Natural Perspectives:

The autumnal equinox is Monday. That’s when day and night are of equal length. It’s the beginning of fall. The sun has headed south for the winter, along with our terns and swallows.

The sun reached its farthest northern point in the sky in June, at the summer solstice. It’s been tracking back south since then and is pretty much directly over the equator at the autumnal equinox. Vic tells me this isn’t a very Copernican — or is it Galilean — view. We all know that the earth tilts and that’s why the sun appears to move north and south, causing a change in season. But cold hard science takes out all of the romance.

Signs that summer is fading into fall are all around us. In Central Park, mallard drakes are molting from drab brown into their colorful breeding plumage of green heads and russet chests. The drakes will pair bond with hen mallards soon, and will need bright feathers for maximum allure.

At Bolsa Chica, the majority of the terns have flown south. Caspian and Forster’s terns remain through winter, but the huge, raucous flocks of elegant terns are gone, along with the quieter California least terns. However, black skimmers are surprisingly late nesters and are just now fledging their young.

Taking the place of summer’s tern colonies are throngs of wintering shorebirds, recently returned from Alaska and Canada. Their numbers will continue to swell over the next few weeks as waves of migrants either travel through to points south, or settle here in Orange County for the winter.

The little fish that hatched over summer and survived the dives of foraging terns will have time to grow over the winter. Unless they’re eaten by bigger fish. Or caught by our winter visitors such as mergansers and grebes. It’s a rough life out there in the wild.

Some of Bolsa Chica’s denizens will head for deeper water as the shallow bay cools down. While bays are warmer than the open ocean in the summer, and make great nurseries for marine life, they cool off disproportionately in winter. Our stingrays, sharks and sea hares head for the depths at this time of year. We rarely see them during the winter months.

Coastal Southern California lacks the brilliant autumn colors that characterize eastern and midwestern hardwood forests, but we have our own signs of fall. The leaves on the sycamores in Central Park are transitioning from the deep, dark greens of late summer into the crisp dry browns of autumn.

A few leaves are falling already. If you have liquid amber trees in your neighborhood, as we do, you’ll see brilliant scarlets, burgundies and yellows later in the season. But for real fall color, you’ll have to head up into the San Bernardino Mountains or the Sierras to see aspens and mountain mahoganies put on their autumn coats.

We see seasonal changes even in our backyard. The cheerful yellow sunflowers that brightened our garden in July and August are looking quite tired. Their once-lush leaves are now crumpled and dry, and their brown heads nod low on bent stalks. Goldfinches and house finches peck at the heads, extracting oil-rich seeds.

Golden garden spiders spin their beautiful orb webs every evening. Sometimes drama plays out in the microcosm of our garden as a paper wasp snatches a spider from its web and devours it. Anna’s and Allen’s hummingbirds check the webs daily to raid any insects that might have been snared. While these spiders were tiny in summer, the ones that survived predation by wasps and depredation by hummingbirds have grown quite fat and large on the insects that flit through our pesticide-free yard. Soon the females will mate, lay eggs and die. Next spring will bring another generation of these lovely and harmless spiders, and once again we’ll enjoy watching them spin their silken webs.

Some of the summer vegetables in our garden are hanging on into fall. After languishing all summer, the eggplants and cucumbers are just now coming into production. But the summer squash are nearly all gone. We may get a few more golden zucchinis and kuta squash if we’re lucky. Or, from Vic’s point of view, if we’re unlucky. The bulk of the tomato harvest is over as well, but a late planting of Silver Queen corn is promising a few tasty ears. It remains to be seen if the corn will feed us or the raccoons.

We planted a number of fruit trees two years ago. They’re still young and thus are not producing much. Our Santa Rosa plums, Babcock peaches and Panamint nectarines made a large and memorable fruit salad for our Fourth of July barbecue. But without enough of these stone fruits to make jam this year, their sweet, juicy flavor is but a fading summer memory. However, our Granny Smith apple tree has outdone itself this year, with huge apples that are nearly ready to go into sumptuous, streusel-topped pies.

With the heat of summer dissipating, we’re more willing to spend time in the kitchen baking. The August aroma of simmering tomato sauce loaded with homegrown oregano and garlic gives way to the cinnamon smells of September as we bake butternut squash and pumpkin bread, and serve them with cider.

The autumnal equinox may signal the end of summer, but it certainly doesn’t mean the end of Southern California’s garden season. Mid- to late-September is a perfect time to start a winter vegetable garden.

Next week, we’ll show you how.

VIC LEIPZIG and LOU MURRAY are Huntington Beach residents and environmentalists. They can be reached at vicleipzig@aol.com.