By Jim McCausland, Sunset Magazine

In tomorrow night's PBS special, The Botany of Desire, Michael Pollan tells how the genetic variability of apples allows them to fit neatly into a remarkably wide range of climates—and how people like Johnny Appleseed helped disperse them. 

One might add Kevin and Marty Hauser's names to that list. Raising fruit in Riverside, a short distance from California's first Washington Naval orange, they've experimented with more than 100 apple varieties, most of which are clearly out of zone in Southern California—and most of which are healthy and productive. 

So what's going on here? 

In part, the Hausers succeed because they experiment with apples that nobody's tried because they shouldn't have had a chance in mild climates. 'Wealthy' is an example. The first apple hardy enough to tolerate Minnesota's cold winters, it should demand a great deal of winter chill (total hours between 32° and 45° F) to set fruit, and it clearly wouldn't get that in Riverside. But in point of fact, how does it perform in the Hausers' orchard? Well enough to make Kevin's top 20 list.

The Hausers have also connected with a large network of apple growers to find out which apples have a good track record in warm climates. Kevin told me that 'Rome Beauty' grows in the flatlands of Indonesia, so it's no surprise that it does well in his own orchard.

In fact, he says, "I haven't found an apple that won't fruit here. But just because it fruits doesn't mean it's good." Apples that do well elsewhere ('Northern Spy' comes to mind) can be "horrible" in Riverside. And 'Braeburn' "fruits like crazy but rots from the inside out."

All this success doesn't mean that the Hausers are going to start a commercial orchard any time soon. In mild-winter climates, apples that have compact flowering and fruiting times in cold-winter climates tend to flower and fruit over a long period. That's bad for commercial growers, who want everything to fruit at once to reduce labor costs. But it is actually better for home gardeners, who like the season to stretch out a bit.

The Hausers do sell small grafted apple trees of many varieties to people who want to mimic their success where winters are balmy. Most are available on dwarfing rootstocks, so if you get the apple bug, you can, like them, grow 100 varieties on a city lot. Their mail-order operation is called Kuffel Creek Apple Nursery. And for a bite-by-bite account of many of the apples the Hausers grow, check out Kevin's blog.