Friday, September 5, 2014

Love the Lemony Blooms on this Bottle Brush

Nearly one month ago, a colleague and I were watering in the order beds.  It was the height of summer and London was suffering from droughty conditions.  I think that both of us were starting to get pretty exhausted from lugging hoses and sprinklers around.  When my co-worker called to me from further down the row, my stomach sank.  I thought maybe I had inadvertently squashed something with my hose.  But he was only calling my attention to a mildly attractive shrub. 

Callistemon pallidus is a shrub to get
excited about when it's in bloom
"This is a really interesting plant," he said, "It has an unusual flower."  Callistemon pallidus (2010-117) wasn't in bloom yet, and after a further description of the blooms, I shrugged my shoulders and went back to work.  I've seen a Callistemon (a.k.a. bottlebrush) before.  I wasn't particularly impressed.

Last week, the mildly attractive shrub opened one lemon yellow bottlebrush flower.  I was hooked.  It held that solitary bloom for seven days before sputtering out several more.  It's a "must see" for anyone who is a fan of  interesting shrubbery.  I know there's a few of us out there.

Callistemon pallidus, or the lemon bottlebrush, is native to Tasmania, Victoria, and New South Wales in Australia.  The specimen in Kew's order beds was grown from wild material in its native habitat.  The notes in Kew's living collections database state that there were about 500 or less plants growing in a Eucalyptus forest, alongside Billardiera longiflora, Leptospermum, Banksia marginata, and Lomatia tinctoria.

Like other Callistemon, lemon bottlebrush does not tolerate cold.  Its USDA hardiness zones are 10 and 11, which rules out Knoxville, Tennessee unless we overwinter in a protected environment.  However, gardeners in California, Florida, and similar climates who are a bit sick of the typical lipstick red bottlebrushes should consider substituting this lemon beauty.

Kew's specimen was planted in 2010,
so it is still relatively young.  It may
reach up to 12 feet in height!
C. pallidus can get up to 12 feet tall, so consider placing toward the back of a border, the center of a bed, or as a barrier or hedge.  If red spider mites are common in your area, the lemon bottlebrush may not be right for you.  Check to see how the other Callistemon in your neighbourhood are performing before adding the lemon bottlebrush to your landscape.

If you're in the London area, come to Kew and have a gander at the specimen growing in the order beds.  If you live in a warm climate, consider adding this plant to your palette.  The rest of us will have to settle for using as a container plant and moving to the garage for winter.  I think this bottlebrush is well worth the effort.

If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

To see more photos from this week, be sure to check out the album "Love the Lemony Blooms on this Bottle Brush" on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.

  • "Callistemon pallidus".  (21 May 2013).  Australian National Botanic Garden.
  • Center for the International Trade in Endangered Species database
  • Kew's Living Collections database
  • The International Union for Conservation of Nature and Natural Resources Red List of threatened species
  • The Plant List website
  • The Royal Botanic Gardens, Kew website and staff

Sunday, August 31, 2014

Hop hornbeam makes me happy

At the end of my first week at Kew, all the interns were taken to the library.  As Daisy and I walked toward the entrance of the building, one tree stopped me in my tracks.  The tree was completely draped with lacey white clusters of seed pods.  "What is that tree?" I asked Daisy, assuming it was an English native.  She didn't know, but I kept my eyes peeled for another specimen with a label.

Beautiful, showy seed clusters of Ostrya virginiana
resemble hops, thus the common name "hop hornbeam"
Later that summer I noticed another specimen growing in Kew's Duke's Garden.  The label identified it as Ostrya virginiana (1973-14189), more commonly known as ironwood or the hop hornbeam.  Imagine my surprise to learn that this tree is native to my region of North America, and then some.  Hardy to USDA zones 3 to 9, its range spreads as far north as Prince Edward Island and Manitoba, westward to the Dakotas, and as far south as Honduras. 

What the hop hornbeam lacks in flower luster, it makes up for in seed.  The green catkins aren't really that noticeable or attractive, but the seed pod clusters are very attractive and persistent.  These clusters resemble hops, which earn the common name "hop hornbeam".  The specimens at Kew have held their clusters from at least the last week of June until present.  The seed pods were a brilliant white at the end of June, fading to salmon, now with tinges of brown.  The seeds are a food source for wildlife including birds and small mammals.

View of the attractive clusters
from inside the tree
Although the tree is stunning in seed, it is also attractive in foliage.  The shiny green leaves resemble an elm or birch.  Fall foliage is yellow.  I've seen specimens with a very fine, gold fall color that persists for several days.  The autumn show may not be dependable and will vary by the environmental conditions.  According to the Missouri Botanical Garden plant finder website, "Leaves turn an undistinguished yellow in autumn and often drop early."

Ostrya virginiana is a slow growing, medium sized tree.  In most regions within its range, this tree won't get taller than about 40 feet.  There may be some exceptions, such as the 73 feet tall by 88 feet wide specimen discovered in Michigan in 1976.  But achieving such heights would take a great deal of time.  Its slow growth results in very dense, hard wood (thus the common name "ironwood").  However, this feature is not of much economic value because it would take such a long time for a stand to yield any harvest worthwhile value.  

