Tuesday, December 31, 2013

Single digits next week?

Frozen palm leaf
Trachycarpus wagnerianus at 8 degrees (F) in January 2009

Cold weather is sweeping south from Canada later this week, with temperatures in Washington, DC possibly dropping into the low teens (F) by Saturday, and maybe even into the single digits next week.  Personally, I don't trust any weather forecast that's more than 3 or 4 days away.  But let's face it, this is winter, and winter gets cold!  We've been very lucky the past few years, with warmer-than-average winters, and sooner or later winter has to catch up to us.

These would be the coldest temperatures my plants have experienced since January 2009, when I recorded 8 degrees (F) in my back yard.  After that cold spell, several of my hardy palms suffered serious damage.  The first sign of trouble was the freeze-dried appearance of the fronds of Trachycarpus wagnerianus (as seen in the photo above).  These fronds ended up dying and the plants were nearly defoliated.  None of them died outright, putting out new growth the following summer, and fortunately we had a series of warmer winters after that, with nothing lower then the mid-teens.  Even so, two of my "waggies" were so weakened that they succumbed to the following winter, even though it was considerably warmer.  The one survivor has put out very strong growth since then, possibly because they were planted too close together and its competition was eliminated!  Here is how it looked in October 2012, next to Trachycarpus fortunei "Nainital" (which has proven much hardier for me and sailed through the 2008-2009 winter with minimal damage):

Hardy palms
Trachycarpus wagnerianus (left), T. fortunei "Nainital" (right)

I always have mixed feelings about these winter forecasts.  On the one hand, I don't want to lose any plants, especially not palms that I've grown from seed or otherwise invested with a decade of cultivation.  On the other hand, I want to find out how hardy they really are, and protecting them won't tell me that. I made a conscious decision several years ago that I was willing to risk losing the plants and I haven't protected any palms since February 2005, and then only my Trachycarpus wagnerianus as they were still very small seedlings.  None of my other palms have ever received any protection other than a generous layer of mulch.  Frankly, I find it too much work to protect plants and you can see how much effort I put into it for my "waggies":

Sophisticated palm protection, February 2005

Incidentally, this is what my fatsias looked like after the same cold event--believe it or not, they completely recovered from their infamous "fatsia flop" with no damage whatsoever:

Fatsia flop
Fatsia japonica at 8 degrees (F) in January 2009

Sunday, December 29, 2013

All planted!

Seeds planted

Phew!  I've just finished planting the last of the begonia crosses I made this year.  This is the third batch of seeds I've planted, for a total of about 25 unique crosses using around a dozen different parents.  The seedlings from the first and second batches are already good-sized so I'll need to do some repotting soon!   This photo gives some idea of just how small the seeds are--generally about 0.5 mm in diameter:

Begonia seeds
Begonia seeds, ready for sowing

My experience with growing and breeding gesneriads gave me a good head-start with begonias.  With both groups, the tiny seeds must be sown directly on the soil surface.  I've always heard they require light to germinate, but I've never tested this as they just go on my light stand anyway, in clear or translucent plastic boxes that help keep them warm without drying out.

For sowing begonia (and gesneriad) seeds, I've generally had good results using Pro-mix.  This year the garden center where I usually buy it was all out, so I tried Espoma Organic Potting Mix instead and have had similarly good results.  The sowing medium should be fairly fine (I pick out the largest grains of perlite), well-drained, and not have fertilizer added.  I find that mixes that contain fertilizer tend to burn the seedlings. I generally see the first seedlings within a week, and within two or three weeks the pots will all look like this--assuming the crosses were successful!

Begonia seedlings
Begonia seedlings

Friday, December 27, 2013

Edgeworthia chrysantha

Edgeworthia chrysantha
Flower buds of Edgeworthia chrysantha in December, promising fragrance in spring

Edgeworthia chrysantha, sometimes known as "paperbush", is a Chinese species in the same plant family (Thymelaeaceae) as the far better-known Daphne.  I wanted to grow this species because I like fragrant flowers, and it was supposed to bloom in the winter.  I also liked the large, almost tropical-looking foliage.  When I spotted the species a few year ago at a Friends of the National Arboretum (FONA) spring plant sale I purchased one and planted it in my garden.

