We are enjoying the rare Penstemon baccharifolius this summer in our high/dry crevice garden. This species is native to limestone ledges up to 6,500′ elevation from the Edwards plateau in Texas south into Northern Mexico. This species hates our summer rains, and we had given up on growing this until we built our alkaline crevice garden a few years ago. Now it thrives, growing in 3′ deep Permatill gravel.
That is remarkable. Planted in what season so as to assure root growth would be adequate?
We don’t find the planting season matters. In crevice gardens, roots grow at extremely fast rates, and can easily reach 3′ long in just 1-2 weeks. If we plant in summer, we add some supplemental water for the first 1-2 weeks.