Yet the slow growth, small stature, and strong wood makes this tree a valuable addition to a residential or commercial landscape situation.  Businesses and homeowners should consider substituting this underused strong, healthy native for the more common pest and disease prone Cornus florida or extremely weak-wooded and invasive exotic Pyrus calleryana 'Bradford'.

Despite the great potential for cultivating Ostrya virginiana in the urban environment, it has been classified as a "weed" by those who cultivate timber crops in some regions.  To quote a USDA Forestry report from 1990:

Attractive foliage
The slow growth and small size of the species earn it the title "weed" throughout its range, especially in some areas in the South where it is considered the number one weed species. Eastern hophornbeam usually is discriminated against in stands managed for timber. Silviculturally, more interest has been given to eradicating it than to improving its growth.

Perhaps the hop hornbeam is a bit weedy in stands of timber because it is so adaptable.  Ostrya virginiana has been found in soils that have acidity levels between 4.2 and 7.6 pH, and growing in elevations between 250 feet and 5,000 feet.  The hop hornbeam is also very pest and disease resistant, with few recorded issues.  One thing this tree won't forgive is wet feet.  In the wild, it is common in dry stream beds, bluffs, and even xeric conditions. 

Fall is approaching, and the upcoming cool season is a fantastic time to add woody trees and shrubs to any landscape (learn more by reading the tree planting post).  When considering what specimens do add to your garden, be sure to add the adaptable and beautiful Ostrya virginiana to the list. 

If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

To see more photos from this week, be sure to check out the album "Hop hornbeam makes me happy" on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

Nice, open habit
Shaggy, peeling red bark
All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.

  • Center for the International Trade in Endangered Species database
  • "Ironwood or Hop Hornbeam".  N.D. Tree Handbook.  North Dakota State University.
  • Kew's Living Collections database
  • Metzger, N.F.  (1990).  "Eastern Hop Hornbeam".  Silvics of North America, Volume 2: Hardwoods.  United States Department of Agriculture Forest Service.
  • "Ostrya virginiana".  Missouri Botanical Garden Plant Finder. 
  • The International Union for Conservation of Nature and Natural Resources Red List of threatened species
  • The Plant List website
  • The Royal Botanic Gardens, Kew website and staff

Tuesday, August 26, 2014

Hosta Heavens

You don't need to be in horticulture long before discovering certain plants that seem to naturally attract a following of enthusiasts.  Actually, this phenomenon was the subject of one of my very first blog posts.  The genus Hosta with its plethora of species, hybrids and cultivars is definitely one of those magnetic groups of plants.  Although I'm not as keen as some hosta fans, I certainly enjoy them enough to warrant spotlighting this genus as the plant of this week.

Hosta collections, like John & June's
"Hanging Hosta Gardens", showcase an
array of these versatile perennials (HHG)
What's a Hosta?
Hosta are herbaceous perennials that are currently listed as members of the lily (Liliaceae) family.  However, recent studies in cell morphology (cytology) suggests that hosta and agave are distant relatives, which has sparked the question as to whether the genus should be placed in the Agavaceae family instead.  Some sources also list hosta as in the asparagus (Asparagaceae) family.

Attractive clumps of foliage spring forth from clumps of shallow, fleshy rhizomes.  Hosta may be bred for foliage, flower, or growing requirements (particularly sun tolerance).  The sky seems to be the limit on the diversity of plants that come from some breeding programs.  Here are just a few examples.

The colors of hosta foliage ranges from a deep, waxy blue up to a pale, delicate yellow.  Leaves may be solid or they may have two or more colors.  Many varieties have a lighter margin, although some have attractive streaked foliage (H. 'Stained Glass').  Leaves may be violently linear (H. 'Hands Up') or more rounded (H. 'Blue Mouse Ears').  However, the shape is typically more attenuate, like that of a plantain.  Thus the common name "plantain lily".  Although the leaves are usually more smooth to the touch or lightly textured, there are some varieties that have deep veins that give the foliage a bubbled appearance (H. 'Crumples').  

There is also a huge variety in foliage size.  The smallest hostas fall into the 'tiny' category.  Tinys must produce leaves that are smaller than 2.5 square inches.  'Mini' hostas are one class larger than tinys.  Their leaf area should be smaller than 6 square inches, and they typically produce clumps that are between five and nine inches wide.  In practice, however, mini varieties have been known to exceed their class size depending on the environmental conditions.  On the opposite side of the spectrum are giant hostas.  'Very large' hostas should have a leaf area that is greater than 36 square inches, and the clumps may be 36 inches wide.  Wow!

Miniature hostas, like those in Jonathan
Hogarth's National collection, have leaves
that are smaller than 6 square inches (JH)
Hostas produce racemes of delicate, bell-shaped flowers that have a lovely fragrance.   Flower color is usually violet, although this ranges from deep purples to nearly white.  As is true for other plants that are bred for foliage (Heuchera) or unusual flowers (Echinacea) the fragrance may have been more or less bred out of many popular hosta varieties.  If you're looking for a fragrant hosta, be sure that feature is listed on the plant description before buying.

