Drought and watering, request your experiences
On the current thread on 'Arethusa' there was some discussion of the Earthkind trials and watering roses during drought or not watering them. I thought it would be useful to gather some information from you individual gardeners about your various situations, soil, climate, weather, whether you water in dry weather, and what the results are. We don't water after the first year--for the most part--and this policy works for us. It might not work for other people, though, who garden in different conditions, or who want different results. That's what I want to find out, and I hope to hear from many of you.
I've talked plenty about our garden, but will risk boring you all and restate here. We're in the hills at about 1400 ft above sea level, southern exposure, steep slope, very heavy clay soil to a depth of several feet in most places. Our average annual rainfall is about forty inches. We're just below the 45th Parallel (central Oregon; Bangor, Maine), which means that we have short winter days and long summer days. Our summers are hot and dry, with low atmospheric humidity and comfortable temperatures at night; winters are chilly and wet, with temperatures running from the high twenties through the low forties much of the time, and seldom dropping below 20F. We get a good deal of snow, but it doesn't stay around long. We're probably in USDA Zone 7. Our climate is mild enough that we can grow olives and Tea roses, but we have enough winter chill to grow cherries, tulips, peonies, and lilacs.
We have two garden zones. One is the shade garden, with a drainage running through it: it's cooler, moister, shadier, and more protected from wind than the big, or sunny garden. That garden is open to full sun and all the wind that roars through our valley. We're trying to get trees and shrubs growing there, but it's a slow business, and until they get some size on them the sunny garden will suffer all the disadvantages of exposure.
Our garden currently has, probably, about five hundred roses, and of course hundreds of other plants. We water it all with one hose. This is deliberate: it means we don't water more than is necessary to keep plants alive. We water plants the first year only. Naturally we try to select plants that can take a summer drought. Every year we have two to four months in which we get little to no rain, that is, no more than a centimeter in that period. We plant thickly and mulch heavily with hay, which helps keep the ground cool.
Our climate seems to me to be on the cusp between Mediterranean and continental climate. Many classic English garden plants do well here, but so do Mediterranean plants like olives and Italian cypresses. But the weather varies considerably from year to year. The last two years have been very wet and cold, and the Teas and Chinas have been miserable, many ornamental sages have died and the rosemary has suffered, and the olives have frozen back; while the once-blooming old roses have been glorious. Some years back we had a run of warm and dry winters, and the warm climate roses were healthy and vigorous, though we worried about drought.
The results of our dry gardening are that almost all our plants survive droughty periods. The reblooming roses don't flower once they get really dry, and if the autumn rains start late, well into October, they may not flower even in the fall. This is yet another reason to have many different plants in the garden, and to pay attention to structure: so that if the roses are sad or out of bloom there will be other things to enjoy.
I believe in sustainable gardening, and hope this thread can be a start on thinking about that, but I want it to be clear that I'm not telling anybody what they should be doing. We can go months without watering and the garden does well enough, but perhaps this is because we have abundant annual rainfall, and soil that is both heavy and deep. I hope many of you will write about your garden conditions and help make up a kind of anecdotal database and a starting point for thinking about water in the garden.