To my delight and surprise in the last 1,5 years of my new garden I have lost only 2 plants, which I consider entirely due to the irrigation system and the choice of drought-tolerant plants. Even after 6 months' drought the garden looked green in September. This is all of course very controversial and I feel guilty about my water consume. On the other hand the clay soil seems to retain moisture very well especially under the geotextile and gravel. This autumn has been, however, unexceptionally rainy, with a torrential rain 28th September of about 120mm on one day. When I came there the next time in the end of October I found the Ceanothus looking awful. When I digged it out, it was sitting in a black, crumbly, moist soil full of rainworms! The kind of a soil suitable for roses. What had happened? While planting on the last day of my trip, I ran out of sand and perlite, and improved the soil with rotted horse manure, that's all I had. So in one year the soil had turned into a very fertile soil, but not at all suitable for a Ceanothus. So with a clay soil there are possibilities, but not everything goes. The way they irrigate in my area, every night shortly keeps this type of soil moist, but avoids compacting and waterlogging.