Fiery Colors
Colorful Predictions
As leaves are just starting to color up, the question is, “Will the autumn leaf show be good this year?” First off, whether or not it’s good, global warming has pushed showtime forward a bit each year. Around here, the peak of the show used to be the middle of October; nowadays it’s the third week in October.
Japanese and sugar maples
Back to predicting how good the show will be this year . . . Throughout summer and into autumn most leaves are, of course, green, which is from chlorophyll. Chlorophyll must be continually synthesized for a leaf to stay green. The shorter days and lowering sun of waning summer are what trigger leaves to stop producing it, letting other pigments lurking there out of hiding.
The yellow and orange colors of leaves are always lurking there, thanks to carotenoid pigments, which help chlorophyll do its job of harvesting sunlight to convert into plant energy. I offer thanks to carotenoids for the especially warm, yellow glow they give to gingko, aspen, hickory, and birch leaves.
Gingko
Tannins are another pigment, actually metabolic wastes, that all summer are hidden by chlorophyll. Their contribution to the fall palette are the season’s subdued browns, notable in some oaks and enriching the yellow of beeches.
Because leaves harbor carotenoids and tannins all summer long, nothing particular about autumn weather should either intensify or subdue their autumn show. The only glitch could be an early, hard freeze that occurs while leaves are still chock full of chlorophyll. In that case, cell workings come screeching to a halt and all that’s left are frozen, green leaves that eventually drop without any fanfare.
Autumn color also spills out reds and purples, most evident in red maples and some sugar maples, scarlet oak, sourwood, blueberry, and winged euonymus. Those reds and purples come from yet another pigment, anthocyanins. Except for trees like ‘Purple Fountain’ beech and ‘Royal Purple’ smokebush, whose leaves unfold dusky red right from the get go in spring and remain so all season long, in most leaves anthocyanins do not begin to develop until autumn.
Anthocyanin formation requires sugars, so anything that we or the weather does to promote sugar accumulation in autumn will increase anthocyanin levels in leaves. Ideal weather conditions for sugar accumulation are warm, sunny days to maximize photosynthesis, and cool, but not frigid, nights to minimize nighttime burning up of accumulated sugars.
The many cloudy and rainy days for the past weeks don’t bode well for a great autumn show of leaf color. Less red because less anthocyanin is formed, and any that does form is diluted.
Our Hand in the Color Palette
Weather plays its part in autumn color but we can also have a hand in its development. One way is to ratchet up the reds and purples to make sure that leaves bask in light. I plant a tree where light is adequate (for that species) and, as necessary, prune so that branches don’t shade each other. Street lights don’t count as light, and actually have a negative effect, disrupting the signal that days are getting shorter and it’s time to slow chlorophyll production.
We also can ramp up the autumn show by planting trees genetically programmed for good autumn color. Among the most colorful-leaved trees and shrubs—which, besides those previously mentioned, include goldenrain tree, hickory, ironwood, black tupelo, and fothergilla—individuals within each species might pack a bigger wow than the others. Hence the spicebush variety ‘Rubra’, brick red in fall, or ‘Wright Brothers’ sugar maple, whose leaves become a mottling of gold, pink, orange, and scarlet.
Admittedly, the weather trumps (sorry) all.
(For more about some of the science going on behind the scenes in your garden, and how to put it to practical use, see my new book, The Ever Curious Gardener: Using A Little Natural Science for a Much Better Garden, from which the above is adapted.)
A Brainy Orange
There’s another orange in the garden this autumn, and it’s not in the leaves or the fruit — the hardy orange — about which I recently wrote. It’s the osage orange (Maclura pomifera).
I grew my two trees from seeds extracted from a local osage orange I found on the ground. Each tree is about 25 feet tall and intimidating for their large, mean thorns. Trees are either male or female, so I lucked out, ending up with one of each, allowing the female to bear.
Why would I plant such a tree? For interest: This native of the midwest was, thanks to its thorns, a predecessor of barbed wire for containing livestock; also the primo wood sought after by Native Americans for their bows; and the wood is among the most rot-resistant of any tree.