Many people in the industry associate hostas with shade.  There may be unfortunate consequences if some varieties are exposed to sunshine.  Blue varieties may lose their waxy covering, and some lighter groups may simply burn.  However, there are quite a few hostas out there that can hold their own in the sun.  These varieties seem to tend to have a thicker leaves that are green or lighter in color.

A brief history
Hostas native range is through northeast Asia, including Japan, Korea, and areas of China.  The evolutionary history of hosta is quite fascinating, and well worth a looking into if you're interested in learning more about the complicated past of this genus.  The ancestors of some popular new hybrids actually cling to rock faces in Japan.  You can spot the descendants by looking out for plants that have a red stem and leaves that are white underneath.  Collector June Colley informed me this white underside helped protect the plants from sun damage by reflecting light from the rock surfaces below.

Some hostas from Japan have a white
cast to the bottom of their leaves (JH)
The first Westerner to botanically describe hosta was Englebert Kaempfer as part of a survey with the Dutch East India Company.  One source provides his descriptions for the two hosta spotted on this trip as "vulgo gibbooshi Gladiolus Plantagenis folio (meaning 'the common hosta with the plantain-like leaves')" and "Gibbooshi altera (meaning 'the other hosta')".  Obviously this was a time before the Linnean style of binomial nomenclature was enforced.

When these plants were switched to the binomial system, they were renamed Aletris japonica.  Shortly thereafter in 1784, hosta were assigned the genus Hemerocallis.  If the name sounds familiar, it's because that's the genus for daylily.  Since both hosta and daylilies had a somewhat similar clumping growth habit, tufts of basal foliage that dies back in the winter, and were both in the lily family, they were considered the same genus for some time.  Although they were given their own genus Hosta in 1812, groups like the BritishHemerocallis and Hosta Society continue to celebrate both genera in one society.

Tips for growing
Annelids like slugs and snails are frequently
problematic for many hosta growers
    One things that I've noticed about plants that elicit large followings, such as orchids, dwarf conifers, and hosta, is that they all have their growing quirks.  It's certainly not always easy to grow an orchid, and the same is true of hosta.  

    The large patch of H. 'Guacamole' (or at least that's what Walmart had them labelled as in the discount bin...  I have my doubts...) that I planted under a dogwood in our front yard in Knoxville, Tennessee does fine on its own, with little maintenance or attention required.  Yet the plugs of H. 'Blue Mouse Ears' that I kept in concrete containers by the front door didn't fare so well.  

    Success will vary depending on the type of hosta and the environmental conditions.  Here are my top three for growing hosta .

    Consider displaying your hostas
    in containers.  Hanging baskets
    can give a fresh perspective on this
    familiar perennial. (HHG)
    1. Don't over-mulch!  This is true for many clumping perennials.  Although mulch is a fantastic way to conserve water and deter weed growth, too much of a good thing can be a bad thing.  Thick layers of mulch can "collar" the plant, burn the crown, promote rot, ... the list goes on.  Just remember to keep an eye out.
    2. Annihilate Annelids.  Okay, that seems a bit harsh, but slugs and snails can be extremely destructive pests on hosta -- especially in the U.K.  For example, Kew doesn't treat hostas for annelids, so the foliage of most of the specimens are tattered and full of holes.  This is just not attractive on a plant that is valued for its foliage.  There are loads of folk remedies out there, including leaving a glass of beer out, putting a copper ring around the plant, adding a ring of diatomaceous earth, etc.  Gardening is an experiment, and enthusiasts will take the time to find the right solution for their situation.   For example, avid collectors John and June interplant their collection with pokeweed (Phytolacca americana).  June is currently researching whether the saponin content of the pokeweed deters slugs and snails.  Jonathan Hogarth, another hosta fan, adds a layer of sharp rocks to the top off all his hosta containers.  "The slugs don't like to cross it," he said, "although some do get through occasionally."  Another alternative would be planting slug resistant plants.  The thicker the leaf, the more resistant the plant tends to be.  Another collector, Tennessee's own Cornelia Holland, informed me about the exciting new (relatively) slug resistant Tardiana series.
    3. Consider a Container.  I was fortunate enough to see some really spectacular hosta collections over the weekend, and all the plants were in containers!  Leaving your plants in containers gives you a bit more control over the health of your plant.  Too bright and sunny?  Just move the pot.  Need to overwinter a tender specimen?  Move the pot to the garage.  What’s more is that many hostas will naturally drape over the edge of the pot.  John and June’s collection was so full and dense that I frequently forgot that all the plants were in containers!  Placing containers at or above eye level can also give a fresh perspective.  

    Hosta heavens
    In celebration of the really fantastic collections I was able to visit this weekend, I thought I’d wrap up this week’s post with a brief list of some neat hosta gardens that I’ve come into contact with.  The list is organized in autobiographical order.

    Any Knoxvillians who have a hankering to see some massive, gigantic hostas should head to the KMA this fall before the plants go dormant.  The hostas in their courtyard are easily the biggest ones I’ve ever seen.  Definitely worth a gander.

