Yellow clematis new leaf growth vigor is contingent on site and environmental conditions. Clematis demands full sunshine more than six hours daily with some partial shade or protection during the hottest part of the afternoon. Air should circulate freely around the plant and soil must be rich, well draining and with a pH level of approximately 7.0. Yellow clematis roots appreciate a cool, wet environment.
The root system plays a fundamental role in encouraging yellow clematis new leaf growth. Plant the crown 1 to 2 inches beneath the soil's surface with the earth packed firmly and watered well supporting the roots. Neighboring plants should possess shallow, noninvasive roots minimizing competition for water and nutrients.
The clematis species slowly establishes itself. Very little growth and few blooms are common during the first growing season. The plant demands at least 1 inch of water weekly. If the yellow clematis was transplanted, the growth of new leaves is slow, as the plant attempts regenerating its roots.
New leaf growth is drastically hindered if the plant develops a leaf spot disease, which is caused by the fungus Ascochyta clematidina. When afflicted, the stem collapses just as new flowers are about to open. A few days later, the leaves wilt and turn black. Remove diseased stems. Unaffected areas typically exhibit new flower and leaf growth.