So there I was earlier this week, on the way to see a client in Wellesley, MA, and I passed this huge colorful streetside show:

Trees with colorful flowers? Think about it: How many of them bloom early in the Spring? All those pink cherries. Those pink or yellow magnolias. Rosy-pink "redbuds"? Those lavender paulownias?


And then, the dogwoods come out, and so all the trees thereafter have white flowers only? Stewartia, catalpa, fringe tree, franklinia. Think about it: A tree that blooms later than May and doesn't have white flowers?


Only two, I think: Mimosa (pink blossoms, ugh) and the other one here on that Wellesley streetscape: Goldenrain tree.  Ugh, what a sticky-sweet name, and way too similar to yet another early-Spring yellow-flowered tree (Golden-chain tree, laburnum) plus a climbing rose (Golden Showers).


Let's flip over into the Latin:Kohlreuteria paniculata. Thank you, Mr. Kohlreuter whoever you were. "Paniculata" means that it has big panicles of flowers. Does it ever:

I had never gotten this close to the flowers before—get a load of my grimy man-of-the-earth fingernail!—so I was surprised to see the orange-red flare at the base of the petals.  The pollen is orange-red too—nice coordination!—and the petals are folded back to expose it completely.


Kohlreuterias in my experience are fool-proof as long as they're planted up a slope, even a tiny one.  They lose their confidence if surface water doesn't drain right away.
Sun and heat are welcome, and the trees are drought-proof too.   So tough they can be used as street trees.


We'll take another look at kohreuterias later in the season: As if these unique flowers weren't enough, they mature to colorful inflated pods by August.


In the Fall we'll confirm if the tree gets good Fall foliage.  The branching and bark are very satisfying in the Winter too.  A four-season tree then?  Very possible, and very essential anywhere (Zone 5 - 9) it's hardy.

An unprepossessing opening picture, true.
It was a glorious bright-sunny day, so the interior seems dark dark dark. These are the pair of South-facing windows in our dining room; they're unusually large for an 18th C. house. With such low sills my guess is that they're a 19th C. addition. Whatever: They are a pleasure welcoming the Winter sun as well as the Summer view. I planted all kinds of plants to make that view worthwhile. Here's the show out the lower-left sash.
Boy do I love these plants. We'll look at most of them, and soon. Right now, the gold-leaved Japanese maple.
Yup, that's the color, and all season long: Glowing gold but not over the line into "Jeez, honey, where are my sunglasses?" yellow.

It's a Japanese maple too, mind you, so has that tribe's multi-trunked classy look to the branches and trunks. So yes, it's good even in Winter, when (alas, sniff, sigh) the leaves have fallen. But if we're lucky (I haven't been so far, but I live in faith), the Fall weather is such that just the tips of the leaves turn a cherry Fall red, leaving a round interior of each leaf still gold—hence the "Full Moon" of the common name. The tree is very slow growing, so buy the biggest you can afford. After a couple of decades, it might be only 18 feet tall. It's happy in amazing amounts of shade too; conversely, it handles full sun without scorching only if the soil is rich and it doesn't have to beg for water. I never water mine even though it's on the South side of the house and gets full West sun. So I guess my soil passes the test on both counts.
More on the companion plants later—and soon.

Wow, what foliage!
Not a chestnut, not a sassafras. It's a .... well, what IS it?
Firmiana simplex, a Chinese species very popular as a street-tree in Japan, and naturalized here the South. So it must be plenty calm even when there's heat, pollution, heavy soil, and the occasional lifted dog-leg. I've kept one in a pot for years for Summer display in Rhode Island. Here it was, a star of the shot in a Summer feature in Design New England. Click twice to see the photo full-size.

But here's a firmiana enjoying the cool life, right in the ground, in the East Village: Tompkins Square Park.
The green bark on young branches and even trunks is unique in sort-of-hardy trees.
The good news is that the tree is definitely and firmly Zone 7, which means NYC out to Long Island, plus the Cape and Islands and Southeastern Rhode Island. (Googling, I see it's also happy in the Missouri Botanic Garden. St. Louis is Zone 7? St. Louis is Zone 7! Who knew?)
I'll trial it in future Zone 7 projects. Hooray! But the downside of being Zone 7 is that Southwest Rhode Island isn't in it: The eastern tip of the North and South forks of Long Island keep the Gulf Stream at bay, alas. So my firmiana will stay in a pot, and hunker down, dormant and happy, in the basement all Winter. But a big potted firmiana—in Rhode Island, no less—is it's own statement. (And no, not because I let the tree grow bigger and bigger, with a huger and huger pot.) Why? Let's mozey back to those Japanese street scenes. (Oh I hope I have a picture from our Kyoto trip. I know this weekend!)
The trees are pruned back severely—you'd think that the entire city horticulture department had been taken over by the French.
And the trees were clearly handling the pruning well, too, in addition to all the other hard work of being alive in a hole in a sidewalk.
And so: being alive in a pot of Rhode Island dirt not that much smaller than the soil pocket for an entire street tree? Possible, very possible. And it's the pruning that makes it possible: As it limits the above-ground size of the tree, the below-ground part, the roots, are limited naturally.
It would be a thrill if the pruning also resulted in luxuriantly extra-large foliage, like it does when paulownia trees are pruned. To have these leaves twice and thrice as big as they are already?
That would be a performance indeed.

An enormous paulownia tree in full bloom is an astounding thing. Click on the photo twice to see it in all its huge full-size glory.
And to see the show in action, click the One-Minute Max here. The foot-high flower clusters point skyward, each with a score and more of two-inch lavender trumpets.
When the flowers fall to the ground, they keep their interest. This cardinal was scoping out the scene as long as I was, hopping back and forth, from the fallen flowers to nearby shrubs and then right back to the blossoms.
This bird is a florist of a sort. Who knew?

So far I grow only one "snakebark" maple, Acer pectinatum ssp. 'Forresti', which is one of the easiest in this heat-phobic, shade-happy tribe to establish. It keeps cool because it gets morning sun only, and it repays me handsomely:
Distinctive large leaves all Summer...
And you can see the white vertical striping on the trunk that leads to that "snakebark" name.

And in Winter—oh for heavens' sake: I don't have a picture of the stems in Winter, when they turn red! (I'll shoot it this Winter I promise.) But in Spring, I get the best of both seasons: The last remnants of the Winter red, the first green—eager fresh limey—of the new leaves.
And a bit closer:

What a comprehensive display, the color of the twigs juxtaposed with the color of the new leaves. The narrow thin-ness of the twigs joining the butterfly-wing pairs of the new leaves.
In color and shape both, leaves and twigs, it's a peak-of-the-year moment.