Yep – autumn color – things aren't so green anymore. Last night (Oct. 1) we dipped down to 29 F...another temperature record for the date. I don't know, but with our greenhouse doors closed I guess we escaped any lasting damage. The water pipes didn't burst, thankfully, but we were only about two degrees short of that disaster. The majority – actually all – of my employees went to bed last night without any concern, as did my family, leaving old Buchholz alone to fret without support.
Acer palmatum 'Sango kaku'
|Acer palmatum 'Little Sango'|
Looking out my office window the behemoth Acer palmatum 'Sango kaku' has turned as orange as a pumpkin and is particularly striking in combination with the clear blue sky. Originally I bought a pair of the “Coral Towers” and planted them on either side of the path. Early on one died so my symmetry was ruined, but the survivor is now 46 years old and is the largest I have ever seen. I'm positive that it's not the largest in the world, just the largest that I have ever seen.* I haven't produced 'Sango kaku' for over twenty years, the reason being is that everyone else does. The cultivar can look dreadful when a two-inch caliper tree gets only a 12” square of soil at the front of a nearby box store. Out of about twenty trees I guess five look happy, but the others are hampered with black stems and split trunks. Anyway, instead of 'Sango kaku' I like to produce the more dwarf version, 'Little Sango', where you look sideways at the red stems in winter.
*After all, 'Sango kaku' was introduced in 1882.
Acer japonicum 'Aconitifolium'
A specimen of Acer japonicum 'Aconitifolium' is the same age, but the poor thing is so full of lichen that I'm frequently tempted to cut it down. It actually beings the transformation of green leaves to red about the first of August, and at this time there is little left. Except for the lichen the tree is healthy and receives adequate moisture, so I don't know why it turns so quickly. 'Aconitifolium' used to be called 'Laciniatum' and 'Filicifolium', so all three names are unimpressive and I prefer the Japanese name of 'Maiku jaku' which translates as dancing “peacock.” In any case it was introduced way back in 1888, only 24 years after the japonicum species itself was introduced to Europe (1864).
|Acer saccharum 'Sweet Shadow'|
Acer saccharum 'Sweet Shadow'
|Acer saccharum 'Monumentale'|
Acer saccharum 'Sweet Shadow' is on fire, and the flames begin with a light yellow coloration with just a cast of orange. Today the foliage has evolved to a deeper orange, and in about two weeks it will peak with a fiery red-orange, and my one old specimen has never failed to impress me. The Maple Society of North America will be visiting on October 25, which is perfect timing for dazzling color. Oddly Acer saccharum 'Monumentale' is still completely green today, but it's planted in an area that receives more irrigation, and I think that's what delays the autumn color. A “Sugar maple” used to be next to the office – I never knew the name since I didn't plant it – but I also located my first container area next to it which was watered frequently throughout summer and fall. The Sugar displayed fantastic color only after I moved the containers away. Sadly that tree is gone; it was weakened by incessant drilling by a sapsucker or woodpecker so we finally cut it down. Its short stump remained and it grew an orange fungus which would develop every fall. After five or six years the Sugar's fungus food finally petered out, but it was a fun spectacle while it lasted.
The Pacific Northwest is famous for its “Vine maple” species, Acer circinatum. I mentioned in the paragraph above that Acer saccharum's fall color can be influenced by the amount of irrigation it gets or doesn't get. I remember that the famous maple author, Peter Gregory, said that the Sugar maple does not produce outstanding color in England. But I wonder where in England – was he talking about one or several specimens at Westonbirt Arboretum where he was director years ago? Certainly there must be places in England with lean soil that receive less rain than at Westonbirt, so how would they do there? While not in England, I can picture a Sugar specimen in the Scottish Highlands, and I bet it would look brilliant in autumn. The two photos above were taken on the same day on Mount Hamilton in Washington state along the Columbia River Gorge. The October photo at left is Acer circinatum growing along the stream at the bottom of the mountain, and two miles later the Vine maple's color was red near the top where the soil was more sparse and rocky. Both the low and high elevations receive the same amount of rainfall, but with different amounts of water retention.
The photo of the Vine maple above was taken in a plant friend's collection at the end of May, and the little tree was already displaying autumn color. It was a delightful sight, and at first I thought she had acquired a red cultivar new to me. But the skinny is that the maple was planted on a flat rock with some small groundcover at the edge to keep the soil contained, and I suppose her little “dish” required daily attention in summer so it wouldn't dry out and scorch. I was so fascinated with her creation – and I have lots of flat rocks at the nursery – that I wanted to rush home and plant a hundred of them, but the reality of another project for me to micromanage kept me from doing so.
Acer palmatum 'Hogyoku'
Earlier in my career I had a row of Acer palmtaum 'Hogyoku' displaying lustrous green leaves in July. Sometime in August leaves on one small branchlet turned brilliant orange, and though I walked past it every day I didn't give much thought to the event. Finally I stopped to inspect and I noticed the branch had broken, probably caused by me when I was cutting scions, but it was still hanging on by a little bit. The following year I intentionally half-broke a branchlet on 'Osakazuki', but apparently not enough as it remained green. The next year I tried it again but the leaves turned brown, so apparently I broke it too much. That was 30 years ago and I haven't done it since, but I encourage all blog readers to break a branch and see if you can duplicate what I accomplished by accident.
|Sempervivum 'Gold Nugget' in October|
|Sempervivum 'Gold Nugget' in January|
Of course it's not only deciduous trees that change color in autumn. We have been growing Sempervivum 'Gold Nugget' for a few years. The foliage is not much of interest in summer with kind of a lime-green color, but now it has changed to a more yellow. The best will come later in winter when red tips develop on the fleshy leaves.
|Pinus mugo 'Ophir' in October|
|Pinus mugo 'Ophir' in December|
Color on some conifers is changing as well. In summer Pinus mugo 'Ophir' is a non-event – just another boring pine – but today when I walked past I noticed it beginning to evolve to its yellow winter color. There are pines that produce a more dramatic winter color than 'Ophir', such as with Pinus contorta 'Chief Joseph', but it's the glowing nature of 'Ophir's' yellow that is more accomodating with surrounding garden plants.
A lot of plants change color in autumn, and I guess that I have also if you consider me (with my gray hair) to be in the “autumn” of my years. At least I hope I'm in autumn, not in the dead of winter.