It’s wet, with predictable results
Along the southern boundary of the back half of the rear garden is a shallow depression that runs a hundred feet or more to the back of the property. From beneath the concrete footer of the garden shed a damp weather spring emanates, and in much of the year water runs through this low area, alternately peaking above ground and then disappearing into small sink holes. In wet seasons there is often standing water for weeks at a time, but in summer the swale typically goes bone dry. But, not this year, and this has resulted in predictably dire circumstances.
I would not have planted the witch hazel, evergreen hollies, or Western red cedars if I had realized this area would remain constantly wet. I have little doubt that it was much drier when these were planted, and in fact it seems that the area as a whole has sunk in recent years. The back third of the rear garden is wetter than usual, and I fear that even when this damp summer passes there will be problems, and some long established plants will have suffered irreparable harm.
The witch hazel (Hamamelis x intermedia ‘Arnold Promise’ above) was planted around fifteen years ago at the upper, slightly drier edge of the depression, and it’s grown past ten feet tall and wide. In past years there’s been a time or two when it began to defoliate in late summer when the weather was hot and dry, but I’ve never seen problems from excess dampness. Now, leaves are dropping prematurely, and I wonder if damage to its roots will spell its doom.
In the same area the leaves of the Franklin tree (Franklinia alatamaha, above) are smaller, and more sparse than usual, and I suspect that continually damp soil is the reason. Neither Franklin tree or witch hazel is tolerant of wet soils, and of course if I knew at the time that the area would be this wet I would have planted them on higher ground.
There are plants that flourish in wet ground, but many that are recommended for moist soils are not intended for constant wetness. There is a considerable difference between moist and wet, and this year Rodgersia and turtleheads (Chelone lyonii ‘Hot Lips’, above) have struggled in the wettest spots. But, Black chokeberry (Aronia melanocarpa) and buttonbush (Cephalanthus occidentalis, below) seem quite content in the spot where water stands long after other areas have dried.
The white beautyberry (Callicarpa dichotoma ‘Albifructus’, below) is planted on a slight rise in the wettest area, and it shows no negative effect from the wetness, but Blue Mist shrubs (Caryopteris x clandonensis) planted a few feet away are barely hanging on. I fear that the time for drier ground this summer is running short as August draws to a close, and if September should turn wet from tropical storms and remnants of hurricanes as in recent years I will expect more problems.
There seems nothing can be done to remedy this situation, but to wait and hope. Plants are often more resilient than the gardener has any right to expect, so perhaps all will survive. Certainly, the long term damage will be difficult to assess until next spring, and then I hope that I’m not searching for replacement plants that will tolerate the wetness. The garden changes constantly, and last year’s problems are often forgotten and replaced by new worries. I’ve been doing this garden long enough that I accept these ups and downs, but problems are more often related to too little water, rather than too much, and anticipating the worst, I’ll be heartbroken to lose these long established treasures.