Soil depth for wildflower planting

Hi,

I will be planting a small wildflower bed in spring, but I am concerned that my soil is not deep enough. I recently had my driveway block paved and as part of this process, there was a lot of stone and rock compacted together, to provide a solid foundation. This was done all over, including the space where the bed has been put in. Therefore, the soil is only about 20cm deep. Will wildflower seeds flourish here? Will their roots be able to penetrate through the compacted rock to the soil below? Or am I wasting my time planting wildflower seeds in this area?!

Phil.

 

20cm = 7.8 inches I believe. Sorry I still work in imperial. I don't see why they wouldn't grow, grass will grow in an area 4 inches deep. The only problem being, the area would have to be well watered during the summer months. You could raise the height of the bed above ground level to give the plants a better chance.

 

You'd be surprised at what can grow in 20cm of soil. I've got gravel areas on top of barely any soil and wild flowers self seed and germinate in that although they usually get pulled out as I don't want anything growing there.

 

That's great to know, thanks! I'd read that wildflower roots can grow several feet deep and I didn't know whether they can still function happily without the space to do this!

 

Where I used to live in Wales there was a Rowan Tree growing on top of a Telegraph pole. The only soil up there was wind blown slate dust and bird droppings