[Note: Verdance clients originally received this article at the beginning of this month, as part of our free monthly newsletter on gardens and gardening. To subscribe to the newsletter yourself, please register at verdancedesign.com.]
Have you noticed yet? Nights are cooling off, leaves are showing red, and — my favorite — the sunlight is softer and more golden. Autumn is here! The equinox occurs on Sept. 22, and then nights will outlast days until March.
I'm often asked, is fall the best time to plant in the Bay Area or not? While I wouldn't delay a project by 6 or 9 months just for the season's sake, it definitely beats summer: plants are less stressed, need less water, and have more time to develop healthy roots before next year's heat.
Another good reason to plant over the next few months is that nurseries have terrific inventory now. Sure, there are some sun-baked has-beens on the racks, the runts that never quite endeared themselves to other gardeners, but lots more are in fine shape, a little mildewy or root-bound at worst. (And frankly, I even view the runts as opportunities, tests of my horticultural mettle.)
Of course, if you're looking to add a little fall color to your landscape, now's also the time to shop. Look for Chinese pistache, crape myrtle, sour gum, oakleaf hydrangea, Boston ivy and Virginia creeper, Japanese and other maples, and ornamental grapes, cherries and pears. And don't forget about plants with interesting berries or seeds: grass plumes positively glow when backlit by the rich autumn sun. (If you would like ideas on what or where to plant for best effect in your garden, just let me know.)
Since those fiery reds, oranges and yellows actually only appear in the absence of green clorophyll — and since clorophyll production typically stops as plants retreat into winter dormancy — you can encourage autumn colors by sending signals now that summer is over. Stop watering established plants (short of wilting them) to discourage new growth; and locate new trees, shrubs or vines in full sun for the most extreme temperature changes as nights get colder.
One class of plants that clearly benefits from fall planting, although they're not much for fall color, is California natives. These take advantage of the winter rains to develop robust root systems that can endure our long dry summers. I'll say more about natives in future posts, but for now check the California Native Plant Society for lists of botanic gardens, nurseries, and plant sales — yet another reason to love autumn in the Bay Area.