Maybe starting over is the answer. There is a saying: “Plant it well and feed generously every year and you’ll have success.” This can be a new motto.
Most small-flowering hybrids are trouble-free, but the large flowering vines are more plagued by pests and clematis wilt. Other troubles can come from rabbits, mice, voles, slugs or earwigs. There are treatments for these, and none are too drastic.
The way to grow beautiful clematises is in the original plant. Look for plants that have at least four root shoots. Remove all soil around the roots and spread them out. Mix one part of well-decomposed manure and three parts good soil. Dig a hole, then place your clematis container in the it to see if the plant is 3 inches below the soil line. Place the clematis in the hole, spread the root, then fill around the plant with the new soil mixture.
Watering during the summer is critical, as a clematis requires five to 10 quarts a week. If the plant cannot be reached by a hose, use a bucket to water around the plant’s roots; no overhead watering!
Feeding the plant during the gardening season is recommended, especially after midseason deadheading or pruning. But no pruning or feeding after August, which might stimulate growth too late into the fall. Also, it is important to keep the roots cool. One way to do this is to plant a low-growing plant or ground cover around the bottom of the clematis or to mulch heavily.
Mildew is an enemy of clematis and can only be controlled by a preventive fungicide. If an outbreak occurs, cut back the plant down to the ground, apply the fungicide and wait for sprouts to reappear.
Clematis wilt is another fungal enemy. An infected plant appears healthy, flushed with booms and then the vines suddenly turn a brownish black and wither. There is no cure for this disease, but you can try pruning the plant to the ground, burning the debris and then cleaning your pruners with bleach to prevent the spread of the fungus. The vine may reappear next year.
This seems like a lot of work, but it is worth it.
In the fall I am traveling to the Guernsey Islands, where clematises are plentiful. I look forward to enjoying all the beauty.
“That beautiful season the summer! Filled was the air with a dreamy and magical light; and the landscape lay as if new created in all the freshness of childhood.”
– Henry Wadsworth Longfellow