    Jonathan Hogarth's fantastic hosta
    collection, displayed in the British style
    where the foliage is allowed to overlap
    Although I’ve never been to avid collector Cornelia Holland’s garden, I’ve heard many fantastic things about it.  As of 2012, she had 900 species in her collection, which warranted a stop on the American Hosta Society’s National Convention in 2012.  I’ve seen photos of Tranquility online and in departmental seminars at the University of Tennessee, Knoxville. A month or so ago, Dr. Susan Hamilton, the director of the UT Gardens, put me in contact with Ms. Holland to learn more about meeting her fellow hosta enthusiasts while I’m in the London area.  In no time at all she had me on track for what would be really inspiring tours.

    Next on the horizon for the UT Gardens is a world-class hosta collection, both for aesthetics and scientific discovery.  Stay tuned to their website for more information as it becomes available!

    Jonathan Hogarth’s Collection
    Mr. Hogarth not only obliged to let me come visit his miniature hosta collection, but he also planned my whole hosta day (Thanks!!!).  We almost got in a tour of His Royal Highness, Charles the Prince of Wales’ (patron of the British Hosta and Hemerocallis Society) hosta collection, but it was not to be.  My first stop was Mr. Hogarth’s for some tea and coffee, then hosta viewing.  The hostas are grown in containers all around the garden, with many growing on shelves mounted on fences.  I learned the history of the collection, loads of fun facts about the plants (a small fraction of which is contained in this post), the requirements for an official hosta collection, and got lots of inspirational ideas that I can’t wait to try at home.

    John and June of the BHHS generously opened their gardens a tour, and the display was really brilliant.  All the plants are in their own individual pots, but you wouldn’t know since the arrangements are so dense.  Although the hosta collection is at the forefront, other herbaceous perennials, annuals, and woody specimens are sprinkled in as well.  The display changes with the season.  If we had been there a month or two earlier, we would have seen a riot of Hemerocallis in bloom.  But there wasn’t a hint of daylily foliage this weekend – they’d been moved to grow on happily in a quiet, out-of-the-way location.  But one of the most interesting displays was definitely the hanging hostas.  Pots of hosta were pinned up against walls, fences, and hung from posts all over the property.  It was a totally different way of viewing hostas – from below rather than above!

    John and June's front garden includes a great deal of hostas at this time of year.  All the plants are grown in containers, and the display changes with the seasons.  Wow!
    If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

    To see more photos from this week, be sure to check out the album "Hosta Heavens" on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

    All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.


    Monday, August 11, 2014

    Mixed Feelings for Eucalyptus dalrympleana

    I try to start these blog posts with some kind of catchy reason why you should love the plant being profiled.  When it comes to Eucalyptus dalrympleana (USDA hardiness zones 8 to 11), there are just too many reasons to pick just one.  So instead of my normal format, this whole post will support the following reasons to love (or hate) this beautiful Euc.

    E. dalrympleana has showy, vanilla
    scented blooms that can be messy
    Reason #1, Love: Its flowers smell like vanilla / Hate: The flowers also make a huge mess

    In its native range of southwest Australia, Eucalyptus dalrympleana blooms through late summer.  At Kew, our specimens burst into flower in early August, and the blossoms linger through to September.  This species of Eucalyptus usually has clusters of three flowers, but some specimens from the northern tableland may have clusters of as many as seven flowers.

    Although the very frilly blooms fall to bits and make a giant mess below the tree, I think that's a flaw worth forgiving.  The burden of sweeping the pathways at least one day a week is lightened if you can pause to enjoy being enveloped in their soft vanilla scent.

    Reason #2, Love: Its leaves smell like cinnamon / Hate: It is constantly shedding leaves

    Although many of the most familiar species of Eucalyptus have a soft blue cast to their leaves, E. dalrympleana has shining green foliage.  The attractive green foliage makes this plant a bit easier to place in the landscape than the more striking, blue-leaved Eucs.  When crushed, the leaves smell strongly of cinnamon.

    Fruit and foliage of E. dalrympleana
    The mountain gum near Kew's aquatic garden has been dropping leaves the whole time that I've been here.  Daisy and I usually have to rake them up at least once a week.  Some weeks Jim the volunteer has to rake them up too.  It's frustrating to think of the other things we could be doing with our time if this tree would just take a break.  However, this tree is easy to forgive because raking doesn't always take too terribly long, and when you step on or rake up the brown, dead leaves everything smells like cinnamon.

    Reason #3, Love: In August, it makes the whole area smell like pumpkin pie / Hate: In August, you may have some "hay fever"

    I know that so many other foods besides pumpkin pie contain both vanilla and cinnamon, but for some reason this tree just smells like pumpkin pie.  The week that the flowers really started to come in, Jim, Daisy and I were working around the trees at the aquatic garden.  Jim casually asked if I'd ever had pumpkin pie.  "Of course I have," I replied, "We have it every Thanksgiving."

    This Eucalyptus is especially floriferous in August
    He went on to casually mention that the last intern from the U.S. brought in a homemade pumpkin pie, and that he'd really enjoyed it.  At first I thought he was fishing for some pie (he may well have been), but when time passed and I couldn't shake a hankering for pumpkin pie, I realized that the tree was responsible for his comments.  Probably 100 feet all around these trees smelled strongly of the dessert.  Who could help but reminisce about pie when the spot you've been working for the past few hours smells so delicious?

