Wat Pho Hom was established around 1819 AD on the premises of a former temple of the Ayutthayan era. The monastery received its boundary stones three years later in 1822 AD.
The temple was named after a old large Bodhi tree in its location. When the tree started to bud it shed a fragrant smell, hence the name of the monastery. 
The Bodhi tree or Ton Pho (Ficus Religiosa) is the sacred fig tree under which the Lord Buddha was sitting when he received his enlightenment. The tree is found in most of the temple premises, but is not grown in the compound of houses. The Bo tree in the temple is usually a tall shady tree, around which people sometimes wrap a yellow robe in the same manner as they dress a Buddha image with a yellow cloth. Some people place bamboo poles, trimmed and whitewashed, as supports to the holy tree. In the old days cowry shells used as token money, were inserted inside the bamboo poles. Poor people would bury the bones and ashes of their dear ones near the root of the Bo tree so that they may be near the holy symbol of the Lord Buddha. 
The monastery is situated in Geo Coord: 14° 25' 11.84" N, 100° 32' 44.50" E.
 http://www.watkhok.com - retrieved 21 December 2012.  Some Siamese Superstitions about trees and plants - Phya Anuman Rajadhon - JSS Vol 49.1 - 1961 - page 60.
Text & photographs by Tricky Vandenberg - January 2013