywhere near Senegal, this is now known as Senegalia greggii.
Of course, it you also read the hogwash on-line about native pollinators needed and preferring plants they evolved with, then you’ll also have to ignore the masses of native bees that cause the entire plant to buzz while they’re feeding. It’s good we don’t let our plants and insects read books or the Internet.
A few weeks ago, we posted images of the flower spike of our Agave ovatifolia ‘Vanzie’ just beginning to spike. Now, the giant beast is in full flower. The first photo below is the plant with its full expanded stalk in full bud, just prior to opening. After that, each image shows the progression of the flower development.
Agaves are monocarpic, so those species like Agave ovatifolia that do not make offsets will die after flowering. Agave ovatifolia is, however, one of a handful of species that usually forms baby plantlets on the tip of flowers stalk after seed set.
First flowers just beginning to open
We set up our Little Giant ladder, which allows us to climb up, collect pollen and to make crosses with other agaves.
The lower flower clusters open first and flowering continues to progress each day moving higher up the stalk.
Climbing the ladder gives you a bird’s eye view of the amazing buds as they are ready to open…usually 200-300 per panicle.
Below is a half-open flower panicle. The pollen is ripe before the stigma is ready to receive pollen, so pollen can be easily gathered without worry of self pollination.
Below is a fully open flower panicle. Each panicle weighs 5-10 pounds. No wonder the stalk needs to be so sturdy. Once the temperature warms in the morning, the flowers are abuzz with pollinators…mostly bees.
Looking down from above the flower panicle makes a pretty crazy photo
Our intern Zoe is working with our volunteer agave curator, Vince Schneider to gather pollen and make crosses with other previously gathered agave pollen
I usually don’t climb this high…a fear of heights, but this photo opportunity was just too good to resist
We caught the Nessus Sphinx moth feasting on a patch of phlox this spring. Remember that garden diversity brings more fascinating pollinators into the garden.
One of the little-known native asclepias, milkweed, is flowering in the garden this week. Asclepias variegata, redwing milkweed, is a widespread native, ranging from Canada and Virginia south to Florida, and west to Texas. So, why is this virtually unavailable commercially? Our plants typically range from 1.5′ to 2′ tall, although 3′ is possible. For us, it performs best in part sun to light shade.
The specific epithet “variegata” which refers to two colors on the flower was certainly a poor choice, since most asclepias have multi-color flowers. Of course, Linnaeus didn’t have the benefit of the internet back in 1753.
If you’re able to visit during this years spring open house, it will be hard to miss the look of love in the air. We have a record 20 century plants in spike in the garden…a number far surpassing any flowering record we’ve set previously.
Agaves are a genus of mostly monocarpic plants…they live their entire lives to flower once, then after experiencing a giant-sized orgasm, they fall over dead. In the wild, many species take up to 100 years to flower, which is why the name century plant stuck as a common name. In our more rainy climate, our century plants typically flower in 12-15 years. Several of our current crop are actually less than a decade old, but their enormous size has already been achieved, so they’re ready to reproduce.
Some species of agaves offset, and in this case, only then central rosette dies, and the offsets continue as is the case with bromeliads. Those agave species which never offset are one-and-dones, but hopefully will leave behind a plethora of seed for the next generation. From the start of the spikes to full flower is usually about 8 weeks. Below are a few of our babies in spike.
What a lovely color echo we caught this week at JLBG when the tiger swallowtails were visiting Mertensia virginiana (Virginia Bluebells). Remember that botanical diversity results in more pollinators in the garden.
Here is the wonderful Fatsia japonica ‘Variegata’ in our garden on Oct 25. This fabulous shrub is a member of the aralia family, and a first cousin of the off-despised running ivies. Not only do we love Fatsia for its amazing bold texture and evergreen foliage, but we love it because it flowers in fall. The second photo was taken a mere four weeks later, when it had exploded in full bloom.
Fatsia japonica is a superb pollinator plant at a time when so little is in full bloom. Our winter low temperatures so far have been 27 degrees F, which hasn’t affected the flowers. Winter hardiness is Zone 7b and warmer.
Salvia regla ‘Jame’ (pronounced Haam-hey) is looking so wonderful this time of year. This amazing North American native (US/Mexico) was originally shared back in 2000, by the late Salvia guru, Rich Dufresne. It has adorned our gardens every year since with these amazing fall shows. Hardiness is Zone 7b and warmer.
I was fascinated to find these monarch butterfly chrysalis’s hanging out on an agave in the crevice garden recently. Our entomologist, Bill Reynolds, tells me that when the caterpillars are finished feeding, they will often migrate from a nearby asclepias to all kinds of odd plants to hangout until it’s time to come out of their closet. It’s hard to imagine a full-size monarch butterfly inside these little structures, but perhaps they are like Dr. Who’s Tardis.
Our favorite fall-flowering legume is looking fabulous now. While most daleas (baptisia cousins) flower in spring and summer, only one that we’ve grown waits until fall to produce its amazing floral show. Dalea bicolor var. argyraea is an easy-to-grow species, found in the dry alkaline sandy soils of Texas and New Mexico. Here at JLBG, it has thrived everywhere it’s been planted…all dry, un-irrigated beds. Native pollinators love it also.
Late summer/early fall is show season for Eryngium aquaticum var. ravenelii…a superb southeast native plant that’s almost unknown by native plant enthusiasts. In the wild, it grows in seasonally flooded ditches, but in the garden at JLBG, our plants thrive in typical garden soil with an average amount of moisture. Here are our plants flowering now…each filled with an array of pollinators.
The Pipevine Swallowtail butterfly caterpillars are munching away on any aristolochia (pipevine) in sight. This week, their favorite in the garden is the stunning Aristolochia fimbriata. Nature has created a wonderful balance where the catepillars each just enough to survive and grow, but not enough to damage the plant, which will quickly re-flush.
Flowering at JLBG this month is one of our favorite small trees, Cyrilla racemiflora…aka: swamp titi. Cyrilla racemiflora was a favorite tree of the late J.C. Raulston, who was constantly extolling its virtues to anyone who would listen. Swamp titi has a native range from coastal Delaware south and west to East Texas. The flowers, which have just recently started here are a favorite of the native bumblebees. Mature size is usually 10-12′ in height, and the contorted nature of the trunks usually produce a plant that is slightly wider than it is tall. Despite its southern origins in swamps, Cyrilla is well adapted to regular garden soils as far north as Zone 5. As far as the common name, we have no idea where “titi” originated. We’ve read theories that it may have been a corruption of TyTy, Georgia, or have some relation to Florida’s Titi Creek, but those are all unconfirmed.
We’ve got a different take on going tubing. For us, tubing is something we do, starting in mid-June each summer, when we sit and enjoy our patch of Sinningia tubiflora. This amazing South American (Argentina, Uruguay, and Paraguay) gesneriad (African violet cousin) forms masses of underground potato-like tubers, which produce these amazing stalks of sweetly fragrant flowers for months each summer. These are reportedly pollinated by sphinx months. Sinningia tubiflora is insanely drought resistant and so easy to grow if given enough sun. Since it forms a large mass, don’t plant it near smaller, less-aggressive neighbors.
Turn your garden into a pollinator’s paradise with a progression of blooms throughout the seasons.
Learn more about the fantastic relationships between plants and their pollinators during our upcoming pollinators class with nursery manager, Meghan Fidler, Saturday, August 17, 10am-noon.