Foliage of Edgeworthia chrysantha.  Norfolk Botanical Garden, Norfolk, Virginia

Edgeworthia chrysantha
Edgeworthia chrysantha in my own garden

The plant has an odd branching habit, which is most noticeable after the leaves are killed by frost (they have no fall color, unfortunately).  The nodding clusters of buds are covered with silvery hairs and provide some winter interest, but not much.  One oddity of this species is that it blooms on bare stems in late winter or early spring before leafing out.  In my own garden, it blooms for several weeks beginning in late February or early March.  The intensely fragrant flowers open deep yellow, turning white as they age.  The flowers do not produce petals; what appear to be petals are actually fused sepals.  Some selections have orange flowers.

Edgeworthia chrysantha
Edgeworthia chrysantha flowering in March

Edgeworthia chrysantha
Flowers of Edgeworthia chrysantha, showing the 4-lobed calyx

Edgeworthia is a small genus of only 5 species, 4 of them occurring in China.  The genus name honors Irish botanist Michael Edgeworth and "chrysantha" means "golden flowered".  The species was described by John Lindley in 1846, based on a collection by Robert Fortune in Chusan (Zhoushan), China.  The plant eventually grows into a large, spreading shrub.  It is undemanding and easy to grow, doing well in part sun or bright dappled shade.  The large leaves contrast well with smaller, finer foliage.  Alternatively, it can be used as a softening counterpoint to masonry or stone.

Haupt Garden
Edgeworthia chrysantha in the Enid A. Haupt Garden, Smithsonian Institution, Washington, DC

Tricyrtis and Edgeworthia
Edgeworthia chrysantha (upper right) with Tricyrtis and Buxus. Private garden, Kensington, Maryland

As it turns out, this is a moderately variable species with respect to both growth habit and leaf size.  The plant I picked out is one of the smaller-leafed selections, not producing the large leaves I liked so much.  As for placement, I may have miscalculated a bit as this species can grow rather large.  But the fragrant flowers it produces when nothing else is blooming make up for any drawbacks!

Further reading:

Just one plant: Edgeworthia chrysantha
A shrub for all seasons: Edgeworthia
Edgeworthia chrysantha (oriental paperbush)

Sunday, December 15, 2013

Schefflera delavayi

Schefflera delavayi
Schefflera delavayi, well-mulched for the winter

When I visited Plant Delights Nursery in Raleigh, North Carolina this past July, among several impulse purchases was a seedling of Schefflera delavayi (Araliaceae), a Fatsia relative from China with large, glossy, tropical-looking evergreen leaves.  I just couldn't help myself, especially after seeing a larger specimen growing on the property

Schefflera delavayi
Schefflera delavayi at Plant Delights Nursery

I didn't get it planted until September, largely because I couldn't figure out where to put it (a common problem with impulse purchases!). This is on the late side for a marginally hardy plant; I generally try to get such plants in the ground in the spring to give them a full growing season to get established before winter comes.  I've mulched it heavily with leaves, and if truly cold weather is in the forecast I may use the sophisticated protection method I developed to protect some of my hardy palm seedlings during their first two winters.  I prefer to grow plants unprotected, but I'll make an exception for something new and unusual that isn't yet established, just to give it a fighting chance.

The Plant Delights catalog warns that this is a slow-growing species, especially in the heat of the southeastern USA.  Growth is apparently faster in the cooler climate of the Pacific Northwest, where more people seem to be growing it.  The catalog describes the species as hardy to "zone 7b to 9b, at least" and having survived 8 degrees without protection.  The last time my garden experienced a low of 8 degrees was February 2007, so if DC winters keep up their recent warmer-than-average streak, I think my chances with it are pretty good.

The species has a wide range in southern China where it grows into a small tree, producing tiny white flowers in the fall.   Schefflera delavayi (Franch.) Harms was originally described in 1896 by French botanist Adrien René Franchet as Heptapleurum delavayi, the name honoring Père Jean Marie Delavay, who collected this species in Yunnan, China in 1889.  It was transferred to the genus Schefflera in 1900 by German botanist Hermann Harms and (except for a brief excursion into Agalma in 1967 that few botanists seem to have noticed) there is has remained.  Ah, but for how much longer?  Recent studies on this pantropical genus have revealed that it's an unnatural group and the Flora of China treatment of this genus suggests Schefflera delavayi (and all other Chinese members of this genus) will end up in some other genus.

This seems to be one of those plants that's so new that everybody is growing it.  Several other bloggers have already provided some good information and photos but most of the information seems to be coming from the Pacific Northwest.  Is anybody else trying this species in zone 7 on the east coast?

