"Corporate interest is definitely growing," Mr. Nelson says. A few of the corporate sponsors include:
The car-rental company recently celebrated its 50th anniversary with a pledge of $50 million to the National Arbor Day Foundation to plant 50 million trees in national forests over 50 years.
Home Depot Foundation:
The retailer's foundation has pledged to plant 10,000 trees in 10 cities this year, its second year of tree-planting initiatives.
The hotel chain is giving away trees to Americans who pledge to plant them. Doubletree will match every "double-tree" Pledge to Plant Promise with two trees donated to U.S. forests as part of reforestation projects.
Frito-Lay North America:
Last year it planted 100,000 trees -- 75,000 in national forests, with the rest going to nonprofit organizations that won approval. This year it plans to triple its pledge to 300,000.
The financial provider will plant one tree for every customer who enrolls in its paperless-transactions program by the end of the year. It is partnering with the U.S. Forest Service to plant the trees in national forests.