Sometimes it seems they’re out to get us. The same trees that shade our homes, add value to our neighborhoods and freshen our air regularly wreak havoc on our lives. Storms bring them crashing down on houses and power lines. They cost small fortunes when they’re planted, trimmed and, eventually, cut down. When they’re healthy, they choke us with their pollen. We ignore trees at our peril. Here are some acorns of wisdom that might help to keep the relationship cordial.