gap between fence and house side concrete

There is a gap(500mm deep and 600mm wide) between the timber fence and concrete slab at the side of the house as shown in pic. The concreter asked us not to remove the gravel from the sides(its slopy) .I wanted to place planter boxes in that area . Any suggestions how i could achieve it.any ideas would be really helpful.

(we thought of putting sleeper boards, filling up the area till concrete level (to avoid contact with fence and also to avoid adding load to fence) and then place planters on top of it..not sure if this is ok

 

I would backfill it with woodchips or similar and place planter boxes on top.

 

As that is the only place for water to run off from the concrete path it's going to take some thinking to get the right answer.

Maybe fill with some extra gravel then planter boxes on legs so that water can still get in?

 

The fence shouldnt have been installed to earth level on that low side. There should have been a retaining wall to raise the level and the fence ontop of that. If you fill to the fence you will create a fence issue (rot) and fixing the fence later will be a problem as the fence will be buried. Then there is a need for some drainage along the path edge.

If I were doing it I would consider a supported timber retaining backing just off the fence (50-70mm) up to height of concrete. Fill with quality soil and turf it. Or consider something of a garden bed with retaining support behind it. Consider ridgi or similar conc retaining wall system but they are very expensive by the lineal metre even to a low height (2 panels high ?) + steel + concrete etc. Timber system etc may be cheaper but seems like a lot of pine.

That fence seems to have a distance between posts. The lower horizontal rail has some intermediate vertical timbers that arent even posts. They just float there and seem to have limited value. It may not be built to last.

 

its quite an easy fix. Hardwood sleeper against fence with maybe a small hardwood post or sleeper off-cut in between to stop the weight of the new soil pushing the fence out(this can be kept below the top of sleeper so it’s not seen). Personally I’d fill the void with a drainage product to help absorb any heavy rainfall. If it’s not an area that’s seen put some sandstone decorative pebble (means no future replacing as with mulch) on top which will assist the drainage. If you want plants perhaps do away with the drainage and use a good plantmix soil instead. Weed matting will help keep it low maintenance.