If you’re a huge fan of Halloween, don’t miss the high-contrast, orange and black color palette now on display in the Marjorie McNeely Conservatory’s Sunken Garden. “Black is one of the most difficult flower colors to find,” says horticultural supervisor Paul Knuth, who used a mix of Halloween II and Mariposa Black pansies, and Sorbet Black Delight violas against a field of flaming orange and gold chrysanthemums to create a floral celebration of ZooBoo’s 30th anniversary during the first half of the Fall Flower Show. After ZooBoo takes its final bow at the end of October, the second half of the Flower Show will feature a palette of pink and black through November 26.