I was consulting with a staging client last week, and she was lamenting that she wasn't able to put in her tomatoes this year because they were selling the house.  I asked her why not, and she said that she didn't think it would look good to buyers.  I didn't agree and here's why:

• if a garden bed is neat, clean, weeded and thriving - this makes the whole yard look good
• gardens are inviting - and promote that image of "I could live like this" that you want when selling the home
• backyard, urban 'homesteading' is super hot right now (I personally have chickens if you can imagine!)
• the majority of buyers, seeing fresh tomatoes and herbs growing in their own backyard can envision them as their own - and who doesn't like fresh tomatoes?
• a ready made garden bed can be a great selling feature - so many people want a garden but never seem to have the time or energy to create one

As long as the garden is well maintained and still leaves room in the yard for kids and dogs to romp, I say "go for it".  It may not appeal to every buyer but I suspect they'd be few and far between.  You may not be there to enjoy the bounty but your buyers will thank you!