My son and his family visited the volcanic area of the North Island ,(NZ),back at Xmas time and wanting to experiment with planting in a rock block I asked them to keep an eye out for some largish pieces of pumice.
They bought home 3 rocks ,two of them with angular sides ,(from high up on the banks of a stream), while the remaining one was from a lake front ,very smooth and rounded ,showing what I presume was the result of wave activity.
Finally planted up the largest block last weekend and the following pics show the process and some of the cuttings/seedlings used.
I was surprised, firstly on how soft the material was , (so I was able to quickly drill 16 holes), and then also at the high moisture level of the rock,(it had been dumped on the ground in a shady spot for the last 6 months).
Initially I had planned to plant out using a number of very small Lewisia tweedyii seedlings to see if I could over winter them outside, however I ‘chickened out’ :rolleyes: deciding I'd use the second smaller angular rock for that purpose at a later date once it dried out somewhat.
Will be interesting to see how successful this all turns out ;D--did i drill the holes too big? :-\--were some of the cuttings too large ? :-\--should i have been more adventurous in the selection of plant material ? :-\----- and in respect of the eventual Lewisia tweedyii planting ,will my 1 metre of rainfall pa be a problem ?.....
In any case my difficulty at the moment is figuring out how to incorporate the finished rock into the garden or ……maybe a largish trough….