Perennials and Annuals – Page 7 – The Garden Professors™

Lamb’s Ears Revisited

A bit more on my recent travels to the big floriculture conference in Columbus, Ohio. I always try to make it out to the Chadwick Arboretum & Learning Gardens, on the campus of THE Ohio State University. There are several components, including trials, a large arboretum, and several small gardens. My favorite is the Steven Still Perennial Garden. It’s a lovely mixed garden, designed by Adrian Bloom (Blooms of Bressingham), and was installed in ONE DAY by their garden volunteers – 2005, I think.

Watching it grow has been fun. I noted [ with pleasure] that they’ve already had to start cutting back and removing some things. This makes me feel better because I am The Queen of Planting Too Close

A few highlights:

I thought of y’all when I saw
this…remember our conversation about Stachys the other day? Here’s a
new one on me: Stachys byzantina ‘Silky Fleece’. What teeny, tiny
little leaves! And seemed to be limiting itself to a small area on the
edge of the border. Introduced in 2006 by German seedmeisters Jelitto
Perennial Seeds. They missed the boat on naming it…could have all kind
of fun with ‘Little Lamb’ or even ‘Mary’s Little Lamb’ as the director
for their North American office is Mary Vaananen. Heh.

My foot is just in there for scale – I’m really not that inept a
photographer.

A gorgeous flock of Rhus typhina ‘Tiger Eyes’. Hardy to Zone 4, the foliage is golden in summer, blazing apricot in fall, a wonderful shrub accent in any garden… What? Hang on a sec.

Correction:
That’s Rhus typhina ‘Bailtiger’ PP16,185. Trade name is First Editions® Tiger Eyes® Cutleaf Staghorn Sumac. Well, that took all the fun out of it.

Moving on…

Belamcanda chinensis – Blackberry or Leopard
Lily. A tough cookie, this midseason bloomer takes drought and even
reseeds a little bit in my home garden. The pods burst open to
reveal a cluster of seeds that look exactly like a blackberry. These
weren’t quite that far along, but in between flowering and seed setting, they
do something else interesting..

The petals twist up into these hilarious
little bundles. I have no idea why or what for. Just kind of neat.

All for now!

What’s New?!

Just back from OFA – my discipline’s humongous tradeshow and conference in Columbus, Ohio. All things Floriculture – new perennials, annuals, and seasonal plants, technology, structures, and equipment for greenhouses, and plants and products for floral designers. The bulk of the show and educational sessions is focused on growers, but garden center owners and florists are also targeted. I was part of two team talks for growers on “Perennial Production Problems and Solutions”.

Aside from the thousands of attendees and hundreds of exhibitors, it’s like a big family reunion for floriculture faculty involved in teaching, research, and Extension. We introduce our latest graduate student to our own back-in-the-day classmates and our “old” major advisors. Beers are consumed. We’ve come to determine that we’re quite inbred; most floriculture researchers and educators received degrees and/or are employed by Michigan State, North Carolina State, Purdue, U. Florida, Cornell, or Minnesota. Many of our collegues have left academia to R&D positions in the horticultural corporate world, the conference also gives us a chance to catch up with them.

One of the highlights of OFA is the amazing array of new plant introductions from industry leaders such a Ball, Ecke, Syngenta, Dummen, Proven Winners, etc. Most of these names are not familiar to gardeners – they are wholesale (business-to-business) brands that provide growers with seeds, plugs, and liners, to be grown on and sold at retail. Proven Winners is one of the few vertically-integrated brands that market throughout the supply chain, from grower all the way to the consumer.

‘Gryphon’ – an exciting new begonia from PanAmerican Seed.

There are a slew of begonias out there – so what’s so special about this one (besides reaching almost 2′ in height and width)? Most fancy-leaf begonias are propagated by rooting vegetative cuttings that wholesale for $0.50 to $1.25 per liner. This one’s grown from seed ($0.05 per), enabling the grower to produce a beautiful plant yet still make a decent profit margin. The margin in our industry is ridiculously miniscule – wholesalers seem to constantly undervalue their product compared to all the costs involved in growing and shipping.

