Home & Garden Columns

Green Neighbors: How Are Things in Guacamole?

By Ron Sullivan
Tuesday September 25, 2007

You old hippies, you probably remember sticking an avocado pit on some arrangement of toothpicks over a jar of water to make it sprout. The tree, if it survived to that stage, made a decent houseplant when it wasn’t turning sickly yellow and dropping leaves and getting all etiolated like a wispy fishing rod because it was stuck in a dark corner and watered too seldom and/or too often by turns and potted in a bucket of backyard clay in the first place and the only fertilizer it ever got was when the cat peed in the pot.  

It’s a wonder any of us survived, isn’t it?  

Avocado as a species, Persea americana, is a survivor of sorts. Once upon a time it was native here, part of the Neotropical Tertiary geoflora along with others of our favorite gotta-try-it semitropicals and tropicals. We can grow some figs and palms here, and they used to be wildland plants.  

Of course, some of us are always pushing the boundaries, planting Buddha’s hand citrons alongside the more rational Meyer lemons. Some of us even get away with growing macadamias. Maybe global warming will let our descendants, if any, grow durians on the San Francisco Archipelago. But avocados are among the group with ancestral rights here. 

Time was, this tropical flora had a range extending as far north as the Arctic. The climate here was warmer, wetter than it is now, and the plants that lived here more like what we see farther south along coasts and riversides. Visit Costa Rica, for example, and you’ll see descendants of the trees and greenery whose fossils have turned up in places like Corral Hollow out past Livermore. Coral fossils have turned up near Walnut Creek, a place clearly underwater once and clearly warmer than now, and so have shells of sea critters that now come no closer than the Gulf of California. 

Things were drying up a bit in the Miocene, when we had gomphotheres and giraffish camels, sabertoothed not-quite-cats, and hyenalike dogs running around here. The neotropical trees were bearing smaller leaves and beginning their slow retreat southward, and the species that replaced them were tougher about water deprivation.  

That didn’t make them better houseplants, just by the way; consider how many live-oaks you’ve seen growing indoors, as opposed to those avocado relics. Most of our houseplants, from the spiderplants to the parlor palm, are tropical in origin, and tough in their own ways. The insides of human houses with or without central heating are still hard places for plants to make a living: dark, dry, weirdly tainted with stuff like natural gas that we animals usually tolerate better than they do.  

When you’re cruising guacamole recipes you might run across such oddities as the fact that jaguars like to eat avocados. I suppose I should ask Matt the Cat’s culinary opinion, but he’s hardly of a size to mess with a whole avo, tough hide and all. He’s kind of conservative anyway, not like our long-gone cat Dennis Moore who’d try anything including Doritos. A cat snatching and crunching a Dorito is one of those sights that suggest that we’re all capable of things far beyond what the more sloppy advocates of evolutionary psychology suggest are our fundamental biological boundaries. 

What is it with that big seed, anyway? Did avocados co-evolve with after-dinner gardeners for their seed distribution? Most local critters, including those jaguars, are no more capable of swallowing that seed whole and delivering it unscathed to a new home than old Dennis was of dunking a Dorito into guacamole and eating it without getting crumbs and smears all over the place. Avocados have been cultivated into bearing more of that lovely green stuff in their fruits, but the seeds aren’t bigger than their ancestors’.  

Back to those gomphotheres. They were elephantine in size and habits, and fat-rich avocado fruits would be gourmet tapas to them. They had fellow herbivores and omnivores jostling them at the buffet, including giant ground sloths like the one whose skeleton was turned up during excavation for the downtown Berkeley BART station. If you’re too dainty for a Shattuck or Telegraph Avenue with a few street people, be grateful you’re not sharing sidewalk space with a fur-clad and probably rarely-bathed mammal that stood 20 feet tall and weighed a few tons. It’s unlikely they ever said, “Please.”  

If you have a potted avocado and it’s leaning all over and looking sickly, you have nothing to lose by planting it outdoors somewhere. I knew one on north Berkeley that was regularly mistaken for a big old oak. It’s unlikely but possible that you’ll get good fruit from it; most of those commercial varieties don’t breed true from seed, but that big guy bore avos that were at least as good as a Fuerte. At the least, you’ll get a pretty shade tree, and I can promise you won’t have to worry about attracting giant ground sloths. 



Photograph by Ron Sullivan 

This great old avocado still lives in North Berkeley, but atrocious pruning is killing it.