It may be that a flat, sunny border cannot be spared for you, but that if you choose you may annex a grass-grown bank or slope of a hill going up to a stone wall or to shrubs. We will tell you how we once saw a place of this kind made into a charming rock garden with some blocks of limestone and a few days’ labour. The bank in this case led from an upper lawn to a lower one, and had a south aspect. The turf was all removed, the soil was thoroughly broken and mixed with sand, and then slabs of limestone were mixed into it, each one with a slight upward tilt, so as to hold the earth and catch the rain. The great point to remember about rock gardening is that every stone or rock should be wedged into the soil a little slantwise, so that the hidden end slants down and the end you see slants up. You soon find out an elementary truth of this kind for yourself if you try to grow things in a badly-made wall or rockery. We once watched someone struggle with a loosely built granite wall that tilted a little towards him, and which had no soil in its crevices. He tried stuffing in earth, but as the slant was wrong it fell out as it dried. No rain reached the roots of his plants because the top stones sheltered the lower ones, so nothing that needed moisture would live. Perhaps in the course of years he might have coaxed some of the house-leeks to find a lodging there; but as he wanted a wall garden clothed in spring with hanging sheets of flowering plants, the only way was to pull the wall down and build it properly. Then it had earth packed into every crevice, and the stones so arranged that the rain could reach every plant set amongst them. Some plants, it is true, will live on next to nothing, but there are very few that will do without rain and will survive when their roots have reached a hollow place amongst stones.