But I digress. I’ll post more from the “hot and new” front in ornamental plants on my next installment!

The Other Lamb’s Ears

I’m assuming even you tree people (aka other
Garden Professors) are familiar with the soft, silvery leaves of Stachys
byzantina or Lamb’s Ear (variously Lamb Ears and Lamb’s Ears). Not to
disparage S. byzantina, but in our part of the world it looks like a
pile of wet dryer lint in the winter; and can become similarly
disfigured during a hot, wet summer. Spring brings bright,
pet-able new ears, followed by woolly flower spikes that could serve as
Q-tips for Shrek. Runs/reseeds like a banshee in my home garden.
As
Dr. Allan Armitage notes, “We’ve been lamb-eared to death.”

But there are several other species of
garden-worthy Stachys, one of which is garnering lots of attention in
our campus garden at the moment. Behold, Stachys officinalis ‘Hummelo’ – Wood Betony or Alpine
Betony.

Also sold under S.
officinalis and S. densiflora. Most nurseries seemed to have settled on
S. monieri, but that specific epithet does not appear in the ITIS
(Integrated Taxonomic Information Systems) database. Armitage lists it as a cultivar
of S. officinalis and then has S. monieri as a separate species.

Regardless of pedigree, ‘Hummelo’ is a terrific perennial.
Clumps of glossy green scallop-edged foliage are topped with
spikes of rosy-lavender flowers throughout the summer. Heat- and
cold-tolerant; it’s hardy from Zones 4 to 8. Full sun or part shade,
drought tolerant, deer resistant…what’s not to like?

Back to the ubiquitous version of lamb’s ear…we
have a superior selection of S. byzantina with the fabulous cultivar
name of ‘Countess Helene von Stein’. Rarely flowers, and has bigger, tougher leaves that hang in there regardless of humidity. Very effective
when barked at students with a Teutonic accent: “Countess Helene von
Shtein! You vill learn dis plahnt!” You may find this in
the U.S. under the comparatively boring ‘Big Ears’.

Beantroversy

Castor Bean – Ricinis communis. Folks who make their living creating fabulous color displays for public gardens, municipalities, and commercial parks love ‘em. Civilian gardeners/plant geeks love ‘em. People who get their knickers in a twist about poisonous plants do not.

Pros: ridiculously rapid growth, huge leaves for that tropical look, tolerant of less-than-ideal conditions, cheap and easy to grow from seed, weird wild flowers and seed pods.

Cons: pretty darn poisonous. A few seeds (have seen figures from four to 20), chewed up to release the toxic protein ricin, will allegedly kill you. A Caster Bean seed looks like a really huge tick (head and all), which should be sufficiently repellent to anyone over ten years old. Pleh.

Beans with flowers. U.S. Botanic Garden, 2005, Washington D.C.

This topic arises because I was standing in our campus garden yesterday with said pot o’ poison (cultivar ‘Carmencita’, a red-leaf form), trying to find a place to plant it. Last summer, my department head noted them growing in front of our garden pavilion and asked that I kindly remove them. “They’re really poisonous, and kids will stick anything in their mouth, and I wouldn’t want my kids around them” (quoted best of my memory). He’s a wonderfully laid-back guy, so it struck me that he must really be concerned to bring it up. I teach Castor Bean in my Herbaceous Landscape Plants class for both the pros and the cons…heaven forbid a Hort graduate is unable to identify it, so I persuaded him into letting me keep it up if I removed the seed pods before they ripen. I’m not going to go into all the medicinal/industrial uses of castor oil (ick…I hope my generation was the last to have this foisted on us) nor the insidious uses of ricin – Google away if you’re interested.

We temperate-zone gardeners love anything tall and big-leaved to give vertical “oompf” to summer beds and container plantings. The tropical African native is considered an invasive plant throughout the subtropics; I’ve seen it in pastures and fence rows in far south Florida, the Cayman Islands and Dominican Republic. Apparently the cows and goats have learned to avoid it (natural selection?). I noticed it used en masse in the gorgeous beds lining the street in downtown St. Louis last summer, as well at several other public gardens I’ve visited over the past few years. So I’ll continue to use it in our garden’s palette of plants, but will remove the pods to keep everybody happy.

p.s. At the top of my summer reading list is Amy Stewart’s book “Wicked Plants”.

