From Bangkok by bus:
Bangkok′s new and modern Southern Bus Terminal, known as Sai Tai Taling Chan or Sai Tai Mai, is on Phutthamonthon Soi 1 in Thonburi on the western side of the Chao Praya River. It is a bit difficult to get to but bus no. 511 will take you there from Democracy monument. It is easily identified by the S.C.Plaza building when entering the bus terminal.
Different types (24, 32, 40, 50 seaters) of air-conditioned buses depart here for southern Thailand. Take a bus bound for Surat Thani or Koh Samui (no. 991, 991-1), Nakhon Si Thammarat (no. 981) or Hat Yai (no. 992, 992-1) and ask to be let off at Suan Mokkh; buses will either let you off directly in front (km post 135) or at the nearby petrol station. Most buses going to Phuket (no. 949) will take that route as well.
If you book your journey in advance, and it is worth it during peak season and Thai holiday periods, you must go to the bus station to purchase your ticket. If you buy from a travel shop, you will probably end up on a tourist bus and may not get the usual high standard of the national buses. Be especially careful with private buses departing from the Khao San Road area as theft has been reported repeatedly on these buses.
The journey from Bangkok takes about 8 to 10 hours, so a good bus is worth the effort of going to the bus station in advance to book.
More information regarding travelling by bus (the English version is not working yet) is available at:
Surat Thani airport is about 27km south of Suan Mokkh and 2km west of the highway. It is possible to catch a taxi at the airport (approx. 500 baht*) or public transport at the airport gate at the highway (approx. 35 baht*) directly to Suan Mokkh without having to go into Surat Thani. It may take up to 1 hour to cover this distance by public transport. Public transport will cease around 3.30pm.
* Prices are given as a guide and may not be accurate, changing without warning. It is your responsibility to check prices before you travel to be sure you are willing to pay prices being charged.