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.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.
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.
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
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
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
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
I will mourn my winter loses and move on. Replanting some, not others. It's what gardening is all about! However I hold those plant sellers who are overly optimistic with their zonal ratings responsible for discouraging a a whole group of gardeners who may not know any better. Proper labeling is a must!
ReplyDeleteHave the fun of gardening is in experimenting. If everything survived, we would never have any room to try anything new! The problem with zone ratings is that people expect them to be perfectly predictive, and they never will be. The USDA "hardiness zones" are simply numbers calculated from low temperatures, and say nothing about other factors like duration or frequency of those temperatures, or summer temperatures--all of which can vary quite a bit from one "zone 7" to another. The zone ratings are a crude tool we use in lieu of any better system anybody has come up with yet, and must ALWAYS be taken with a grain of salt.
DeleteI am optimistic, too. I will replant all but the most ridiculous experiments I did for kicks. Of course, who knows yet, at this early date, what will and will not survive. If some of my things come back from the root, I'll be thrilled. I am patient.
ReplyDeleteI'm reserving judgment on any of my plants until May or June! But I like to point out that the way successful gardeners became successful was by killing a lot of plants and I've sure done my share. We will never learn anything by staying entirely within our comfort zone, never experimenting, and never pushing the envelope.
DeleteI am fairly new to following your blog, and am very sad that many of your sub-tropical plants may not pull through this winter, or will at best be set way back. I don't have a yard, but I bet if I did i'd be playing the same game. I was in VA beach last weekend and the zone creep there is amazing with more palm trees at the ocean front than Charleston (mostly Sabal palmetto, some Butia and Trachycarpus. The ones that were actually inland a couple of blocks/sheltered from the ocean wind/more than 2-3 years established didn't actually look that bad, and the Trachy's actually looked worse than the Sabals. Lots of all yellow leafed Sago's too and some noticeable burn/defoliation in the live oaks, though they're a proven native of VA beach and have dealt with cold like this before. Actually the day I was at First Landing SP it started to snow lightly, which was very fun to see with spanish moss next to me!
ReplyDeleteI do think that duration has a lot to do with it; Virginia Beach and other parts of southeastern Virginia had some unusually cold (for them) temperatures this winter, but the duration was short enough that I think that many of even the most damaged-looking plants will recover.
DeleteSpanish moss is fairly well-documented to have grown in southern Maryland in colonial times--quite a bit north of its current northernmost range--but despite persistent rumors that it can still be found there, nobody has managed to document it with either specimens or photos.
I hope for the sake of the hotels and the locals alike that the plants can recover from this winter down in VA beach. It was 77 degrees down there last week and it got back into the teens again last night!
DeleteOh Spanish Moss in MD. I've also seen the documentation of this but i'm still not a believer of it having existed. I grew up in Calvert County, only a mile or so from the Bald Creek cypress swamp. I was that kid who would visit family further south, bag up Spanish Moss and throw it in our trees (mostly sweet gum that I could reach). The stuff looked great all summer and that first (it was a mild winter) winter did ok, but between the birds and the second winter, it was all but dead soon enough. Granted we were a mile inland from the tidal waters, and to have any real hope of the moss surviving I should have been in a sheltered back bay overhanging the water, but I still don't know if I believe it's ever actually lived in MD before. Maybe an experiment should be done with someone hanging some moss out of the cypress along the Pocomoke River - if it'll work anywhere it'll be the banks of the Pocomoke in Worcester County.
One point I forgot to make in my blog post is that I disagree with Tony that gardeners have been "lulled into a false sense of security" by the media reporting on global warming. In many regions they have been lulled by a series of winters with above-average low temperatures, and that's an objective fact completely independent of the idea of global warming. This winter may have been a shock to many gardeners, but we've been overdue for a properly cold winter for quite some time.
ReplyDelete