Sunnyca, thanks for the response. You make good points. No, there's nothing wrong with the ground near the fence. We wanted a short raised bed for 2 reasons: one to give us an excuse to build a retaining wall for aesthetic purposes, and the other is to give a headstart of a foot or 2 for the plants and vines that we hope will help a little with privacy. Building a short wall for aesthetic purposes and not filling it with some dirt to raise the level of the bed might be problematic because of the shade the wall would cast over young plants and also because gardening along the fence would requite a lot of bending.

I'm certainly worried about ruining the fence, so your points are making me reconsider my plans. I need to look into the possibility of putting the back boards a 4-5 inches from the fence. Hopefully it won't look bad.

Will the 4-5 inches between the raised bed and the fence be accessible (behind the vines and plants you're planting)? You may need to weed that narrow area, or spray with herbicide (without damaging the vines and plants in the bed) or perhaps a pre-emergent.

How about a berm? This will give you extra height and visual interest without destroying your fence.

Putting beds along the perimeter is like a human reflex, but doesn't always make the most pleasing design for many reasons including those raised by Sunny. Also, if you search "fence" or maybe "narrow bed" in this forum, you'll find some discussions of planting along fences, not always the best growing condition for the plants. Finally, it is really really nice to be able to tend to beds from the back.

If you have some space to work with, I would lay a path of paving slabs, maybe 24 inch wide ones, along the fence, and put your raised bed in front of that.

KarinL

If you are determined to build a raised bed immediately adjacent the existing fence, to 2 foot height, you will need to engineer it to withstand the additional pressure of all that wet dirt, as well as build it so you don't rot out the redwood fence boards. I'd suggest installing 2.5 inch diameter metal fence posts(the type used for fence posts on cyclone fencing), immediately adjacent the fence at 6 foot on center spacing with 18 inch deep by 9 inch diameter concrete footings, and then bolting pressure treated doug fir 2 x 12's to the poles, and lastly, using a plastic liner like bamboo rhizome barrier to form a moisture shield at the inside of the wall, before you backfill with soil.

This type of construction would be long lasting and relatively cheaper to install than using concrete block and footings at the back side. You should not underestimate the weight that 2 foot of wet soil exerts as an outward pressure on walls, nor the damage that constant wetness can do on wood fencing.

bahia,

Why do you recommend a plastic liner as a moisture shield on the inside of the wall? The blocks that will make the wall are made of concrete, so moisture damage isn't something to worry about. Or am I missing something?

As for the barrier between the wall and the fence, is there a reason the posts won't survive if simply staked into the ground?

Moisture barrier is recommended against the wood portion of the retaining wall adjacent the fence. I wouldn't recommend attaching the retaining wall boards directly to the existing posts, as you can't assume that the footings are sufficient to handle the additional pressure, and a separate wall makes it easier to fix/repair/replace the wood fence when needed. If the fence and wall were being designed and installed at the same time, this would make a difference as to how it could be detailed and built.

You've asked for opinions/advice on how others would do this who have experience with this type of work, I've given you mine.

bakaroni:
One more thing to consider, if you end up with a narrow space that can't be cleaned out between the existing fence and whatever you construct: What will happen to any leaves that collect in that narrow space? Will they be visible to people on the other side of the fence? Will they pack down, hold moisture, rot, and eventually damage the fence?

Whatever kind of raised bed you build, it might be good to have a moisture barrier between the side walls and the soil inside it, to help retain moisture . . . especially if you're in a dry region. Soil in raised beds tends to dry out faster than soil below ground level if the material you use for the walls is capable of absorbing moisture.

Raised beds block the flow of surface runoff if they interupt it. You may wind up with a puddle (or your neighbor might.

It can probably be presumed that the lot grading for the subdivision is such that lots are all graded to drain independently out to the street on each individual property, so that creating a drainage problem for a neighbor is not likely, but then again, this lot could have slopes and drainage across lot lines, in which case interruption of flow is an issue. My understanding from another post by the OP on this same garden was that theot was flat, and the intent to build raised beds was more for aesthetics as well as making vegetable raised beds that would have improved soil conditions and be easier to work.

The idea of a french drain as sketched out by the OP, which seemed to form a circle at the base of the proposed raised beds but didn't actually connect with anything, didn't seem to make much sense in terms of actually solving a drainage problem, in fact, if the lot is flat, they would seem to have been superfluous to solving the problem of a wet crawl space under the house, which sounds more like it was related to roof downspouts unconnected to drain lines to take it away from the house.

I had originally understood the back of the lot to have the lot behind it at a higher grade with a slope beyond the proposed raised beds, but the sketches did not appear to support that line of supposition.

In any case, I'd suggest that the OP either hire a competent landscape architect or designer/contractor to give him more informed advice on solving his problems and avoiding unnecessary expense or useless construction, or read up more to become better informed about landscape construction and particularly drainage concerns as they would pertain to his Fremont location.

As it is, the questions have been too general to give truly informed advice, and not enough information has been supplied to really address all the potential concerns. I'd hope that these discussions have been sufficient to alert the OP that he needs to either hire some informed help, or get up to speed with the information needed to make the best decisions on how to proceed. There are definitely times when it saves money and expense to hire expertise...

This is inconsiderate to the dividing fence and your neighbour. all retaining should be well away from the dividing fence