Any advise welcome
Poly-anthus Posts: 142
We have a retaining wall in our back garden made from railway sleepers. The water from the top part seeps down under the wall. I have cut out several little beds at the bottom of the wall, but as we have horrendous clay soil with awful drainage, everything I plant eventually dies off, the roots having drowned and rotted off. Any suggestions as to what I could plant there - ideally something evergreen, growing to about three or four feet tall! A tall order methinks!
I would start by trying to improve the drainage in the soil before planting.
our garden v heavy clay but luckily lots seems to thrive, i;'m just learning,also only been in house 4 months, have been going through lots of horticultural grit when i created new beds where was paved,clematis supposed to like cool (damp?) roots
To improve heavy clay soil it is recomended that grit is added-
I find heavy clay responds best to loads of well rotted Farm yard manure, compost or other humus such as cheap growbags.The fibre stops the clay sticking together into a large lump.About a 50/50 mix if possible.
To improve drainage I would add grit and sharp sand,
How high is the wall Poly-anthus and also - do you have planting on the top part? Something there would help soak up some of the excess too. Another alternative is to get some extra drainage in the top area - dig out some vertical 'pipes' and fill with gravel to create mini soakaways which will divert a bit of it farther into the back of that part. All the above suggestions too- cover all bases! Clematis need good drainage though.
I live in west central Scotland - not where that photo is...
Thanks everyone for your replies. The wall is about three feet high and has gravel at the top. The gravel area does have a wide border at the back, against the fence and lots of things are growing there quite happily. I have been digging lots of compost into the borders, but the area under the gravel is, I know, compacted heavy clay with lots of large stones in it. Digging that lot up is not an option - not as young as I used to be!! . Thanks Verdun for the hydrangea suggestion - didn't realise it would grow in very wet soil, and the fern suggestion is definitely an option. Thanks again everyone.