Although south-facing houses and gardens are usually desirable, there are other considerations to bear in mind. If there are houses or trees obscuring the sun, for example, you might not see the benefits of a southerly orientation as your garden will be shady regardless. Likewise, if the view is better from your house or garden when facing north, west or easterly, the advantages of a different orientation can outweigh the benefits of the additional sunlight.
If in doubt, make sure you do a drive-by of your new house at different times of day, so you can see which areas are sunny and which are shady in the morning, afternoon and evening. You could even use the compass app on your smartphone to see exactly which way the garden faces and get more of an understanding of how much light the property gets throughout the day.