    Although I do love the smell of sweet pumpkin pie while I work, this plant has also been giving me some irritating allergies (or as they say in the U.K., "hay fever").  The overload of pollen has been giving me itchy, runny eyes, the sniffles, and some sinus pressure.  It hasn't stopped me from going out of my way to walk through the flowers on my way to the lockers yet though.

    Really beautiful, but constantly
    shedding, bark

    Reason #4, Love: Its peeling, snow white and cinnamon bark / Hate: It is constantly shedding bark

    Although the flowers and scent are nice, what really draws visitors up to these trees is the incredibly attractive bark.  Most of the surface is clean and white, but as is true with many Eucs, the bark peels.  This species will loose huge swathes of cinnamon red bark.  The bark looks really attractive while it's still on the tree.  Yet the bark is a bit irritating when it's scattered all below the tree.  We're constantly picking up chunks of bark from the lawn, paths, and raking it out of the beds below.

    Reason #5, Love: Its sinuous, twisting wood and open habit / Hate: Fear of dropping limbs

    E. dalrympleana has strong, heavy branches that are held nearly horizontally from the trunk.  This feature gives the trees a very open, savanna-like feel.  It also can be quite dangerous.

    View from the inside of this mountain gum
    One windy day, while I was intently trying to snap a clear shot of the flowers for this post, a visitor ambled up beside me.  "We call this tree the widdah-makah," said a young man with a thick Australian accent.  I didn't quite understand what he was saying at first, but I guess they call this tree the "widow maker" where he's from.  He explained that although the habit is beautiful, it's also a deadly combination.  Extremely heavy wood held at such an angle is prone to drop without much warning.  A heavy limb from up to 120 feet overhead can kill a person.  Thus the nickname.  "Men would go into the bush, but they wouldn't come back."

    Kew's arborists keep an eye on this specimen, along with all the other trees on the property.  If you look up into the canopy, you can see the measures they have taken to prevent any falling limbs.  They remove any branches that they decide are dangerous, and they even tie supports to hold up the limbs that they suspect may fall.  Homeowners should avoid planting these trees in heavily populated areas and consult with an arborist for regular maintenance.

    Reason #6, Love: Its sap looks like red spaghetti / Hate: Its sap will stain any pavement below the tree

    Although the wound has nearly healed, you can
    spot the red strands of sap eeking out of the cut
    If you prune any tree, the wound will drip with sap until it begins to heal.  In my experience, the cut usually looks a bit damp for a bit, then dries up.  The sap of E. dalrympleana doesn't behave like any other sap I've seen before.  When it eeks from a wound, it comes out in thick, long, spaghetti-like strips.  The sap is a brilliant red, which makes the wounds quite showy.

    Although this looks really very interesting, the sap does fall eventually.  If it falls on a pathway below, the sap can stain the pathway with red, sticky dots.

    This tree is beautiful, adaptable, easy to love for all of its virtuous and even easier to forgive for all of its failings.  That is why this attractive Eucalyptus would make a valuable addition to any large garden or landscape.

    If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

    To see more photos from this week, be sure to check out the album "Mixed feelings for this Eucalyptus" on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

    All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.

    • Center for the International Trade in Endangered Species database
    • Kelly, S.; Chippendale, G.M.; Johnson, R.D.  (1969).  Eucalypts.  Melbourne: Thomas Nelson (Australia) Ltd., page 38
    • Kew's Living Collections database
    • The International Union for Conservation of Nature and Natural Resources Red List of threatened species
    • The Plant List website
    • The Royal Botanic Gardens, Kew website and staff

    Saturday, August 2, 2014

    Stipa ichu -- the other hair grass

    I've been a fan of Mexican hair grass, or Stipa tenuissima, long before I knew I wanted to be a horticulturalist.  When we teach landscape plant identification at the University of Tennessee, this Stipa always garners interest. While working in the garden, visitors would frequently stop to ask for more information about this hair grass.  And who can blame us?  This lovely grass forms large clumps that resemble long, fine, shining blonde hair.  It's a beautiful plant that is really popular in Tennessee landscaping.

    My new favorite Stipa
    However, in Kew's grass garden, Mexican hair grass doesn't stand out from the rest.  It sort of blends into the mass of lovely clumps of grasses.  However, one of its cousins shines out from the mounds of Miscanthus and drew my interest from day one -- Stipa ichu (2006-491, ), the Peruvian feather grass.  What's the difference?  Where S. tenuissima resembles a short mass of shining blonde hair, S. ichu looks like a much taller swathe of shimmering silver hair.  Let me put it this way -- the makers of the Harry Potter movies could have used an infloresence of S. ichu to represent unicorn hair in their magic wands, and nobody would have questioned it.

    It looks like unicorn hair

    Compare the open panicles (left) to
    the more silvery, young flower (right)
    At Kew, the silvery panicles burst from the fine, green base towards the end of June.  They really shimmer in the morning sun.  These infloresences begin to open and fluff out through July, losing a bit of the silver and becoming more white and a little less reflective.  The open panicles are much lighter, and they get caught up in the wind much more easily.  It's really something to see this plant on a breezy day.  The clumps look like they're dancing with each other.

