If you are driving from the North, or from the M25, exit the M25 at junction 10 and head southbound for about 1 minute on the A3 towards Guildford (following the signs to Wisley RHS Gardens).
After 1 mile (approx) take the exit for Ripley and “Wisley. At the end of the slip road go all the way around the roundabout, back onto the A3 heading northbound. Stay in the left hand lane (ignore Mill Lane on your left). About 200 yards after entering the A3, turn left following the signs to RHS Wisley Gardens.