The softball-sized fruit also is very interesting, with all its convolutions looking something like a green brain. Although related to fig and mulberry, it’s not at all edible. The fruit is claimed, without substantiation, to repel insects and spiders in and around homes.
New York Grown Oranges!
Yes, A True Citrus
Oranges? In New York, planted outdoors in the ground? Yes, I have them ripening on the branches now. No matter if they ripen thoroughly or not because, although they are true oranges, delicious flavor is not one of their assets. It’s still a plant well worth growing.
The plant is the aptly named “hardy orange,” actually a true citrus species, Citrus trifoliata. (Previously, hardy orange was a citrus relative; botanists recently moved it to the Citrus genus from the closely related Poncirus genus.)
Mostly I planted hardy orange for its stems, whose show is at the same time intimidating, interesting, and decorative. Stems of the variety that I grow, Flying Dragon, twist and contort every which way, and then add to the show with large, recurving thorns. Stems and thorns are forest green, even as they age, and remain so all through winter to make the plant especially decorative when leafless.
I would have planted Flying Dragon hardy orange just for its stems. But adding to the show, in spring are white flowers — citrus flowers — that are fragrant just like those of oranges and lemons. On my plant, at least, they’re smaller with commensurately less fragrance.
This year, this month, Flying Dragon has presented yet another attractive face. Its leaves are preparing to drop by turning a pinkish crimson. This color, developing for now on leaves towards the ends of the topmost branches contrasts nicely with the still forest green leaves and the few fruits starting to yellow.
The problem with the fruits, gustatorily, is that they’re not very juicy, and they are very tart, somewhat bitter, and seedy. Still, they can be used to add a bit of home-grown citrus flavor to an -ade (Flying Dragonade?), fish, etc.
I Plant A Seed
New hardy orange plants are easy to raise from seed. The most important ingredient, as with other citrus, is not letting the seeds dry out once extracted from the fruit.
With most plants, you don’t get an exact replica of the mother plant in seedlings. Plant a McIntosh apple seed and the resulting tree will not bear McIntosh apples. (Just as you are not a genetic replica of your mother.) It depends on what pollinated the mother tree and how the chromosomes sorted out. Even though peaches are self-pollinating, the offspring of a Redhaven peach won’t bear Redhaven peaches.
Plant a seed of Flying Dragon hardy orange (or some other citrus varieties, in general), and you could get more Flying Dragons, exact replicas of the mother plant. That’s because citrus are among the few plants that exhibit apomixis, that is, seeds within the fruits that develop from only mother plant tissue.
Other plants that also bear apomictic seeds are some species of onion and dandelion. Some coneflowers, apples, and raspberries also bear apomictic seeds, but only if the flowers are pollinated — even though the pollen does not insinuate itself into the apomictic seed’s genetics.
Not all the seeds within a Flying Dragon fruit are apomictic. Hence, not all will grow to become Flying Dragons.
The seedling on right is probably apomictic
Further complicating matters, some seeds can develop into more than one seedling! And some of those seedlings growing from that one seed might be apomictic while others will be run-of-the-mill.
None of these complications interferes with my propagating Flying Dragons from seed. The contorted stems and recurved thorns are so distinctive that it’s easy to tell the Flying Dragons from the others. Apomictic seedlings also are generally more vigorous than sexually-produced seedlings.
Not Everyone’s A Fan
Southerners are not nearly as enamored with hardy orange as I am . The hardiness, the thorns, and the seeds’ enthusiasm to sprout make the plants a threat down there, where the shrubs grow from 8 to 15 feet tall.
Hardy oranges were introduced into the south about 150 years ago, possibly to contain livestock. There, the plants have spread to woodlands, forest edges, and fencerows to shade out native plants. The lack of affection for the plant might be summed up in a quote from a Texas publication stating that hardy orange “does respond well to bulldozing.”
While bemoaning not being able to grow southern magnolia, gardenia, camellia, and crape myrtle this far north, I am thankful for being able to grow hardy orange without any danger.
