In Mediterranean climate regions, like ours, it is the cool season in which most plants are at their peak. (Daily Pilot / October 15, 2010)

I do my best every year about this time to remind local gardeners of the importance of fall gardening.

I can't say it much better than I did two years ago in this same column, so here it is again: Sit down. Don't get mad and don't turn the page quite yet. This isn't a misprint.

For local gardeners the mantra is "fall is spring."

Those three words form the foundation of successful gardening in Southern California.

Forget the calendar for a moment and read on. In Mediterranean climates, from a plant's point-of-view, there are really only two seasons: a cool season and a warm season. One season is for growing and the other is for resting.

Generally speaking, Orange County's cool season begins about now and wraps up sometime in April or May. Our warm season, on the other hand, occupies the rest of the next year, from about April or May through early fall.

In Mediterranean climate regions, like ours, it is the cool season in which most well-adapted plants are at their peak. In Southern California, the warm season is the time for rest and the cool season is the time for growth.

Even beginning gardeners usually grasp the idea of plants having a growing season and a resting season. But where locals often get confused is when they instinctively assume that the warm season is for growing and the cool season is for resting.

For beginning gardeners it's understandable if this "fall is spring" concept might seem just alien. Most of the world doesn't operate on our schedule. In most places, plants lose their leaves, stop growing, die back, go dormant or sleep in the cool season.

But not here. Ignore the winter-sleep, summer-grow gardening misinformation in the media; it's exactly opposite in Southern California. We're unique.

As evidence of our season, visit a garden in Chicago, Philadelphia, New York, Dallas, Kansas City or even Bakersfield or Fresno in the cool season. The gardens there are asleep; so are the native plants, the forests and the hillsides. In these climates, April and May is the time when plants are waking up, flowers are budding, trees are growing and gardeners are planting furiously. In these places, where a huge majority of gardeners live, "spring is spring."

So it's understandable that casual Orange County gardeners, especially those transplanted from afar, have such a difficult time grasping the concept that here "fall is spring."

It just makes sense. During the warm-season in Orange County our hillsides go to sleep, wildflowers disappear, canyonsides struggle and plantlife goes on hold, waiting for cooler weather and fall showers.

Conversely, observant gardeners will notice that it is during Orange County's cool season that plantlife awakens and hillsides and roadsides turn green and colorful. That's the natural system that has worked so perfectly in our Mediterranean climate for millions of years.

Given the opportunity, our local gardens would prefer to operate on this same cycle.

Orange County's Mediterranean climate provides rain in the winter and drought in the summer. Winter temperatures are mild here. Planting in the fall and early winter gives new plants the advantage of natural rainfall and mild temperatures. The cooler temperatures also make the activity of gardening more enjoyable for all of us.

In Orange County, most plants, when planted in the fall, rapidly grow underground. The novice or impatient gardener might underappreciate root growth, but the seasoned expert worships it.

There are exceptions to this local "fall is spring" scheme: the tropical plants in our gardens. Bananas, plumerias, elephant ears, avocados and similar plants that have come from warm, moist climates in the tropics are on a different cycle. Being from equatorial regions, tropical plants are not accustomed to a seasonal change in temperature or rainfall. These plants enjoy summer — our warm season — as long as the gardener supplies them with plenty of summer water. In fact, tropical plants don't know what winter is.

So, for local gardeners "fall is spring." This is spring. It starts right now. The season isn't over — it's just beginning.

RON VANDERHOFF is the nursery manager at Roger's Gardens in Corona del Mar.

Ask Ron

Question: Is it safe to plant sweet peas now?

Dineen

Newport Coast

Answer: Yes, this is prime time for planting sweet peas from seed. I prefer planting a blend of quick-blooming varieties along with traditional types. The quick-blooming varieties are usually identified as "Elegance" hybrids on seed racks, and with a little luck might begin blooming by the end of the year.

ASK RON your toughest gardening questions, and the expert nursery staff at Roger's Gardens will come up with an answer. Please include your name, phone number and city, and limit queries to 30 words or fewer. E-mail stumpthegardener@rogersgardens.com, or write to Plant Talk at Roger's Gardens, 2301 San Joaquin Hills Road, Corona del Mar, CA 92625.