"Look." says Ann Marie. "Those redwoods have a huge amount of brown on them too."

We are in Tilden Park, just east of Berkeley, just over the first range of hills separating us from the Pacific Ocean. And the redwood trees do, indeed, have a lot of brown--a lot of dead branches--maybe one in ten branches is dead.

We worry about this because the builder and previous owner of our house planted some twenty-five redwood trees on the property about eighteen years ago. Some of these guys are now huge--seventy feet tall. On is dead: it grew to twenty feet and then joined the choir invisible. The rest are of varying heights (but fifty feet is a good guess as an average).

The problem is that this isn't redwood tree habitat: the last redwood tree grew here at least twelve thousand years ago. It gets very dry: it doesn't rain at all from May to November, our creek dries up by the end of June, and the spring at the northeast end of our property is now turning into a patch of damp mud, and will stay that way until the winter rains come.

And so, in the summer, large parts of our redwoods turn brown. Should we water them? I've been told that a full-grown redwood sucks up and respires 50 gallons of water a day.

What Ann Marie is telling me is that this is a common disease of Bay Area redwoods in the summer. It's true that these trees aren't healthy--and in a full-fledged Darwinian contest they probably wouldn't do too well. But we've put our thumbs on the scale because we like the way they look. Hence the extension of the coast redwood range to places like Tilden Park, and my front yard.