Happy “Nose Twist,” Sad Tomatoes
Nasturtium In Its Element
It’s nice to see that at least someone or thing enjoys the current cool, wet weather. My eight ducks, for instance. As I open the door to “duckingham palace,” each duck pads out onto the slurpy ground as happy as a lark (a lark on a sunny day, I assume). 
Also enjoying this awful weather are the oat cover crops that I’ve sown in some of my vegetable beds. The oats are especially lush and green, as is your and my lawn grass. The same goes for beds I recently planted with lettuce, radishes, arugula, turnips and other cool weather vegetables.
Nasturtium flowers, which I planted back in May, went hardly noticed all season long. But now they are lush, their red flowers boldly staring out against the background of their round disks of bluish green leaves.
The plants’ present prominence comes, first, from the weather. Native from the cool highlands of Mexico down into Chile and Argentina, the plants feel right at home, and show it with their luxuriant growth, when I’m beginning to feel chilly. They also have come into prominence because some of their neighboring plants — marigolds, cucumbers, and tomatoes, for example — are waning.
Nasturtium offers a lot of bang for the buck, so for many years, each May, I’ve dropped the seeds into holes I poke into the ground. Mostly I plant them near my garden gates but also, some years, along the wide, main path at the head of each of the vegetable beds. The latter planting was an emulation of painter Claude Monet’s well-known nasturtium plantings that softened the wide path beneath his long arbor. The plant isn’t really a climber, but may be called a clamberer; that’s how it makes its way partway up nearby gates and wire fences.
Nasturtium seeds germinate readily once the soil warms sufficiently and then are care-free all summer long. The large size of the seeds and their quick germination make them fun for children to plant and watch.
Sometimes the plants are so care-free as to need some discipline. The ones I planted along my path required pruning to keep them from meeting in the middle and obliterating the path.
Nasturtium offers more than just beauty. All parts of the plant are edible. The leaves add a pungent pizazz to a sandwich, the flowers add pizazz and eye appeal to a salad. The immature seeds can be pickled as stand-ins for capers. One nasturtium species, called mashua in some parts of the world, is a perennial producing edible tubers. This one is an actual climber rather than a clamberer.
And Now, for Nose Twist
Nasturtium got its common name because of its similarity in taste to watercress, which is botanically Nasturtium officiale. The word “nasturtium” comes from the Latin words nasus, meaning “nose,” and torqueum, meaning “twist,” which is what the peppery flavor of watercress or nasturtium does.
Despite one plant sharing its common name with the botanical name of the other, nasturtium and watercress are not in the same family. They do, however, share certain flavor profiles (which is why both are nose twisters). So much so that the cabbage white butterfly will feed on nasturtium as well as its namesake, cabbage. But not with great enthusiasm. The caterpillar phase of the cabbage white butterfly will only feed on nasturtium if it did so from birth; try feeding it to the second or third instar of this insect, and it would rather starve, literally!
The genus for nasturtium is Tropaeolum, the “trop” part related to the word “trophy.” Founder of plant taxonomy, Carl von Linnaeus, assigned this name because the clambering flowers and leaves reminded him of the helmets and shields of the vanquished which were draped on tree branches following battles in his day.
Tomatoes Exit
In contrast to the nasturtiums, my tomato plants are not at all happy with the weather now — or for much of this summer. Humid conditions have fostered diseases, the usual leaf spotting diseases (early blight, late blight, and septoria leaf spot) as well as anthracnose.
Anthracnose is particularly vexing because apparently sound tomatoes develop the sunken, rotting lesions from this disease after only a day or so on the kitchen counter.
A thorough cleanup of all tomato leaves, stems, and fruits, covering the ground with compost, and moving tomato plantings to new locations should help limit disease next year. Also, wearing red shoes and clicking my heals together three times before planting might help.
The passing of tomatoes isn’t all that bad because they don’t taste that good in this weather. And we do have a reasonable amount broadcasting their richness through the sparkling clear glass of canning jars.
