Back from a blogging holiday

We just got back from our annual winter vacation in Fort Lauderdale, Florida.  This was the view right outside our room, and below is our view every morning as we had our coffee.  I'm really going to miss that view tomorrow morning.

More photos coming over the next few days.

Why bother?

Trachycarpus wagnerianus after our coldest winter in 20 years

Just as many growers of hardy palms are wondering whether our palms will survive our coldest winter in 20 years, and whether it's even worth growing them, I came across this in the Plant Delights Nursery February 2014 e-newsletter:

Speaking of weather, winter 2013/2014 has been quite an event in many parts of the country, with temperatures finally returning to more "normal" winter levels. We've amusingly watched the last fifteen years as zone creep, aka: zone denial, has taken hold of much of America. It's been fascinating to observe how quickly peoples' memories of hard winters fade when they are only a couple of years removed. Some gardeners have recently admitted being lulled into a false sense of security by the constant media drumroll that our climate has dramatically warmed forever.

Gardeners in Zone 4 or 5 have a few Zone 7 winters where the winter low temperatures don't drop below 0 degrees F, and all of a sudden they decide that Zone 7 plants will actually survive in Zone 4 and 5. It's not uncommon these days to find less than reputable online nurseries listing plants like the hardy banana, Musa basjoo, as hardy to Zone 4 and 5, which is pure insanity. Windmill palms, which we consider marginally hardy for us here in Zone 7b, have now been planted throughout the mid-Atlantic states and even into parts of the Midwest. Because of the recent mild winters, some windmill palms have actually achieved good size before this winter's reality check. My friend Al Hirsch recently reminded folks on one of the hardy palm groups that he had actually freeze-tested windmill palms in the lab, and 5 degrees F was their low temperature tolerance...except for some of the hardier forms. Just because we've had a string of mild winters doesn't mean the winter temperature tolerance of plants change.

Tony Avent is a global warming skeptic, and I disagree with him on that subject (and one cold winter doesn't disprove global warming!).   But I agree with his main point here: many people have been fooled into thinking certain plants are hardier than they really are, because we've had some unusually warm winters for the last decade or more.  I've seen claims that Musa basjoo is hardy to zone 4, and that windmill palms (Trachycarpus fortunei) are perfectly hardy in zone 7, but pretty much anything is "hardy" with a warm enough winter, or if you provide enough protection.

I don't think anybody is suggesting we should stop growing hardy palms or subtropicals, or anything that might be marginally hardy.  I'm certainly not, and I don't think Tony Avent is either, as he makes a lot of money from selling them to us!  But we shouldn't expect (or pretend) plants to be hardier than they really are.  Winters like this one do happen periodically, they will kill (or severely damage) marginally hardy plants, and for those of us in zone 7, windmill palms are among those marginally hardy plants.  

My own attitude has always been that it's fun to grow plants like this and we should do it if we want to!  But we should go into it with realistic expectations, and should expect to either protect or lose our plants when winters like this one come around.  And we need to communicate those limitations and expectations when we advise or encourage people to grow plants like this.

So are all of our windmill palms in the Washington, DC area dead?  I don't think so.  It's still too early to be sure, but I'm willing to bet that at least a few of the local palms, especially those planted in sheltered locations, will pull through.  Many of us are growing palms from reputedly extra-hardy strains, so it will be interesting to see if that makes any difference.  And regarding Al Hirsh's work, he was testing temperatures that are lethal to leaf tissue under laboratory conditions; whether those same temperatures would kill the same palm growing outdoors is another matter, certainly tied directly to the duration of the low temperatures, which affects how deeply cold penetrates into the trunk, where the meristem (growing point) is deeply buried.  Windmill palms are famous for bouncing back after suffering massive damage from winter freezes, so no matter how bad those palms may look this spring, don't give up hope!  Doesn't a view like this make it all worth it?


Garden, early October

Speaking of weather, winter 2013/2014 has been quite an event in many parts of the country, with temperatures finally returning to more "normal" winter levels. We've amusingly watched the last fifteen years as zone creep, aka: zone denial, has taken hold of much of America. It's been fascinating to observe how quickly peoples' memories of hard winters fade when they are only a couple of years removed. Some gardeners have recently admitted being lulled into a false sense of security by the constant media drumroll that our climate has dramatically warmed forever.
Gardeners in Zone 4 or 5 have a few Zone 7 winters where the winter low temperatures don't drop below 0 degrees F, and all of a sudden they decide that Zone 7 plants will actually survive in Zone 4 and 5. It's not uncommon these days to find less than reputable online nurseries listing plants like the hardy banana, Musa basjoo, as hardy to Zone 4 and 5, which is pure insanity. Windmill palms, which we consider marginally hardy for us here in Zone 7b, have now been planted throughout the mid-Atlantic states and even into parts of the Midwest. Because of the recent mild winters, some windmill palms have actually achieved good size before this winter's reality check. My friend Al Hirsch recently reminded folks on one of the hardy palm groups that he had actually freeze-tested windmill palms in the lab, and 5 degrees F was their low temperature tolerance...except for some of the hardier forms. Just because we've had a string of mild winters doesn't mean the winter temperature tolerance of plants change.
- See more at: http://www.plantdelights.com/index/page/static/subpage/Newsletter_2014February#sthash.Y8cauiMu.dpuf