    The silky flowers can also be tawny, white, or purple, and they can grow over a foot tall.  These flowers are held on a plant that could ultimately get 4 feet tall.  The base of the plant is a clump of fine, sturdy, green foliage (Hitchcock, 398).

    Native to the Americas

    As with its cousin, S. ichu covers a large range over North and South America.  You may find this silvery hair grass in the hills of Mexico, in the plains of Argentina, and even growing up in the heights of the Andes mountains.  In Hitchcock's monograph of the grasses of South America, he noted that S. ichu was fairly common in the upper altitudes of the Andes.  In the introduction, he described the area:

    "Most of the region is mountainous, the Andes transversing it from north to south.  Although lying under the Equator, much of the region is so high an elevation that many ranges and peaks are capped with perpetual snow." (Hitchcock, 6)

    S. ichu was first botanically described in 1798 from Peru as Javara ichu.  Traditionally Peruvians used "ichu grass" for thatching their homes and other structures (Hitchcock, 398).  The fact that this plant will thrive in the warm, dry, arid plains of Mexico up to snowy peaks m Peru means that it is tough and adaptable.  There is no indication that this plant is in danger of extinction in its natural habitat today, either from the CITES database or the IUCN Red List of threatened species.

    Landscape value

    This attractive and adaptable
    ornamental grass deserves
    a spot in any landscape
    This is definitely an interesting, eye catching plant that deserves a spot in your garden.  When a group of plant sciences and landscape architecture students from the University of Tennessee came to visit Kew last week, two separately and independently mentioned this plant to me in conversation.  One student said that he couldn't capture the beauty of the grass garden in a photo, so he took some video as well.  I encountered the same problem when trying to get a good photo of S. ichu, so there is a video at the bottom of this post as well.

    If you're growing at home, you'll want to give this plant a bit of space.  When planted in an area that is exposed to wind, it kind of whips around and could knock into its neighbors (see video).  Although this silvery grass would make an interesting focal point, it would really shine out en masse.  Consider planting Ajuga 'Black Scallops' as a neighboring ground cover to serve as as a dark foil to this shimmering Stipa.

    If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

    To see more photos from this week, be sure to check out the album "They should call it 'unicorn hair grass'" on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

    This eye catching grass really stands out from the crowd

    All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.


    Friday, August 1, 2014

    These flowers look like Princess Jasmine's slippers

    There are pretty flowers, there are beautiful flowers, and there are magnificent flowers.  This post is about a magnificent flower - jade vine, or Strongylodon macrobotrys (1963-72801).

    "Eye catching" doesn't do it justice

    The showy blooms of jade vine
    are definitely worth making a trip
    to a larger botanic garden to see
    Like I said, the flowers are the feature that first caught my eye.  My co-hort Nathan and I had spent hours exploring the Fairchild Tropical Botanic Garden in the sweltering Miami heat.  Towards the end of the adventure, just as my enthusiasm was waning, I saw a glimmer of jade from a pergola in the distance.  My slow, tired trudge transformed into a quick step as I hastened to the tropical vine pergola.

    The whole structure was draped with these really spectacular teal racemes.  Apparently each floral spray can grow to around 4 feet!  The individual blossoms that adorn each raceme look like they could be shoes for a Princess Jasmine doll.  They're violently teal, just like the Disney princess' outfit in Aladdin. Although the flowers are borne on a long raceme, they're not very large.  A flower may be about 6 cm in length.

    And this isn't necessarily a brief show of blossoms.  According to the manual Flowering Plants and Ferns of Mt. Makiling, the jade vine will flower from January to June, and again from November to December in its natural habitat.  That's quite a long blooming period!

    Gargantuan fruits

    Given the somewhat dainty nature of the flowers ("dainty" is not the right word, but I can't think of a better one), I was absolutely floored by the massive size of the fruits when I first saw them in Kew's Princess of Wales Conservatory.  They're like mangoes!  Is it any surprise that out of all the fiddly flowers that bloom, only one or two fruits develop? 

    The showy blooms of jade vine
    are definitely worth making a trip
    to a larger botanic garden to see
    In the wild, Strongylodon are pollinated by bats.  That's not feasible for plants grown in conservatories, such as Kew's Princess of Wales or Palm House.  However, rather than forgoing hope for developing these huge fruits, Kew practices hand pollination.  When Nick from Kew was giving the interns a tour of the Princess of Wales Conservatory, I asked about the contents of his tool belt.  Sure enough, he had a small paintbrush that he uses to pollinate flowers like the jade vine. 

    Fun fact -- you can actually track some of the maintenance details of specific plants in Kew's living collections database.  This exact plant was successfully hand pollinated by Simon Creed in 2013.  Simon pollinated the flowers at the end of March, and the seed was ready for collection the first week of May that year.  For those of you who haven't been following NEW at Kew, Simon is a young horticulturalist who just graduated from Kew's apprenticeship program on Friday.  Congratulations Simon!

