The Nash Block, also known as the McKesson-Robbins Warehouse and currently as The Greenhouse, is located at 902-912 Farnam Street in Omaha, Nebraska.

Designed by Thomas R. Kimball and built in 1907, the building is the last remnant of Downtown Omaha's Jobbers Canyon.

It was named an Omaha Landmark in 1978, and was listed on the National Register of Historic Places in 1985.

Thomas R. Kimball designed the building as the first factory-warehouse in Omaha with the modern fire protection elements, including brick enclosures for stairs and elevators, fireproof doors and an automatic sprinkler system.

The M. E. Smith Company was the largest and most important dry goods firm in Omaha at the turn of the century.