My grandmother spent about a billion hours a year mulching, hydrating, feeding, clipping and worrying over several spiky rose plants. In return, she got back six or seven blooms per summer. I, on the other hand, have profusions of blossoms that appear as early as April and continue into the fall. I spend about 15 minutes every two weeks cutting them back and watering them.

There is no killing a rose bush in San Francisco. They will bloom no matter what horrible mold or evil bug attacks them. As far as I can tell, roses will thrive even if you only water them once a week in the summer and not at all in the winter.

The difference between me and my grandmother is zones. I am in Zone 9. She is in Zone 4. Apparently, so the web tells me, the country is divided into gardening zones. Greenhouses categorize and sell plants by zone. Much like raising children, it is bad form to compare them and worse to imply that one is superior to another, but it is impossible not to notice that Zone 9 supports the flowering plants that everyone wants in the garden and Zone 4 supports mostly fir trees.

So, this week, thorny points go to San Francisco. Keep up the good work.