    If you've only seen the flowers, it's worth making a second visit to see this plant in fruit.  Depending on various factors, there should be fruit around this time of year.  In its native range, jade vine fruits in May and September.  It doesn't seem to follow that set schedule in cultivation.  Kew's specimen has some large fruits right now.

    Is it from outer space?

    The fruits are really something to
    marvel at as well
    I have trouble wrapping my head around the idea that these splendiferous flowers are naturally occurring someplace on this planet.  However this species is native to the Luzon and Mindoro islands in the Phillipines.  You'll find their teal blooms draped from vines that are clinging to the steep slopes of Mt. Makling, up to 1,000 meters up in altitude.  This mountain is actually a volcanic mountain, although it hasn't erupted in recorded history, or at least since the 16th century.  The mountain rises from the Laguna de Bay on Luzon Island.

    As you may have read in the previous few posts, this plant is not listed as endangered or threatened by the CITES database or IUCN red list.  However, Kew's living collection database states that this species was on the IUCN red list of endangered species in 1997.  I wonder whether this plant has made a recovery in the wild, or if there is a problem with their website.

    Appreciating this plant

    This is not a small plant.  Unless you
    live in a tropical climate, it would
    be best to appreciate at a botanic garden.
    This tropical plant has a USDA hardiness zone rating of 10 to 11.  This means that unless you live in a tropical climate like Miami, it isn't really feasible to grow Strongylodon as a landscape plant.  Some enthusiasts may be tempted to grow as an interior plant, but that wouldn't be practical either.  Remember, the jade vine is native to the warm, humid cliff faces and river banks of the Philippines.  If your house isn't tropical, this plant won't be happy to grow there.  Also, it would just be too big to keep inside. 

    Rather than growing at home, I recommend interested parties to visit a botanic garden that has a conservatory.  If you live in a small city, your local public garden may not have this plant (or a conservatory), but seeing this plant in bloom makes the journey to a large garden, like Kew,  Fairchild or Missouri Botanic, totally worthwhile.  Check with the garden first to make sure that it is in flower or fruit.  I can attest that seeing this magnificent plant in full bloom is worth the trip!

    If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

    To see more photos from this week, be sure to check out the album "A Whole New World with Jade Vine" on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

    All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.

    • Center for the International Trade in Endangered Species database
    • Fernandon, E.S.; Sun, B.Y.; Suh, M.H.; Kong, H.Y.; Koh, H.S. (2005).  Flowering Plants and Ferns of Mt Makiling.
    • Kew's Living Collections database
    • Pancho, J.V. (1983).  Vascular Flora of Mountain Makiling and Vicinity (Luzon: Philippines) part 2.
    • The International Union for Conservation of Nature and Natural Resources Red List of threatened species
    • The Plant List website
    • The Royal Botanic Gardens, Kew website and staff

    Monday, July 21, 2014

    The flower that makes me crave fried eggs

    The 4 inch flowers of Romneya
     look like a fried egg
    cooked sunny-side up
    Believe it or not, I actually had a very difficult time picking a plant to cover this week.  I knew that somewhere in Kew's 300 acres I should be able to find one plant that I find genuinely interesting, but inspiration never struck.  My group spent a couple days working in the Secluded Garden this week, and while we were working I kept running through plants in my mind, nixing some and earmarking others for later.

    While I toiled away in mental anguish, visitors kept interrupting my train of thought to ask, "Excuse me please, what is the name of that plant?"  "What is that plant?"  "What do you call that plant?  That one on the other side of the water?"  Each group was asking about the same plant -- a large, shrubby poppy that was covered in white blooms growing just on the other side of the stream (1994-3738, SCON).  Nobody could seem to remember the genus, so every time someone would have to scurry down the embankment, ford the waters, and call back, "Romneya coulteri -- It's a kind of a poppy."

    Finally, after four or five times, I thought to myself, "This may be a plant worth writing about."  And I wasn't disappointed.

    Back to its roots

    Romneya coulteri, or the canyon matilija poppy, is native to southern California.  Its range includes Los Angeles, Riverside, Ontario, and San Diego counties.  R. coulteri is perennial from USDA hardiness zones 7 to 11.  It thrives in chaparral and coastal shrub habitats -- especially in dry washes and canyons where the altitude is less than 1,200 meters (Hickman, 816). 

    Seed head of R. coulteri.  The seeds of
    this species of poppy actually
    have a higher germination rate when
    exposed to smoke caused by a fire
    The matilija poppy may also be spotted in areas that have been affected by fire.  R. coulteri has adapted to fire damage in two ways.  First, shoots will easily re-sprout from the roots after the plant is burnt to the ground.  Second, exposure to smoke can actually increase seed germination (California, 239). 

    This California native was first noted by a European in Baja during the early 1800's.  T. Romney Robinson was an Irish astronomer who had an eye for beauty in the sky and on the ground.  The genus was named Romneya in recognition of his discovery (Hickman, 816).

    Today, the habitat of R. coulteri is threatened by urbanization, including new home and shop developments, roadside expansion, and flood control (California, 239). Both Kew's living collection database and the California Native Plant Society note that this is a rare plant in need of conservation.  The notes in Kew's database for both of their specimens of R. coulteri indicate that in 1997 this species was listed as endangered by the IUCN red list.  However, neither the CITES database nor the IUCN red list currently list it as endangered.

