Browse Forums Landscape & Garden Design 1 Sep 14, 2015 3:41 pm I have a 9m long timber retaining wall, 600mm high built a few weeks ago behind which I would like to grow some hedges. Here is a pic of the area behind the wall: As you can see, it has not been completely backfilled. There is some gravel and socked ag pipe below for drainage at the base of the wall (less than 200mm of drainage material) The landscaper who built it was backfilling it with the excavated clay, but I requested him to stop, as the backfill was full of broken shale and gravel and I said I wanted to fill it with good soil. I have since learnt that the backfill above the gravel all the way up to 100mm below top of wall should be compacted soil with little organic matter. So that leaves only 100mm of good soil. How do people prep the soil above their retaining wall and plant things if so much of the soil needs to be compacted? I don't want to compromise the wall by cultivating the soil. What about if I cultivated the soil 40cm away from the top of the wall. Or do I just put 100mm good soil, then mound up some more good soil/compost etc and plant in the mound ? Would the compacted soil not create drainage issues for the plant ? I need to prep this bed asap. Any guidance will be much appreciated Re: Garden bed behind timber retaining wall 2Sep 15, 2015 1:20 pm just an update ... I heard back from my landscaper today. He assured me that given the height of the wall is only 600mm, there is no need to compact the backfill and that I should carry on and fill it up with garden mix or compost and plant away. He said backfill compaction becomes necessary when you are talking about walls 2m+. This is advice from an experienced, licenced landscaper, so I am going to go with it. Just to play it safe though, I am not going to disturb the soil within 30cm of the wall. The roots of my hedges can do that over time. By the way I will be planting either photinia or lilly pilly hedges. Are the roots invasive ? I have a driveway just behind this area. Still happy to hear from anyone who can add to or amend this advice . Ta. looks ok to me, round logs retaining walls are better than sleeper walls, more even preservative treatment and stronger since they include the whole tree and not just part… 1 2605 Thank you again Simeon.. I will call my certifier for that. Have a good day 4 5197 Old Home Restoration / Renovation Hi, just discovered all these junks left behind under the floor. Could any of these be asbestos? Best to leave as it is or clean up? Thank you for your thoughts 0 8070 |