November 8, 2026. In connection with Texas Arbor Day — which is celebrated annually in November, because it is the best time to plant trees in the state — the Houston Botanic Garden introduces “Standing Tall: A Texas Tree Festival” to celebrate the amazing native trees of Texas. This full-day, family-friendly event will feature a kids’ zone with tree-themed crafts and activities, guided walks to view and learn more about native trees around the Garden’s 132-acre site, a marketplace including food vendors, live entertainment, and more.