Building a Better Container, Part Deux: The Ellepot

I enjoyed Jeff’s post on the RootTrapper and thought I’d share another interesting and [relatively] new development in the world of greenhouse growing containers.

Take a tube full of growing media, wrap a paper sleeve around it, and voila – the Ellepot!

It’s bottomless, root permeable, and degradable. Each Ellepot sits in its own cell in a re-usable tray. The great aeration and drainage makes for a happy, healthy root system. Another plus is that after transplanting, there are no pots or packs to throw away

I’d say the bulk of Elle Pots are utilized at the propagation end of things – starting seeds and rooting vegetative cuttings – either for greenhouses to “grow on” themselves or as plug/liner products sold to finishing growers (see student Paul Hutcheson holding a geranium liner above).

Ella and Ojvind Ellegard of Denmark developed the system in the early 1990’s. Popular with growers in Europe, they’ve made their way to North America. Growers can buy in Ellepots by the pallet from various sources, or can invest in the equipment to make them

Wrap it up, I’ll take it…an Ellepot machine at Battlefield Farms, Rapidan, Virginia.

Sizes run from 15 mm (288 cells per 20” x 10” tray) up to 120 mm – equivalent to a 4” pot, perfect for bedding plants. Landscapers love them if they can find them – less waste from installation sites.

Petunia in an Ellepot. That’s Marc Verdel, head grower at Battlefield Farms.

As far as retail goes, I’m not sure if any market research has been done as to consumer preferences for this “pot-less” system. It’s a slight challenge for a shopper to pick one of this and two of that and transport them – you need some kind of carry tray. Anyone out there experienced with Ellepots (grower or gardener)?

Last-Frost-Date Roulette

We all play the game – at least the more impetuous among us do. You sneak a few tender things out into the garden, or on to the patio. When the temperature drops and there’s a frost warning, no problem…just cover them up or bring them in.

Unless you forget.

This WAS a rare and neato Pereskia aculeata ‘Variegata’. Paul W., please send me another…

Before dawn on Monday morning, (May 9) the temperature on our little mountainside dropped below freezing for four hours, going as low as 29.5 F according to our weather station. I had tucked everything back into the greenhouse or up under the eaves…except for the contents of a built-in planter on a far outpost of our deck.

Top o' the frosty mornin' to ya...
Dahlia Mystic Desire, edged in frost at 7:00 a.m., May 10.

NOAA has a handy set of maps that illustrate last dates of “Spring freeze occurrence”. The maps present data averaged between 1951 and 1980.

Walking around the garden last evening with a nice hot cup of martini, I surveyed the damage. Big, juicy-stemmed bleeding hearts that seem so fragile and succulent? Not a speck of injury – but they’ve been up since March. Newly emerged (and really expensive) Asian Jack-in-the-pulpits looked like wet rats. Annuals and tropicals exposed out in the open didn’t stand a chance. Early-to-leaf-out trees can take a beating, too. Japanese maples are notoriously precocious, flinging their fabulous foliage out as much as 45 days prior to last frost here. They’re in pretty good shape now, having acclimated a bit. But for our previous hard frost,15 days ago, we had eight little maples individually draped in white row cover (looked like Halloween).

No longer desirable...
Dahlia Mystic Desire, kaput at 7:00 p.m., May 10.

So why the damage on some and not others? Plants differ in the amount of sugars, proteins, and other compounds that affect the osmotic potential in cells. The lower the content of these compounds, the more likely freeze damage will occur. Young and unacclimated tissue tends to have a higher ratio of water. Like an overfilled water bottle stuck in the freezer, something’s got give as the liquid crystallizes and expands (vast oversimplification, sorry). Cells burst, or are crushed from the freezing of intracellular water, and fluid goes everywhere – hence the limp, dark, water-soaked appearance.