    It looks like a fried egg

    Just like all of our curious visitors, the feature of this plant that really stands out to me are the white and yellow blossoms.  Their 4 inch blooms look just like a fried egg cooked sunny-side up.  This species actually produces the largest flowers out of any of California's native plants.  That is especially compelling when you consider that the state of California is over 400,000 square kilometers and covers twenty-one distinct (and often wildly different) types of landscapes.

    R. coulteri in the Papaveraceae section of the
    Chelsea Physic Garden.  Notice how much taller
    it is than the other poppies in the bed.
    R. coulteri in cultivation is really floriferous.  I saw two specimens of the matilija poppy at Kew (2004-2746, PERH) and one at the Chelsea Physic Garden, and they were all totally laden with flowers. You can count on this plant flowering non-stop through the whole summer, from as early as May right up until the end of July.  The foliage is a very attractive soft, silvery blue.  Although the leaves vary in length, the deep lobes and cool color really softens the effect of the sunny blooms.

    If you're picturing these flowers held on a plant that resembles other poppies, think again.  This is a big plant -- another common name for R. coulteri is tree poppy.  It isn't uncommon for the matilija poppy to grow upwards of 6 feet (2 meters) tall.  I haven't read anything on this, but I'd be interested to learn whether the plant sets flower buds on old or new growth.  This would dictate how you should prune to maintain size.  If it sets flowers on old growth, then all old stems that have already bloomed should be removed at the end of the growing season.  If it blooms on new wood, then it should be cut back hard to about 6 inches after the danger of frost has passed in the spring.  Or you could embrace this plant at its natural height and site accordingly.

    Landscape value

    Although the matilija poppy is native
    to dry and sunny southern
    California, it thrives in more cool,
    moist and shady conditions
    Although R. coulteri is native to a hot, dry Mediterranean type of climate, the plant is very adaptable in cultivation.  There's a specimen at Kew that is absolutely thriving in afternoon shade and relatively rich soil.  However, the matilija poppy may be more vigorous in environments that are similar to its native habitat, including the Mediterranean and areas in Africa, Australia, and so on.  It has been described as having weedy tendencies in southern California, so gardeners in similar climates have a responsibility to keep an eye on their specimens and report any invasive qualities.

    The matilija poppy is at home towards the back of the flower border, where it is less likely to cover up smaller growing companions.  This plant doesn't have a lot of winter interest, so consider siting next to an evergreen, an ornamental grass, or a tree with interesting bark.  I think this plant would be the perfect fit for growing beneath a kitchen window.  The sunny blooms would really brighten the view and give a friendly reminder to enjoy a fried egg sunny-side up once in a while.

     A bit after posting this plant profile, my new friend Ann in Australia sent some helpful information that I wanted to be sure to share with you.  Thanks for sharing Ann!

    "I live in the Lower Blue Mountains west of Sydney, New South Wales, Australia.  We have very hot, dry but humid summers. (Heat zone 4, cold zone 10). Recently up to 46 C. I planted my Romneya about 10 years ago in my front garden,  in a dry westerly aspect  in full sun, on a slope with good drainage. It is tall (about 2 to 2.5metres high) with lanky canes and flowers on new growth which I cut back in late autumn to about 15cm. It will sucker by sending out underground rhizomes several metres away  and also sets seed once the plant is established. It has beautiful crepe paper thin wrinkled petals of pure white & a large raised centre of golden stamens heavily laden with pollen. The flowers measure roughly 15cm and the foliage is a smooth blue/grey. I don’t fertilise it & it relies solely on natural rainfall. The flowers are a constant delight to the bees and the shrub often “hums” with bee activity. People will often stop and ask me what this beautiful plant is when in flower."

    If you have any questions, comments or suggestions, please feel welcome to leave a comment or send me an email.

    To see more photos from this week, be sure to check out the album "The flower that makes me crave fried eggs" on the Plante on Plants Facebook page.  "Likes", shares and comments are appreciated.

    Pistil and stamen of Romneya coulteri
    This poppy is sure to stand out in any landscape.  Notice how prominent the flowers are surrounded by the other colorful selections in Kew's Duke's Garden.
    All photos and videos were taken by Amanda Plante at the Royal Botanic Gardens, Kew unless otherwise stated in the caption.

    • (1994).  California Native Plant Society's Inventory of Rare and Endangered Vascular Plants of Califoria (5th ed.).  CNPS Special Publication, p. 239
    • Center for the International Trade in Endangered Species database
    • Dave's Garden Plant Files
    • Hickman, J.C.  (1993).  The Jepson Manual: Higher Plants of California (3rd printing). Berkley, CA: University of California Press, p. 816-817.
    • Kew's Living Collections database
    • Rundel, P.W. & Gustafson, R.  (2005).  California Natural History Guides Introduction to the Plant Life of Southern California: Coast to Foothills. Berkley, CA: University of California Press, p. 101-102
    • The International Union for Conservation of Nature and Natural Resources Red List of threatened species
    • The Plant List website
    • The Royal Botanic Gardens, Kew website and staff