Question
I plan on building a raised garden bed 2-3' high and 2-3' wide against a chain linked/cyclone fence.  I am going to use stones for the front part of it.  What can I use for the back part of the bed to hold the dirt in and prevent it from falling out the chain link fence.  Presently I have some old wood planks set up for the back, but after researching, I am worried about rot.  Can I use this wood or is there something else I may use?  I do not want to build out from the fence (at least not too far) because I have my children's playground set not too far from there.  I am building this bed because the soil against that fence is not very good and i cannot get grass to grow there.

Answer
Hi luis. Thanks for the question. Unfortunately I have rarely dealt with this issue, as I try to steer people away from building "up" against fences. There really is no great solution to this, that is why it is not done very often.

Most people will use a pressure treated lumber which will last longer than regular lumber. Cedar will also last a little longer. I have also seen people staple liners to the backing of the wooden boards but see this can actually hold in moisture between the barrier and the wood.

I know you said that you can't build out very far, but can you use the same stone for the back as the front?
Another option is to dig out some of the poor soil that you have already and build the wall lower. Basically, you will be splitting the height difference between digging down and building up for your proper soil depth. Your wall will be 1.5 ft high in this case and may look better than a 3 ft wall.
One thing to keep in mind about designing, is proportion.
Keep the size of the features in line with the yard itself. (That includes height) it will give your design a better balance.
Do you have someone next door that may be upset about looking at the back side of boards up against the chain link fence?
Have you considered working with the them? Maybe there is another option that would satisfy you both?
I hope this gives you some more food for thought?
Good luck with your project.
I would like to see the result as well.
Kevin