Thursday, December 12, 2013

The begonia that broke my heart

Begonia hybrid
Unnamed begonia hybrid, a heartbreaking beauty (June 2012)

I hope to (eventually) blog about some of my successes with begonia breeding, but for now I'm going to describe one of my failures.  The plant in the above photo is one of my own hybrids, photographed in my garden in June 2012, from a cross I made in 2011.  I call it a "beautiful failure" because it ultimately failed several critical tests, and as of 2013 I'm no longer growing it at all.

Tuesday, December 10, 2013

2013 begonia breeding comes to an end

Begonia 'Taconite'
Male flowers of Begonia 'Taconite', strutting their stuff

It's officially the end of the 2013 begonia breeding season for me.  I made at least 20 different crosses this year, but all my begonias have finally finished blooming and the last capsule of the last cross has ripened.  I already have some good-sized seedlings from the first few crosses, and small seedlings from some later crosses, but I'll need to do one more round of sowing of the very last crosses.  I'm running a little lat this year; I try to get all my crosses planted by early December so the resulting hybrid seedlings will be big enough to plant out in the garden by spring, usually early May.

Monday, December 9, 2013

Yikes! Ice!

Iced palm
Windmill palm (Trachycarpus fortunei) after freezing rain

As a quick update to yesterday's post, the light morning snow changed to sleet later in the day, and to freezing rain sometime during the night.  And when it comes to palms, ice is the enemy!  Fortunately everything had just a light coating of ice, just enough to bend all the fronds down but no so much as to break them.  But now we have more snow moving in.  After several unusually mild and snow-free winters, maybe this will be the winter to put my hardy palms to a proper test?

Sunday, December 8, 2013

Blogging on the learning curve

Isabella, waiting for her own chance to blog

In case you couldn't tell (and my blog being just two months old should have been a hint), I'm not terribly experienced with this newfangled blogging thing.  I tried blogging several years ago with a blog I called Darwinblog but I didn't have a particular focus and never really found my voice.  I blogged about evolution, about weird plants, and about gardening, but guest blogging by my cat turned out to be the most popular posts.  I eventually lost interest and the blog petered out but when I was out of work a few months ago (thanks to the shutdown of the federal government), I decided to occupy my time by blogging again.  I've finally decided that garden blogging is my niche but I won't rule out a cat post or two!

Please bear with me while I play around with the blog's format and layout.  I've switched to black print on a white background, and added a new background image.  One criticism I've already received with the current setup is that the background image is too busy and distracting.  What can I say?  I love the image.  It was the result of playing around with an old image with IrfanView.  I got it by applying the "edge detection" effect to this photo:

Elephant ears

In another version, I first applied the "explosion" effect, followed by "edge detection":

Playing around 2

So how about it: what do you think of the new format and layout?  What am I doing right?  What could I be doing better?  What should I be blogging about?  I'm open to any and all suggestions so please post your constructively critical comments below!  And if you're on Facebook, please "like" my DC Tropics page to be notified of new blog posts!

First snow!

Palm in snow
Trachycarpus fortunei in snow

I woke up to a light snow this morning, the first of the season.  Just that little bit of white completely transforms the garden, making the palms in particular pop out.  Windmill palms (Trachycarpus fortunei) are hardy to at least the single digits and as long as the snow stays light, it won't cause any harm at all.  Even wet, heavy snow will usually only bend the fronds down, but they can break under its weight so it's generally best to brush it off.  Today's forecast is for 1-3 inches of snow, which doesn't worry me.  The problem is that the snow is forecast to turn to sleet and/or freezing rain later in the day, and that can definitely cause damage.  Again, knocking the ice off with a broom is the best defense.  I suppose I could cover my palms, or tie up the fronds as some people do, but frankly, that's just too much work.  I consider myself a zone-pusher and a minimalist gardener, both of which mean I'm just too damn lazy to do things like protect my plants.  I'll give them a good mulching in the fall but otherwise they're on their own until spring.

Here's an overview of the entire garden, as seen from our rooftop deck:

First snow

And a closeup of the upper section of the garden after a bit more snow had fallen:

First snow

Friday, December 6, 2013

×Gloximannia 'She's Dancing'

 x Gloximannia 'She's Dancing'

What the heck is a ×Gloximannia?  (The "×" or multiplication sign, indicating an intergeneric hybrid, is not pronounced.)  In a previous blog post I discussed the gesneriad genus Seemannia, a close relative of Gloxinia.  Although these two genera look very different, they are closely enough related that their respective species can be easily crossed to produce viable hybrids.  And what do you get if you cross the two genera?  The nothogenus (hybrid genus) ×Gloximannia, of course.  To the best of my knowledge, only Gloxinia perennis has been used from that genus and the hybrids tend to take after this parent.  Neither of the other two species--Gloxinia erinoides and Gloxinia xanthophylla--have yet been crossed with any Seemannia species; it would be very interesting to see how such hybrids would turn out.

