Hi Ian
I love your bulb log and your coverage of troughs
Following your advice to build up the troughs, i rebuilt my flat trough adjacent to my house which you saw. I used builders sand and covered it with pieces of natural tufa. Much of there tufa was rooted deeply in the trough to wick up water but the smaller top pieces are just fitted on top.
Yes it looks much better, but unfortunately, the entire thing dries out very quickly. So even with the fall rains we have bee getting i have to water it to keep it hydrated. Since it is so dry i have plated Lewisia redivia seedlings on top and they seem to be ok for the past few weeks.
I wonder if your method to build up to reduce sun exposure and conserve water is a function of your cool wet northerly climate?
do others located in hotter and dryer locations have issues with tall troughs drying out?
The photos below show this trough today.
The size is 30" wide x 20"deep x 13" tall and has two ~1.5" holes in the bottom. The mound extends 6" plus above the trough rim. The trough well is filled with bricks, broken concrete, rocks and sand and local soil up to 5 inches below the rim (fill set in place in spring 2009) and builders sand is used above that level.
The hyper tufa trough was made of cement, perlite and peat moss formed around a stiff 14 gauge fence wire frame. We forgot to add dye to the mix, so the color is natural cement. Being in use for 4.5 years in the weather this trough has not taken up any of the lichens and moss so beautifully shown on your troughs.