First, though we see it here all the time, recognize that using a fence as a retaining wall is a bad practice that, at the very least, tends to be unhealthy for the fence. It is best not to do this if there is any way to avoid it. If you want recommendations for other ways of handling the problem, submit a picture (not a close-up) that illustrates the conditions. You might also explain why you think it's necessary to raise the grade at the fence.

It's a lot healthier for the fence to dig down and create a well-prepared groundlevel bed in front of the fence. Closely spaced plantings will quickly obscure the lower part of the fence without damaging it.

Fence area: new fence is up, but bed hasn't been dug yet.
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A recent photo:
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