Sunday, December 1, 2013

End of the Season


The end of the growing season has arrived for my hardy banana (Musa basjoo) and the rest of my garden as well.  I took the above photo on my return to Washington, DC two weeks ago after being unexpectedly out of town for 9 days and found that there had been a hard freeze while I was gone.  This wasn't entirely unexpected; I usually get my first light frost in mid November and a hard freeze in mid to late November.  This is something that those of us growing tropical and subtropical plants in zone 7 have to confront sooner or later: they don't take well to freezing temperatures!  On the other hand, the first hard freeze sometimes comes late enough that many of my plants look good well into December.  But not this year!  Because the following days were forecast to bring colder-than-usual temperatures, with nights in the mid-20's, I spent the day before leaving to visit my family in Buffalo for Thanksgiving scrambling to mulch plants and bring in any potted plants I wanted to save.

For most plants, putting the garden to bed simply means mulch, but I also have a lot of begonias in pots that need to be brought in.  These two photos show the dramatic effect of an overnight freeze on a potted plant of Begonia sizemoreae two years ago, when our first hard freeze didn't come until early December:

Begonia sizemoreae
Begonia sizemoreae, December 10, 2011

Begonia sizemoreae
Begonia sizemoreae, December 12, 2011

The second photo was taken the next morning while the plant was still frozen, and the discolored leaves turned to mush shortly afterwards.  Note that several of the leaves didn't freeze, and are still healthy and green.  When temperatures are near freezing a single degree makes all the difference, and even a little shelter--sometimes even the plant's own upper leaves--can prevent a plant from freezing.  But many of my other begonias are planted directly in the ground to test for hardiness, and sometime before the first frost I take cuttings of any I want to save so I can propagate them indoors over the winter as insurance:

Begonia leaves
Begonia leaves, ready for propagation

For my hardy palms, the only protection they receive is a thick mulch of autumn leaves around the base.  For my begonias and other marginally hardy herbaceous plants, I generally apply a mulch of 1-2 inches of Leafgro (a locally produced leaf compost) followed by another two or more inches of fallen leaves, which I gather in my own yard, from my neighbors' yards, and even in the alley behind the house.  When I peek under this mulch during the winter, I often find that the mulch itself is frozen solid but the soil just below it is not.  For many marginal plants, that little bit of mulch can make the difference between surviving and not surviving.

Finally, for my banana I use what I call my "big pile o' crap" method of protection.  Autumn leaves, the banana's own leaves, and anything else I cut down in the garden are thrown in a big pile around the base of the pseudostems.  In the past it has even included a Christmas tree.  It isn't pretty, but it does the job.  By spring much of it has already decomposed, and I leave it in place to help nourish the plant.

Forlorn Musa basjoo
Pile o' crap  method of protection

So after a hard freeze and a bit of cleanup, this is what I'm left to look at.  Fortunately the palms, the fatsia, and a clumping bamboo (Fargesia robusta) provide some green color all winter.
Early December

Home from the Holidays

I just returned from spending Thanksgiving with my family in Buffalo.  My mom and dad still live there and I recently wrote about growing up there.  Here is a photo of the house where I grew up, in a suburb several miles south of Buffalo.  Yes, I had to shovel the driveway before Thanksgiving!  Unfortunately my father recently had a massive stroke; he's recovering (and far better than anybody expected) but I'm not sure they will be able to keep this house much longer.


There are so many memories tied up in this house; my father was always a gardener and I learned so much from him while I was growing up here.  Here is a view out of my old bedroom window on the back of the house; hard to tell from this photo but the rhododendrons are about 10 feet tall and are smothered with gorgeous flowers in the spring.  My father is justifiably proud of them.  It's going to be hard for all of us to give up this house, where my parents have lived since 1968.

Back yard

Western New York is sparsely populated and has some beautiful farmland and countryside.  Spending time there while my father was in the hospital made me uncharacteristically homesick.  I even miss the snow... for a few days!  Otherwise winters are one of the things I don't miss.  I spent a few days staying with my sister and this is the view out of her back door, overlooking farmland in a valley of the Boston Hills:

Back view