Speaking of weather, winter 2013/2014 has been quite an event in many parts of the country, with temperatures finally returning to more "normal" winter levels. We've amusingly watched the last fifteen years as zone creep, aka: zone denial, has taken hold of much of America. It's been fascinating to observe how quickly peoples' memories of hard winters fade when they are only a couple of years removed. Some gardeners have recently admitted being lulled into a false sense of security by the constant media drumroll that our climate has dramatically warmed forever.
Gardeners in Zone 4 or 5 have a few Zone 7 winters where the winter low temperatures don't drop below 0 degrees F, and all of a sudden they decide that Zone 7 plants will actually survive in Zone 4 and 5. It's not uncommon these days to find less than reputable online nurseries listing plants like the hardy banana, Musa basjoo, as hardy to Zone 4 and 5, which is pure insanity. Windmill palms, which we consider marginally hardy for us here in Zone 7b, have now been planted throughout the mid-Atlantic states and even into parts of the Midwest. Because of the recent mild winters, some windmill palms have actually achieved good size before this winter's reality check. My friend Al Hirsch recently reminded folks on one of the hardy palm groups that he had actually freeze-tested windmill palms in the lab, and 5 degrees F was their low temperature tolerance...except for some of the hardier forms. Just because we've had a string of mild winters doesn't mean the winter temperature tolerance of plants change.
- See more at: http://www.plantdelights.com/index/page/static/subpage/Newsletter_2014February#sthash.Y8cauiMu.dpuf

Speaking of weather, winter 2013/2014 has been quite an event in many parts of the country, with temperatures finally returning to more "normal" winter levels. We've amusingly watched the last fifteen years as zone creep, aka: zone denial, has taken hold of much of America. It's been fascinating to observe how quickly peoples' memories of hard winters fade when they are only a couple of years removed. Some gardeners have recently admitted being lulled into a false sense of security by the constant media drumroll that our climate has dramatically warmed forever.
Gardeners in Zone 4 or 5 have a few Zone 7 winters where the winter low temperatures don't drop below 0 degrees F, and all of a sudden they decide that Zone 7 plants will actually survive in Zone 4 and 5. It's not uncommon these days to find less than reputable online nurseries listing plants like the hardy banana, Musa basjoo, as hardy to Zone 4 and 5, which is pure insanity. Windmill palms, which we consider marginally hardy for us here in Zone 7b, have now been planted throughout the mid-Atlantic states and even into parts of the Midwest. Because of the recent mild winters, some windmill palms have actually achieved good size before this winter's reality check. My friend Al Hirsch recently reminded folks on one of the hardy palm groups that he had actually freeze-tested windmill palms in the lab, and 5 degrees F was their low temperature tolerance...except for some of the hardier forms. Just because we've had a string of mild winters doesn't mean the winter temperature tolerance of plants change.
- See more at: http://www.plantdelights.com/index/page/static/subpage/Newsletter_2014February#sthash.Y8cauiMu.dpuf

Waggie vs. Nainital

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

Not all windmill palms are created equal.  In fact there seems to be quite a bit of variation in cold hardiness among them, with some selections or strains reputed to be hardier than others.  The above photo illustrates very clearly such a difference.  Many sources claim that "waggies"--Trachycarpus wagnerianus, which is probably no more than a dwarf version of T. fortunei that arose in cultivation--are among the hardier windmill palms.  In fact, that's why I ordered seeds of this species 13 years ago, when I was just starting to get into hardy palms.  But after this winter, I'm not so sure about that.

The windmills of Washington

For the last two decades, some of the more adventurous gardeners in the Washington, DC area have been planting Trachycarpus fortunei, commonly known as "windmill palm".  Although the dwarf palmetto (Sabal minor) and needle palm (Rhapidophyllum hystrix) are considerably hardier, the windmill palm is the hardiest of the palms that grow trunks and can properly be called "palm trees".  Exactly how hardy is still a matter of debate, and our coldest winter in 20 years will surely put these palms to the test.  A general rule of thumb is that single digit temperatures are likely to cause damage, and temperatures below zero will cause massive damage and in many cases kill the palm outright (although duration of the cold is also critical).  This makes windmill palms marginal in zone 7: sooner or later, they will experience temperatures capable of killing them.

Snowmageddon four years later

It has been exactly four years since the snowstorm that the local media dubbed Snowmageddon.  Many parts of the Washington, DC area got over 24 inches of snow, and that was on top of several inches of snow we had gotten just days earlier.  First, some photos from the earlier snowfall, which gave us just enough snow to make the city beautiful!  The above photo shows our neighborhood from our upstairs windows.

Credit where credit is due

Primulina (Chirita) 'Chastity', Green Spring Gardens conservatory

As an amateur plant breeder, I appreciated these comments by Kelly Norris as quoted by Allan Armitage in a recent article about the future of plant breeding in Greenhouse Grower magazine, Today's Breeders on Tomorrow's Plants:

"There are those coming of out graduate school who end up toiling away with petunias and commodity crops. I feel for them," he says.  "Then there are those of us in 'private practice' (a.k.a. unpaid hobby breeding) or working for public institutions that don't have to live by the rules.  We take risks, run into road blocks (like lack of funding or time) and fail more than we succeed.  But we are passionate and believe in what we encounter in the public — an earnest desire to be fascinated by plants and to want something different than what they so often encounter.  It's this class of breeders that stand the chance of advancing the cause of plant breeding because they are champions of new genera."