Fog or dew on the plant can delay injury; as external moisture freezes, in gives off heat (an exothermic reaction; one of the amendments to the Laws of Thermodynamics), until all the water is frozen. This is why citrus groves are continually sprayed with water during a freeze event. So it also depends on the duration of the cold; if temperatures just briefly drops below freezing, damage is minimal. Four hours for non-acclimated tissue? See the grim photos for results. Will I wait until May 15 to plant stuff out next year? Absolutely, positively, not. We’re due a no-late-frost spring!

Visiting Professor guest post: Native wildflowers

Recently I have been fascinated by the native wildflower field I planted last fall. Although I seeded it with the same mixture of seeds (mixed with sand to spread them evenly), you can see that we have clumps of different flowers throughout the area.

Figure 1. Descanso Gardens, California

The area where the wildflowers were planted had several 1-2 foot raised mounds; some were in the shape of keyholes. These were built with silty sand from a nearby seasonal stream that had some erosion problems in a rainy year.

Small differences between the temperature, moisture, light and soil on the different parts of each mound have favored different species of wildflowers. In one of the keyholes, I even found some miner’s lettuce (Claytonia perfoliata), a species I had not seeded that favors wetter areas. If I sampled for insects, I bet I might find a similar patchy distribution as well.

As an ecologist/biologist, I am really fascinated by the way that species diversity can be affected by topography, climate, moisture, and soils. As a gardener, I like that I could create conditions that favor different plants just by moving soil around. Plus I think that the waves of color are lovely as well.

Rachel Young is the head of the California Garden at Descanso Gardens, just outside Los Angeles. She has an MS degree in Ecology and Evolutionary biology from UCLA and lectures on various garden and horticulture related topics.

Surviving the desert with beauty and efficiency

I’m away this week for an out-of-state seminar and a little annual leave. Some of my favorite places to visit this time of year are the high deserts of California. Today we hiked to Horse Thief Creek, a relatively easy trail in the Santa Rosa Wilderness. It’s the perfect time of year to see the high desert in bloom, especially with last winter’s substantial rainfall.

In graduate school I became interested in environmental stress physiology, and I still am entranced by the plant kingdom’s ability to overcome nearly every environmental extreme on earth. Desert ecosystems are particularly harsh, as rainfall is limited to a short period of time, often in the winter or spring. While many perennials are able to tolerate the subsequent dry season, annual species cannot. In essence, they escape drought stress altogether by existing only in seed form for most of the year. Seeds contain relatively little water anyway, and are so protected against environmental extremes that they can remain viable for decades or even centuries.

But back to our desert. After the rainy season, seeds of annual plants go into overdrive, germinating, growing, setting seed, and dying back all the span of a few weeks. Thus, the lucky hiker can find an abundance of tiny, brilliant desert annuals when seasons and vacation schedules coincide.

Tomorrow it’s the Salton Sea. Not sure what we’ll see in terms of plant life, but we’re hoping to catch some of the migratory waterfowl on their journey north.

Baffling Daffs

It is daffodil season in the Northern Hemisphere, hurrah! May their blooms shoo away the gray of winter! It is also the season where everybody and their mother writes something about the wonders of the genus Narcissus, so figured I’d join the fray, but with a bit of a chip on my shoulder…

Miss ‘Barrett Browning’ in the Hahn Horticulture Garden at Virginia Tech

I recently read YET ANOTHER article warning against mixing daffodil stems in with other cut flowers due to “harmful effects from the sap”. If stems are conditioned, that is, placed in warm water on their own for 12 to 24 hours, it’s supposed to be o.k. This is repeated in everything from floral arranging manuals to gardening articles, but they never say what exactly causes the problem. So I’ve combed through many resources, to find a specific study backing this up and identifying what compound is responsible.

Known:

1) There is such a thing as “daffodil picker’s rash” which has been reported in the journal of Contact Dermatitis (Julian and Bowers, 1997). The authors attribute this rash to the “crystals of calcium oxalate in the sap, in conjunction with alkaloids, [which] act as an irritant, and also cause the characteristic sores.” Duly noted.

