Try building a tall fence around the garden with a speaker near the garden so when you see a deer approach the garden say "Hey get away freeloader" (or something like that), deers are known to be wary and somewhat frighten of human voices.
Or you can build a tall fence without the speaker.
Here are some site that are dedicated to repelling deers, and they are even devoted to good natural repellant.
http://www.deerscram.com/
http://www.deerout.com/
http://www.liquidfence.com/deer-combo.html?utm_source=hp&utm_medium=web&utm_campaign=combopacks
http://www.deerbusters.com/scaring-devices.html
http://www.deerbusters.com/deer-fence---virtually-invisible.html
http://www.critter-repellent.com/deer/deer-repellent.php
http://www.nottonight.com/
The list are endless, try going to Yahoo and type in "Deer Repellent". You'll get tons on information.
GOOD LUCK