Garden bloggers bloom day: November 2014

Despite a few evening clouds, it was cold and clear last night in Washington, DC and we finally got our first good freeze of the season.  I've had a couple of very light frosts already, when overnight lows were in the 30's, but without any damage to my plants.  Last night was the first time it went down to the freezing point, 32 degrees F (0 C), or perhaps slightly lower.  When I went out this morning to survey the damage the first thing I noticed was the sickly sweet smell of frostbitten vegetation.  That's the part I always forget.

Spring has sprung

Iris 'Buckwheat'

What a relief that spring is finally here!  In fact the last 3 days have felt more like summer, humid and with highs close to 80.  In addition to the spring perennials cheering me up, I'm seeing recovery on several plants that were badly damaged by the winter and that I thought (or feared) were dead.  To recap, this was the Washington, DC area's coldest winter in 20 years, and was a good test of all the marginally hardy plants we're growing here!  The low in my own yard was about 5 degrees in early January, with several more lows in the 9-12 degree range and several periods of temperatures well below freezing.

Freeze-dried palms and other garden delights

Fronds of Trachycarpus wagnerianus after an extended freeze

Things are not looking good in the garden.  After several days of temperatures well below freezing, I was hoping for a bit of a thaw this weekend but after an initially promising forecast on Friday was revised downward, and my thermometer read only 30 degrees at 4:00 pm yesterday, I think that's as good as it's going to get.  The latest forecast for today is 30 degrees, and 39 degrees tomorrow, but I'll believe it when I see it.  Monday will mark a full week of temperatures below freezing.

It was @!#$% cold last night!

Curled leaflets on a Trachycarpus wagnerianus frond at 5.2 degrees

After several days of practically apocalyptic forecasts, I spent last night listening to the wind and wondering just how cold it would get.  After a rainy and fairly warm morning, at around 5:00 pm the wind had picked up, the temperature started dropping rapidly, and by this morning, local airports had recorded our area's lowest temperatures since 1996.  At 8 am, the official low temperature at DCA (Washington National Airport) was 7° F (-13.9° C) but in my own back yard, the temperature was 5.2° F (-14.9° C), the coldest I've had since buying this property in December 2000.  The next coldest I've recorded was 6° F (-14.4° C) in January 2004.

Single digits next week?

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):


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 japonica at 8 degrees (F) in January 2009

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, December 10, 2011


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, 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.


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.
 

Fabulous Fatsia

Something spooky-looking emerges in my garden in the fall.  Every October without fail, shortly before Halloween, fat buds begin to swell on my Fatsia japonica and from them emerge ghostly flower buds, tightly packed into little balls and looking more like some fungus that would emerge from the grave of a hastily-buried corpse in a science fiction movie.  Only when they fully expand and the thousands of tiny buds open do they begin to resemble actual flowers, and even then it's more like the poor plant had an accident and exploded while it was trying to bloom.