2) Said calcium oxalate crystals are found throughout the daffodil, in the bulb, stem, sap, flowers, etc. Micrographs show that these crystals are needle-sharp, and apparently very painful (I have not gotten up the nerve to give them a nom). This is why deer and bunnies will not eat your daffs.

3) The list of alkaloids is fairly extensive (as with many other members of the Amaryllidaceae family), including masonin, homolycorine, and a real nasty one, narciclasine- which disrupts cell division (meiosis) much like colchicine.

4) Are daffodils poisonous? Yes. If you (or your cat) hunkered down and consumed an entire bulb, problems would ensue. But the calcium oxalate crystals are, perhaps, nature’s way of convincing you (or Mr. Twinkles) that this is not a good idea.

So is there really an effect and if so, what makes daffodil sap deleterious to the other flowers in the vase? The study “Effects of Daffodil Flowers on the Water Relations and Vase Life of Roses and Tulips” by W.G. van Doorn appeared in the Journal of Horticulture Science. Dr.van Doorn found the mucilage (sap) was indeed to blame, with just one daff shortening the vase life of both the tulips and roses by almost half. But what component?

He split out the alkaloid fraction and the sugar fraction of the sap, and then added them as individual components to the vase water. He drew different conclusions as to the cause: the research indicated that the effect in roses is mainly due to the sugar and polysaccharide fraction of the mucilage stimulating bacterial growth. This clogged the rose’s vascular system resulting in bent neck. You’ve seen this before – the bud, yet to open, flops over, never to recover.

These same sugars didn’t impact the tulips negatively but the alkaloids sure did. Even touching the sap to the tulip foliage produced a yellow spot. He was not able to distinguish which of the six alkaloids detected were responsible, but at least narrowed down the cause ( sounds like a job for a grad student!).

So there you have it. I feel better. Am off to pick a few daffodils (very carefully) to brighten my office.

I’m Saving Myself for Pollination

Let’s take a very brief respite from the socio-religious implications of science, soil testing, and compost tea to ponder a more lighthearted topic. I need a bit of a morale-boost.

You: “O.K. Holly, Spring’s allegedly coming…how about a closer look at some wildflowers?”

Me: “Done!” (fingers snapping)

For a short time in March, forest floors across Eastern North America can be absolutely littered with a multitude of sparkling white flowers. This very cool little plant, Sanguinaria canadensis, is one of the first wildflowers to emerge in the spring and colonizes deciduous and mixed woodlands.

Flock of bloodroots, open for business at the fabulous Mt. Cuba Center.

A member of the Poppy family, Sanguinaria is a monotypic genus; that is, there’s only one species. Commonly known as Bloodroot – mostly. However, S. canadensis is also known as (and I quote): Bloodroot, Red Puccoon, King Root, Red Root, Red Indian Paint, Ochoon, Coonroot, Cornroot, Panson, Pauson, Snakebite, Sweet Slumber, Tetterwort. Large Leaved Sandwort, Large Leaved Bloodwort, plus whatever else Aunt Minnie “knowed it by”.

As one of the first wildflowers out of the ground, it’s still darn cold when the Bloodroot flower appears, and they’re quite protective of their private parts. The one leaf emerges at the same time and cups around the flower, helping to protect the fragile blossom from wind, rain, and snow. The petals also close up at night to save the pollen,since in most locations it’s so cold that few insects, save the occasional fly or beetle, are out and about. And as a last resort, they can just “do it themselves”, better described as self-pollination.

I have been pollinated! Victory is mine!

If you break off a stem or piece of the root, out will ooze a reddish-orange juice, hence the common name. It’s been prescribed for myriad conditions by Native Americans and herbal practitioners. One of the more interesting properties is that the sap is an escharotic – it kills tissue. Ironically, according to herbal lore, to draw love to you, wear or carry a piece of the rhizome. If attempting this bit of magic, maybe it’s best not carried in one’s pants pocket.