My nursery more-or-less survived Oregon's record-smashing heat wave two weeks ago when temperatures soared to 116 F (46.7 C), accompanied with a brisk PM wind besides. At first it didn't seem that we had suffered exceptional plant loss – some maple leaves fried of course, and hemlock needles went from green to brown – but now the evidence that a number of plants were severely damaged, up to...and including death, has eventually become apparent.
I guffawed when the weather news (of last week) reported a “heat-wave” record in Las Vegas, Nevada, a toasty 117 F. But wow, their all-time heat record, in a hell-hole used to regular 100 F+ temperatures, seems rather wimpy in comparison. Just one flipping degree higher! At the same time Death Valley, California notched its third highest bakery ever at 130 F, but just 14 degrees more than Portland's miserable experience. And of course no one attempts to grow Japanese maples or hemlocks there.
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| Abies koreana 'Ice Breaker' |
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| Pinus koraiensis 'KG' |
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| Tsuga diversifolia 'Greenball' |
My plants fall into one of three categories: 1) dead or severely damaged, and will be dumped the sooner the better. A few examples include my oldest Abies koreana 'Ice Breaker', Tsuga diversifolia 'Greenball' and Pinus koraiensis 'KG' (AKA 'Gee Broom'). The first and last are of witch's broom origin, so mutants then, which are often problematic anyway. 'Greenball', a dwarf round cultivar of the “Northern Japanese hemlock” was located in two different areas on the nursery grounds and both look dreadful. Fortunately it has not been in production for over ten years, so we'll dump them and plant something more durable.
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| Tsuga mertensiana |
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| Picea omorika 'Osmaston' |
The second category is damaged plants, but still keepers. Tsuga mertensiana cultivars, selected for delicious blue foliage, now groan with a cast of brown, ugliness that I'll have to put up with until they flush again next spring. Picea omorika 'Osmaston' fried, whereas other “Serbian spruce” dwarves did not, but 'Osmaston' is a low-growing selection with thin twiglets and tiny needles so I'm not overly surprised.
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| Acer palmatum 'Fairy Hair' |
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| Acer palmatum 'Bloody Talons' original seedling |
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| Acer palmatum 'Bloody Talons' grafted on Acer palmatum |
The third category, and fortunately that's 90% in the nursery, ask “Heat wave? What heat wave?” To be sure, they appreciated the extra water they were given, and some look a little tired like we're at the end of August, but overall they are fine and I'm still in business. Other than a reddish hue to the leaves, the toughness of the delicate-looking Acer palmatum 'Fairy Hair' is remarkable. My original seedling of Acer palmatum 'Bloody Talons', now about 12 years old, displays damaged leaves, but 100% of those grafted on vigorous palmatum rootstock do not.
I won't dwell on my ordeal as you all have your own problems. Thanks to my hard-working, diligent crew, we managed to stay safe and keep the place going. The heat event was dubbed by one climatologist as “one in a thousand years.” Let's hope he's right.
